Block 11 Week 1 Flashcards
Foetal development up to 12 weeks
Day 0 - fertilization in ampulla - zygote
Day 0-4: mitosis keeps happening
We end up with the morula (16 cells) by day 4
Day 6: implantation in uterus. Now called Blastocyst
Within the first week the cells of the morula reorganise to form a cavity, known as the blastocyst cavity ( blastocoel). Some of the cells move towards the outer edge ( form the outer cell mass) and another group together (inner cell mass).
Trophoblast – the outer cell mass. Trophoblast contacts with the endometrium of the uterus to facilitate implantation and the formation of the placenta.
Embryoblast - Responsible for the formation of the embryo itself.
From this point the morula is known as the blastocyst.
During the second week the trophoblast and embryoblast divide into increasingly specialised cells.
Trophoblast (outer cell mass) - syncytiotrophoblast (multinucleated) and cytotrophoblast (mononucleated)
Embryoblast (inner cell mass) - epiblast and hypoblast (bilaminar disc), forming a two layered structure called the bilaminar disc.
The amniotic cavity forms within epiblast.
What will the epiblast and hypoblast become?
Epiblast: Amniotic sac
-The epiblast develops into the endoderm, mesoderm, and ectoderm.
Hypoblast: Yolk sac
-The yolk sac is initially responsible for fetal nourishments and circulation between the mother and fetus (before the placenta develops).
B-hcg
Synctiotrophoblast makes something called B-hcg which is the chemical we use to detect pregnancy in pregnancy test
Ectopic pregnancy and placenta previa
- foetus growing in fallopian tube. Not viable pregnancy
- placenta previa: foetus is growing too low down in the uterus so when it comes to birth their will be complication s as the umbilical chord will be in the way
GASTRULATION
- week 3 is when gastrulation occurs
- we end up forming our 3 germ layers: ectoderm, endoderm, and mesoderm
notochord = nucleus pulposus
neural plate = brain and spinal chord
- folic acid is important for neural tube development
Gastrulation involves the migration, invagination and differentiation of the epiblast. It is largely controlled and orchestrated by the primitive streak.
Primitive streak = primitive groove
Primitive node = primitive pit
The epiblast cells migrate through the primitive groove and towards the hypoblast cells (invagination), they then replace these hypoblast cells. This layer is now called the Endoderm.
More epiblast cells migrate and move down and laterally (ventrally) through the primitive groove and form the mesoderm layer.
We now call the top layer of epiblast cells the Ectoderm
Epiblast – Ectoderm
New layer – Mesoderm
Hypoblast – Endoderm ( they are at the bottom the –end)
The three germ layers are called multipotent and can differentiate into any cell type, they are responsible for forming different tissues in the foetus.
The notochord forms from the mesoderm cells soon after gastrulation is complete.
Neurulation
Neurulation is the process by which ectoderm in the trilaminar embryo develops into the neural tube ( neuroectoderm tube) which is the basis for the nervous system.
Notochord: induces differentiation of overlying ectodermal cells above it to form neural plate
Neural plate ( made of ectoderm): thickening of ectoderm along the midline which causes a depression to form in the centre of neural plate. This is called the neural groove.
The neural folds circle upward and meet in the midline, forming a tube
This tube is pulled below the outer layer of ectoderm → now known as the neural tube
Neural crest cells separate and are located between the neural tube and the ectoderm.
Surface Ectoderm = Epidermis
Neural crest cells = peripheral nervous structures
Neural tube = CNS
At this point the primitive node and the primitive streak begin to fade.
Week 4
- major organ development begins around week 3-4
Week 4:
- neural tube closes
- heart beats ( 4 chamber heart)
- limb formation (4 limbs)
Week 8
- Week 8 we have foetal movement and start referring to our baby as foetus not embryo. ( 8 ‘gait’)
- Week 10: sex of the foetus is recognisable (genitalia - tenitalia)
Describe events during fertilization ?
- Fertilization usually takes place in the fallopian tubes, where the egg awaits the arrival of sperm.
- The sperm must then penetrate the protective layers surrounding the egg. The outer layer of the egg, called the zona pellucida, is broken down by enzymes released by the acrosome, a cap-like structure at the tip of the sperm.
- Once the sperm penetrates the zona pellucida, it binds to the egg membrane. The membranes of the sperm and egg fuse, allowing the genetic material (chromosomes) from both the sperm and the egg to combine.
- The fusion of the sperm and egg results in the formation of a single-celled structure called a zygote. The zygote contains a complete set of chromosomes, half from the mother and half from the father
- The zygote undergoes rapid cell division through a process called cleavage. As the cells divide, a blastocyst is formed.
Ethics around assisted reproduction
- Assisted reproduction refers to medical procedures that aid in the conception of a child. These procedures can include in vitro fertilization (IVF), intrauterine insemination (IUI), surrogacy, and various fertility treatments.
-Respect for Autonomy: Individuals and couples undergoing assisted reproduction should have the autonomy to make decisions about their reproductive choices. Informed consent is crucial, ensuring that individuals understand the potential risks, benefits, and alternatives associated with the procedures.
- Status of the Embryo: The status of the embryo is a complex ethical issue. Some people believe that life begins at conception, while others may have different views. Decisions about the disposition of embryos (e.g., freezing, donation, or disposal) can be ethically challenging.
- Rights and Responsibilities: Surrogacy raises questions about the rights and responsibilities of all parties involved—intended parents, gestational carriers, and the child. Ethical considerations include the potential for exploitation, the well-being of the surrogate, and the rights of the child.
- The use of fertility treatments can result in multiple pregnancies, which may pose health risks to both the mother and the fetuses. Decisions about selective reduction (reducing the number of fetuses) can involve ethical dilemmas.
-Avoiding Exploitation: There are concerns about the commercialization of assisted reproduction and potential profiteering. Ethical guidelines aim to prevent the exploitation of vulnerable individuals or the commodification of human reproductive capacities.
Resource management in NHS ?
The NHS provides a range of services related to fertility, maternity, and prenatal care
- Preconception Care:
GP Consultations: Schedule preconception consultations with your General Practitioner (GP). They can provide advice on preconception health, address any concerns, and ensure that you are in good health before trying to conceive.
Folic Acid and Vitamin Supplements: GPs often recommend folic acid supplements for women trying to conceive to reduce the risk of neural tube defects in the baby.
Fertility Services:
Fertility Assessment: If you experience difficulty conceiving, the NHS offers fertility assessments and treatments. Consult your GP to discuss your situation, and they can refer you to a fertility specialist if necessary.
Fertility Testing and Treatments: Some fertility testing and treatments may be available through the NHS. The availability and eligibility criteria may vary depending on your location.
Antenatal and Maternity Services:
Booking Appointments: Once pregnant, contact your GP to book your first antenatal appointment. This is the beginning of your maternity care journey within the NHS.
Midwifery Care: Maternity care in the NHS involves midwifery support. Midwives provide care during pregnancy, labor, and the postpartum period.
Ultrasound Scans: Routine ultrasound scans are part of NHS antenatal care to monitor the baby’s development and ensure a healthy pregnancy.
Health Visiting and Postpartum Support:
Health Visitor Support: Health visitors provide support and advice on various aspects of infant care, development, and well-being after the baby is born.
Postnatal Care: NHS offers postnatal care to monitor the health of both the mother and the baby. This includes postnatal check-ups and support for breastfeeding.
Parental and Maternity Leave:
Understanding Leave Policies: Be aware of your rights regarding parental and maternity leave. Understand the policies in your workplace and how they align with statutory rights in the UK.
Financial Support:
Maternity Allowance: Explore potential financial support, such as Maternity Allowance, which may be available if you do not qualify for Statutory Maternity Pay through your employer.
Benefits and Entitlements: Understand other benefits and entitlements available to families, such as Child Benefit and Tax-Free Childcare.
Prenatal Classes and Support Groups:
NHS Antenatal Classes: Consider participating in NHS antenatal classes, which provide information and support for expectant parents.
Support Groups: Joining local support groups or online communities can provide additional emotional support and information.
Psychological treatment for IVF patients ?
- Individual Counseling: One-on-one counseling sessions with a psychologist or therapist can provide a private and supportive space for individuals to express their emotions, fears, and concerns related to infertility and IVF.
Couples Counseling: Couples may benefit from joint counseling sessions to enhance communication, cope with stress, and navigate the emotional challenges of fertility treatments together - Psychoeducation: Providing information about the IVF process, potential challenges, and coping strategies can empower individuals and couples. Knowing what to expect and understanding the medical aspects of treatment can reduce anxiety.
Decision-Making Support: Psychologists can assist in decision-making processes, such as whether to continue with additional fertility treatments or explore alternative family-building options - IVF Support Groups: Joining a support group with other individuals or couples going through IVF can offer a sense of community and shared understanding. It provides an opportunity to share experiences, coping strategies, and emotional support.
Online Communities: In addition to in-person support groups, online forums and communities can connect individuals with others facing similar challenges. This can be particularly beneficial for those who prefer virtual interactions.
Pharmalogical treatment for ovulation induction ?
- Ovulation induction is a medical intervention aimed at stimulating the ovaries to produce and release eggs, particularly in cases of infertility where ovulation is irregular or absent
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Oestrogen and FSH relationship
- FSH and LH causes eostrogen production by binding to the theca and granulosa cells on the follicle
- As oestrogen level rise it has a negative feedback effect and causes a decrease in FSH from the anterior pituitary gland.
- As a result of the decrease on FSH some developing follicles will stop developing and die off
- The follicles with the most FSH receptors will continue to grow - dominant follicle - undergo ovulation.
- The dominant follicle continues to secrete oestrogen
-Oestrogen makes pituitary gland more responsive to GnRH so ir releases more FSH and LH ( now oestogen is acting as a positive feedback mechanism)
- The surge in FSH and LH happens 1-2 days before ovulation.
It is responsible for the rupture of the ovarian follicle and release of the oocyte.
Clomiphene Citrate
Clomiphene Citrate (Clomid):
Mechanism of Action: Clomiphene citrate is a selective estrogen receptor modulator (SERM). It works by blocking estrogen receptors in the hypothalamus and pituitary gland, leading to increased secretion of follicle-stimulating hormone (FSH) and luteinizing hormone (LH). This, in turn, stimulates ovulation.
Administration: Typically taken orally for a specific number of days during the menstrual cycle.
Letrozole ( Femara)
Letrozole (Femara):
Mechanism of Action: Letrozole is an aromatase inhibitor that reduces estrogen production, leading to an increase in FSH and subsequent ovulation.
Administration: Usually taken orally for a specified number of days in the early part of the menstrual cycle.
Gonadotropins
Gonadotropins:
Types: Injectable gonadotropins, such as follicle-stimulating hormone (FSH) and luteinizing hormone (LH), can be administered to stimulate the ovaries directly.
Administration: Administered by injection, typically subcutaneously or intramuscularly. The dosage and timing are closely monitored to prevent complications like ovarian hyperstimulation syndrome (OHSS).
Human Chorionic Gonadotropin (hCG)
Human Chorionic Gonadotropin (hCG):
Mechanism of Action: hCG is often used in conjunction with other medications to trigger ovulation. It mimics the action of LH, inducing the release of mature eggs from the follicles.
Administration: Administered as an injection after the development of mature follicles, timed to coincide with the expected time of ovulation.
Metformin
Metformin:
Indications: Metformin is commonly used in the treatment of polycystic ovary syndrome (PCOS) and insulin resistance, which can contribute to ovulatory dysfunction.
Mechanism of Action: It helps regulate insulin levels, which, in turn, can normalize ovarian function and promote regular ovulation.
Bromocriptine or Cabergoline
Bromocriptine or Cabergoline:
Indications: These medications may be prescribed in cases where elevated prolactin levels are causing ovulatory issues.
Mechanism of Action: They reduce prolactin levels, helping to restore normal ovulation.
Aromatase Inhibitors
Aromatase Inhibitors (Anastrozole):
Indications: Aromatase inhibitors are sometimes used as an alternative to clomiphene citrate for ovulation induction.
Mechanism of Action: Similar to letrozole, they inhibit the production of estrogen, indirectly stimulating the release of FSH and promoting ovulatio
Limitations of assisted reproduction techniques ?
While assisted reproduction techniques have provided hope and solutions for many couples struggling with infertility, they also come with certain limitations and challenges. Here are some notable limitations of assisted reproduction techniques (ART):
Success Rates:
Varied Success Rates: Success rates for ART can vary widely depending on factors such as age, underlying fertility issues, and the specific technique used. While many couples do achieve successful pregnancies, there is no guarantee of success in every case.
Financial Costs:
Expense: ART procedures, including in vitro fertilization (IVF), can be expensive. The financial burden may limit access for some individuals or couples, and insurance coverage for these treatments may vary.
Emotional and Psychological Stress:
Emotional Strain: The emotional toll of fertility treatments can be significant. The uncertainty, repeated cycles, and the potential for both success and failure can contribute to stress, anxiety, and depression.
Multiple Pregnancies:
Risk of Multiple Births: Fertility treatments, particularly the use of ovulation-inducing medications and assisted reproductive technologies, increase the risk of multiple pregnancies (twins, triplets, etc.). Multiple pregnancies carry higher risks for both mothers and babies.
Ovarian Hyperstimulation Syndrome (OHSS):
Complications from Medications: Ovulation-inducing medications, particularly injectable gonadotropins, can lead to ovarian hyperstimulation syndrome, a potentially serious condition characterized by enlarged ovaries and fluid imbalances.
Ethical and Legal Issues:
Ethical Considerations: Some people may have ethical concerns related to the creation, selection, and disposition of embryos, as well as issues surrounding surrogacy and reproductive technologies.
Legal Complexities: Legal issues can arise in cases of gamete donation, surrogacy, and custody disputes involving assisted reproductive technologies.
Limited Treatment Options for Some Conditions:
Certain Infertility Causes: Some medical conditions or infertility factors may not be amenable to treatment with existing assisted reproduction techniques. For example, severe male factor infertility or certain structural abnormalities may limit treatment options.
Age-Related Factors:
Diminished Ovarian Reserve: As women age, the quantity and quality of their eggs decrease, impacting the success rates of ART. Advanced maternal age is associated with lower chances of success and a higher risk of chromosomal abnormalities.
Health Risks and Side Effects:
Medical Complications: Fertility treatments carry some health risks, such as ectopic pregnancies, gestational diabetes, and high blood pressure during pregnancy. Additionally, there can be side effects associated with the use of hormonal medications.
Limited Control Over Genetic Factors:
Genetic Issues: ART does not guarantee the absence of genetic abnormalities in embryos. Pre-implantation genetic testing (PGT) can be used to screen embryos for certain conditions, but it is not foolproof.
Summarize the adverse effects of alcohol and smoking abuse on development ?
Alcohol and smoking abuse during pregnancy can have severe adverse effects on fetal development and long-term health outcomes. Here’s a summarized overview of the impact of alcohol and smoking on development:
Alcohol Abuse:
Fetal Alcohol Spectrum Disorders (FASD): Prenatal exposure to alcohol can lead to a range of developmental disorders collectively known as Fetal Alcohol Spectrum Disorders. These can include physical, behavioral, and cognitive abnormalities.
Physical Abnormalities: Facial deformities, growth deficiencies, and abnormalities in organs such as the heart and kidneys can occur.
Neurodevelopmental Issues: Alcohol exposure during pregnancy can cause intellectual disabilities, learning difficulties, and behavioral problems in children.
Behavioral and Cognitive Impairments: Children with FASD may exhibit issues with attention, memory, impulse control, and social skills.
Smoking Abuse:
Low Birth Weight: Smoking during pregnancy is associated with an increased risk of delivering a low birth weight baby, which can have long-term health implications.
Preterm Birth: Pregnant women who smoke are more likely to experience preterm labor and delivery, which is associated with various health risks for the infant.
Respiratory Issues: Exposure to maternal smoking increases the risk of respiratory problems in infants, such as asthma and respiratory infections.
Developmental Delays: Children born to mothers who smoke during pregnancy may be at a higher risk of developmental delays, including cognitive and language deficits.
Sudden Infant Death Syndrome (SIDS): Infants born to mothers who smoke are at an increased risk of SIDS, a sudden and unexplained death during sleep.
Common Adverse Effects (Alcohol and Smoking):
Placental Abnormalities: Both alcohol and smoking can adversely affect the placenta, leading to reduced oxygen and nutrient supply to the developing fetus.
Cognitive and Behavioral Issues: Exposure to either substance during pregnancy can result in cognitive impairments, learning difficulties, and behavioral problems in children.
Increased Risk of Miscarriage: Both alcohol and smoking abuse are associated with an increased risk of miscarriage and stillbirth.
Nutritional needs in pregnancy ?
Pregnancy is a critical period during which the body’s nutritional needs increase to support the growth and development of the fetus. Meeting these needs is essential for the health of both the mother and the baby. Here are key nutritional needs during pregnancy:
Folic Acid:
Role: Essential for neural tube development in the early stages of pregnancy, reducing the risk of birth defects.
Sources: Leafy green vegetables, fortified cereals, legumes, and supplements as recommended by healthcare providers.
Iron:
Role: Critical for preventing anemia and supporting the increased blood volume during pregnancy. Iron is necessary for the development of the baby’s brain and blood.
Sources: Red meat, poultry, fish, beans, lentils, fortified cereals, and dark, leafy greens.
Calcium:
Role: Vital for the development of the baby’s bones, teeth, heart, and muscles.
Sources: Dairy products, fortified plant-based milk, leafy green vegetables, and calcium supplements if needed.
Protein:
Role: Important for the growth of the baby’s organs, muscles, and tissues.
Sources: Meat, poultry, fish, eggs, dairy products, legumes, nuts, seeds, and plant-based protein sources.
Omega-3 Fatty Acids:
Role: Essential for the development of the baby’s brain and eyes.
Sources: Fatty fish (e.g., salmon, mackerel), walnuts, flaxseeds, chia seeds, and omega-3 supplements if recommended by a healthcare provider.
Vitamin D:
Role: Aids in the absorption of calcium and promotes bone health.
Sources: Sunlight exposure, fortified dairy or plant-based milk, fatty fish, and vitamin D supplements if needed.
Vitamin A:
Role: Important for vision, immune function, and skin health.
Sources: Orange and yellow fruits and vegetables, dark leafy greens, eggs, and sources of beta-carotene.
Vitamin C:
Role: Supports the immune system and helps the body absorb iron.
Sources: Citrus fruits, strawberries, bell peppers, tomatoes, and broccoli.
Zinc:
Role: Critical for fetal growth and immune function.
Sources: Meat, poultry, dairy products, nuts, seeds, and legumes.
Iodine:
Role: Important for the development of the baby’s brain and nervous system.
Sources: Iodized salt, dairy products, fish, and supplements if recommended by a healthcare provider.
Fiber:
Role: Helps prevent constipation, a common issue during pregnancy.
Sources: Whole grains, fruits, vegetables, legumes, and nuts.
Hydration:
Role: Essential for maintaining amniotic fluid, supporting increased blood volume, and preventing dehydration.
Sources: Water, herbal teas, and hydrating foods like fruits and vegetables
Understand the interplay of socioeconomic disadvantage with adverse outcomes in pregnancy ?
The interplay of socioeconomic disadvantage with adverse outcomes in pregnancy is complex and multifaceted. Socioeconomic status (SES) encompasses various factors such as income, education, employment, and access to resources. Individuals facing socioeconomic disadvantages often encounter barriers that can negatively impact maternal health, prenatal care, and overall pregnancy outcomes. Here are key aspects of this interplay:
Access to Prenatal Care:
Challenge: Socioeconomically disadvantaged individuals may face barriers in accessing timely and adequate prenatal care.
Impact: Delayed or insufficient prenatal care can result in missed opportunities for early detection and intervention regarding potential complications.
Nutritional Disparities:
Challenge: Limited financial resources may lead to poor nutrition, inadequate prenatal supplementation, and challenges in accessing healthy foods.
Impact: Inadequate nutrition can contribute to maternal health issues, low birth weight, and developmental problems in the baby.
Stress and Mental Health:
Challenge: Socioeconomic disadvantage is often associated with chronic stressors, including financial strain and social disparities.
Impact: Prolonged stress can negatively affect maternal mental health, potentially leading to adverse pregnancy outcomes such as preterm birth and low birth weight.
Environmental Exposures:
Challenge: Individuals in lower SES groups may be more likely to live in environments with limited access to clean air, safe housing, and low exposure to toxins.
Impact: Environmental factors can contribute to complications such as preterm birth, birth defects, and respiratory issues in infants.
Limited Health Literacy:
Challenge: Lower levels of education and health literacy can hinder understanding of prenatal care recommendations and healthy behaviors.
Impact: Limited health literacy may result in suboptimal health behaviors, inadequate self-care, and missed opportunities for preventive measures.
Access to Healthcare Facilities:
Challenge: Geographical and financial constraints may limit access to quality healthcare facilities.
Impact: Limited access may result in delayed care, reduced monitoring of high-risk pregnancies, and increased maternal and infant mortality rates.
Social Support:
Challenge: Socioeconomic disadvantage may be associated with limited social support networks.
Impact: Adequate social support is crucial during pregnancy. Lack of support can contribute to increased stress, mental health issues, and difficulties in coping with the challenges of pregnancy.
Occupational Hazards:
Challenge: Certain occupations associated with lower SES may involve exposure to physical and environmental hazards.
Impact: Occupational risks can contribute to adverse outcomes, including preterm birth, low birth weight, and developmental issues.
Behavioral Risk Factors:
Challenge: Socioeconomic disparities can be linked to higher rates of unhealthy behaviors such as smoking, substance abuse, and inadequate physical activity.
Impact: These behaviors increase the risk of adverse pregnancy outcomes, including preterm birth, low birth weight, and developmental issues.
What are doctors supposed to do if they consciously object to a particular procedure ?
When a doctor conscientiously objects to a particular medical procedure or intervention due to personal, religious, or moral beliefs, it is generally recognized that the doctor has the right to exercise conscientious objection. However, the specifics of how this is managed can vary based on legal, ethical, and institutional guidelines. Here are some common considerations:
Informed Consent and Disclosure:
Doctors who conscientiously object to a procedure are typically obligated to inform the patient of their objection during the informed consent process. This allows patients to make informed decisions about their care.
Referral to Another Provider:
In many cases, doctors who conscientiously object are expected to provide the patient with information about alternative providers or facilities where the requested procedure can be performed. This ensures that patients can still access the care they need.
Timely and Accessible Referral:
Doctors should make the referral process as smooth and timely as possible to avoid delays in the patient’s treatment. Timely access to alternative providers is crucial, especially in cases where time-sensitive interventions are needed.
Institutional Policies:
Some healthcare institutions may have specific policies in place to address conscientious objection. Doctors should be aware of and follow these policies, which may outline the steps to be taken in case of objection.
Professional Guidelines:
Professional medical organizations may provide guidance on conscientious objection. Doctors can refer to ethical guidelines established by medical associations to ensure that they navigate objections in a manner consistent with the principles of the medical profession.
Legal Framework:
Legal considerations can vary by jurisdiction. In some places, laws may protect a doctor’s right to conscientiously object, while in others, there may be legal obligations to ensure that patients have access to the requested care.
Balance of Patient Rights and Provider Conscience:
The challenge lies in balancing the patient’s right to receive appropriate medical care with the doctor’s right to conscientiously object. Striking a balance often involves ensuring that patients have access to necessary care while respecting the provider’s moral or religious beliefs.
Alternative Care Pathways:
Healthcare institutions may explore alternative care pathways that respect both the doctor’s objections and the patient’s needs. This may involve collaboration with other healthcare professionals or services.
Ethical and legal considerations to termination ?
Autonomy and Reproductive Rights:
Principle: Respect for individual autonomy and reproductive rights is a fundamental ethical consideration. Women have the right to make decisions about their own bodies and reproductive choices.
Right to Life:
Principle: The ethical debate often involves the conflict between the woman’s right to autonomy and the potential rights of the developing fetus. Different ethical perspectives place varying emphasis on the moral status of the fetus.
Medical Indications:
Principle: Ethical justifications for termination often include considerations of the woman’s health, life, or in cases of severe fetal abnormalities. Balancing the well-being of the woman against potential harm to the fetus is a complex ethical dilemma.
Quality of Life:
Principle: Ethical discussions may extend to considerations of the potential quality of life for the child, especially in cases of severe disabilities or genetic abnormalities.
Counseling and Informed Consent:
Principle: Ensuring that individuals seeking termination receive comprehensive counseling and have access to accurate information is crucial for informed decision-making.
Legal Considerations:
Abortion Laws:
Variability: Abortion laws vary widely across jurisdictions. Some countries or regions may permit abortion on request, while others may have restrictions or outright bans. The legal landscape often reflects societal and cultural attitudes toward abortion.
Gestational Limits:
Legal Restrictions: Many jurisdictions impose gestational limits on when abortions can be performed without specific medical indications. Late-term abortions are often subject to stricter regulations.
Medical Indications:
Legal Grounds: Legal frameworks often allow for termination in cases of medical necessity, threat to the woman’s life or health, or severe fetal abnormalities. The specific criteria can vary.
Informed Consent and Counseling:
Legal Requirement: Laws may require that women receive counseling and give informed consent before undergoing the procedure. This is intended to ensure that the decision is voluntary and well-informed.
Healthcare Provider Conscience Clauses:
Legal Protections: Some jurisdictions have conscience clauses that protect healthcare providers who conscientiously object to performing or assisting in abortions. However, these protections must be balanced with ensuring access to care for patients.
Access to Services:
Legal Requirement: Legal frameworks should ensure that women have access to safe and legal abortion services, regardless of their socioeconomic status.
Privacy and Confidentiality:
Legal Protections: Laws often protect the privacy and confidentiality of individuals seeking abortion services to avoid unwarranted intrusion into their personal lives.
Preventing Coercion:
Legal Safeguards: Legal systems aim to prevent coercion or undue pressure on women to undergo abortions against their will. Ensuring that decisions are made freely and voluntarily is a legal consideration.
Hormones of pregnancy
- Eostrogen is synthesized by the ovaries, specifically the granulosa cells
- In granulosa cells we convert Adrostenedione to Estradiol using the enzyme Aromatase
Types of oestrogen:
- Estradiol (ovary) (strongest eostrogen)
- Estrone (fat) (middle)
- Estriol (placenta) (weakest oestrogen)
Estrogen sexual development :
- stimulates production of breast tissue, endometrium and vagina.
Estrogen extragenital development:
- increase in clotting factors
- increase in HDL
- decrease in LDL
- increase in osteoclast apoptosis
Pregnancy
Around this time, the corpus luteum makes a lot more progesterone relative to estrogen, and the low estrogen to progesterone ratio is necessary for implantation.
At this early stage, there are two parts to the blastocyst - an inner set of cells that go on to become the fetus, and an outer set of cells called the trophoblast that burrow into the endometrium on day 6 and eventually develop into the fetal part of the placenta.
That trophoblast cells start to produce a hormone called human chorionic gonadotropin or HCG around day 8, and this is important for two reasons.
Pregnancy
One - it’s the hormone that lets the corpus luteum know that there has been a successful implantation into the endometrium, and that it should continue to make estrogen and progesterone.
And it’s the continued presence of estrogen and progesterone that suppresses other ovarian follicles from maturing.
Pregnancy
Two - HCG is the hormone that most pregnancy tests are able to detect, causing the little sign to form which can happen as early as day 9.
Without HCG levels shooting up on day 8, the corpus luteum would start to shrivel up by day 10, and estrogen and progesterone levels would fall.
This would cause the lining of the endometrium to slough off or fall away from the endometrial wall resulting in a period or menses.
Pregnancy
A pregnancy lasts 40 weeks, roughly 9 months, but that is from the last menstrual period, which is usually about 2 weeks before “day 0” of ovulation.
So if you’re counting from “day 0” a pregnancy is only about 38 weeks.
The reason for adding in the extra two weeks is that women usually know the date when their last menstrual period began, but have no way of knowing when they ovulated.
HCG AND FUNDAL HEIGHT
So during the first trimester, which is between week 1 through 13, hormones are being generated by the corpus luteum - mainly estrogen and progesterone.
By around week 9, HCG levels peak, and then begin to fall off which is a signal for the corpus luteum to finally start shriveling up.
Luckily, just as the corpus luteum is shriveling up, the placenta takes over, and specialized trophoblast cells called syncytiotrophoblast cells, make progesterone and estriol which is the most abundant type of estrogen.
The placenta also makes a bit of HCG, as well as another hormone called human placental lactogen or hPL which counters the effect of maternal insulin to help ensure that there’s plenty of glucose available in the blood for the fetus.
Many of the changes in pregnancy are directly related to the growth of the uterus.
The uterus is normally a pelvic organ, but during pregnancy it grows into the abdomen, rising to the level of the umbilicus by 20 weeks gestation and to the xiphoid process by 36 weeks.
The fundal height - which is the distance from the symphysis pubis to the top of the uterus aka the fundus is a good estimate of gestational age; for example, here at 36 weeks you might expect it to be about 36 cm, but at 20 weeks it’d be closer to 20 cm.
CARDIOVASCULAR
To accommodate the needs of mom, an enlarging uterus, and a growing fetus - as well as having some reserve for the blood loss that happens during delivery, the cardiovascular system has to expand.
Pregnancy is called a high volume state because the circulating blood volume increases by 30-50%, which means that an average woman will go from having 5 liters of blood to about 7.5 liters of blood by the third trimester.
The number of red blood cells increases a bit, but there’s a much larger increase in the plasma volume - the portion of blood that doesn’t have red blood cells.
So the hematocrit, or percentage of blood made of red blood cells, actually goes down. This is called “physiological anemia of pregnancy”.
CARDIOVASCULAR
To push this extra blood around, the heart rate goes up by about 20 beats per minute, so this increases the cardiac output.
In response to the increased workload there is a mild hypertrophy of the heart, which does go away after pregnancy.
The high volume state also explains why there’s sometimes a third heart sound or physiologic S3, as well as a split S1 which is where the mitral valve closes slightly faster than the tricuspid valve.
Finally, the blood pressure actually falls a tiny bit, even though more blood’s getting pushed through them, since progesterone causes them to dilate.
Finally, as the uterus enlarges, it pushes up on the diaphragm, nudging the heart slightly upward and shifting the heart’s point of maximum intensity - the spot where it taps against the chest wall - a little bit to the left.
The uterus also presses against the pelvic veins, causing blood to back up, leading to varicose veins as well as swelling in the lower legs and ankles.
When lying down, the uterus presses on the inferior vena cava reducing blood flow back to the right atrium and causing hypotension.
A side-lying position or placing a pillow under the hip can help avoid that.
KIDNEYS AND RESP
The increased cardiac output also means that there more fluid going through the kidneys, increasing the glomerular filtration rate and urinary output.
Combining that increased urine output with direct pressure on the bladder from the enlarging uterus, explains why pregnant women have urinary frequency.
It turns out that the kidneys compensate for the extra workload by increasing in size causing the calyces and renal pelvis to dilate - resulting in physiologic hydronephrosis, and increasing the size of the ureters, causing physiologic hydroureter.
In addition, progesterone causes hypomotility of the ureters.
The increased capacity to store urine and the hypomotility in the ureters results in urinary stasis in the kidneys and increases the risk of an upper urinary tract infection.
The lungs get affected as well. The uterus pushes upwards on the diaphragm, making it harder for pregnant women to breathe comfortably.
There’s some compensation because progesterone relaxes ligaments in the thorax, increasing the transverse diameter of the rib cage - like a bucket handle that swings out, and the anteroposterior diameter of the rib cage - like a handle that pulls up.
These changes increase the tidal volume - the amount of air inhaled or exhaled per breath - and minute volume - the amount of air inhaled or exhaled per minute.
This decreases carbon dioxide levels in the blood causing a mild respiratory alkalosis.
It turns out that this mild alkalosis actually enhances gas exchange across the placenta, making it easier for the growing fetus to get oxygen.
WADDLING GAIT
Finally, in the upper respiratory tract, estrogen causes increased vascularization and capillary engorgement, which can lead to nasal stuffiness, sinus congestion, and nosebleeds.
In addition, progesterone and relaxin, another hormone produced by the placenta, both loosen ligaments around the sacroiliac joints and symphysis pubis in preparation for fetal passage through the birth canal.
This results in a waddling gait sometimes seen during pregnancy, and these two can also cause pain in other joints, like those of the ribs and, or coccygeal or tail bone, all from shifting ligaments.
G.I. TRACT
In the gastrointestinal tract, hormonal changes cause smooth muscle relaxation and decreased peristalsis, which sometimes leads to constipation and bloating - stool softeners might help with this.
It also causes relaxation of the lower esophageal sphincter, which can lead to gastric reflux and heartburn - which can be managed with proton pump inhibitors, like omeprazole.
Many pregnant women also experience “morning sickness” which is nausea that typically happens early on in the pregnancy, but can actually happen any time of day and sometimes persists throughout the pregnancy.
MOOD
High levels of estrogen and progesterone hormones can also affect mood, and the effect can range from mild irritability to severe anxiety and depression, all of which can be very unexpected and disconcerting.
Many women also describe a mental fogginess or decreased ability to concentrate, which may be related to hormonal changes or general fatigue and sleep deprivation.
BREAST MILK
During the pregnancy, estrogen and progesterone also promote breast development and the milk-producing machinery that will go to work after the baby is delivered.
Increased blood flow to the breasts and building of breast tissue may cause symptoms like tingling, fullness, and tenderness.
Estrogen also stimulates the anterior pituitary to produce prolactin, a hormone responsible for milk production and letdown, though the high levels of progesterone present during pregnancy inhibit prolactin’s milk letdown effect until the baby is born and estrogen and progesterone levels fall.
LINEA NIGRA
That anterior pituitary gland also releases more melanocyte stimulating hormone, which causes darkening of the areolae, or the skin around the nipples.
The increased melanocyte activity also darkens the normally unseen stripe of fibrous tissue running down the chest and abdomen from the xiphoid process to the symphysis pubis called the linea alba or white line, transforming it into a darkened line called the linea nigra.
THYROID
Other glands that are affected by pregnancy include the thyroid gland which churns out more thyroid hormone to increase the cellular basal metabolic rate in order to meet the demands of the pregnancy.
HYPERCOAGUABLE
Finally, estrogen also promotes blood clotting by increasing plasma fibrinogen and the activity of coagulation factors, as well as enhancing platelet aggregation - all of which normally promote coagulation.
At the same time, estrogen decreases the activity of antithrombin III, which normally inhibits coagulation.
Therefore, pregnancy is a hypercoagulable state - and it makes sense for it to be this way, so there will be as little bleeding after delivery as possible.
WEIGHT
Normally, women gain 25 to 35 pounds throughout the pregnancy, and that extra weight is mostly due to the increased blood volume, followed by the fetus itself, fat stores, the uterus, and finally the placenta.
The extra weight and the forward shift in the center of gravity, can cause a lordosis and lower back pain.
Women can also get diastasis recti, which is where the uterus puts direct pressure on rectus abdominus muscles making them separate.
In general, this pain can make it tough to get a good night’s rest.
Hormone in Preganancy
Progesterone is synthesized by the corpus luteum and the placenta
- corpus luteum produces progesterone for 14 days after the release of a egg. It will continue to release progesterone if told to by BhCG
- 10th week gestation placenta makes progesterone.
Sexual characteristics:
- Progesterone is pro - gestation it wants a foetus to grow so changes the uterus to accommodate that.
Progesterone sexual characteristics:
- Endometrial spiral artery and glandular development
- inhibit prolactin (no need for breastfeeding till after birth)
- cervical mucus thickening (do not need more sperm after fertilization)
Progesterone extragenital characteristics:
- increase in body temp ( because metabolizing faster to prepare for fetus, temp is higher in the luteal phase )
- inhibits estrogen receptors ( were workings less on profiltering endometrium and more on maturing it) this helps inhibit endometrial hyperplasia
Hormones in Pregnancy
- BhCG: GPCR (binds to extracellular membrane receptor) -> cAMP
- maintains corpus luteum which is gonna lead to continued progesterone production
High BhCG:
- multiple pregancy
- Choriocarcinoma
- Molar preganancy
Low BhCG:
- ectopic preganncy
- abortion
Human Placental Lactogen
- HPL is analog of human growth hormone
- contributes to insulin resistance, so mothers can develop gestational diabetes
Estrogen and Progestogen
- Eostrogen responsible for follicular phase of the menstrual cycle and it build up the endometrium
- Progesterone responsible for luteal phase and the maturation of the endometrium
- Progesterone is pro-gestational; it is responsible for supporting the fetus and preparing the body for pregnancy.
Pregnancy Physiology
- Acrosome - has enzymes which chew through the walls of the egg
- Once sperm has chewed through the wall of the egg another reaction called the cortical reaction now occurs.
- Their are little granules around the whole egg as soon as one is broken by a sperm the granules turn the egg wall into metaphorical cement so no other sperm can get in - so prevents polyspermy
Placenta and Umbilical Cord
The placenta is a temporary organ that develops in the uterus during pregnancy to support the developing embryo or fetus. It connects the developing fetus to the mother’s blood supply. It acts as a bridge between the mother and the embryo or fetus, allowing nutrients and oxygen to flow from mom to fetus and waste products to flow from the fetus back to the mother. The placenta forms a few weeks after the embryo implants in the wall of the uterus.
Placenta
- Deoxygenated fetal blood gets to the placenta through two umbilical arteries, and the blood picks up oxygen and glucose while dropping off carbon dioxide.
- Oxygenated fetal blood then heads back towards the heart through a large umbilical vein.
- That umbilical vein and the two umbilical arteries collectively form the vessels of the umbilical cord.
- Development of these structures goes back to the first week of development, when the fetus is just a little ball of cells called a blastocyst.
- To snuggle deeper into the decidua basalis, trophoblast cells from the outer layer of the fetus assemble into two layers of cells called the cytotrophoblast and the syncytiotrophoblast.
- The multinucleated syncytiotrophoblast grows larger and moves like an octopus deeper into the decidua basalis.
- Around day 14 of development, cells of the syncytiotrophoblast start to form little protrusions called primary villi—each one looks a bit like a tree.
-These primary villi trees form all the way around the fetus, and cells start to clear out from between the primary villi, leaving behind empty spaces called lacunae.
-While this is all happening, arteries and veins from the mother start to grow into the decidua basalis.
Over time, more and more of these little pools of blood develop and they start merging together to form a single large pool of blood with many arteries delivering blood into it and many veins taking blood away.
This large pool is called the junctional zone—because this is where the maternal and fetal circulations come into close contact.
Lots of fetal villi trees next to one another are basically submerged in the pool of maternal blood in the junctional zone.
The villi in the junctional zone start to grow more and more branches, whereas the villi that are outside of it regress.
Placenta
Around day 17 of development, fetal mesoderm cells enter the primary villi and they start forming tiny blood vessels, establishing a basic system of fetal arteries, capillaries, and veins within each villi.
The villi capillaries connect with blood vessels in the umbilical cord, and this links up the placental and fetal circulatory networks.
At this point, the placenta is really starting to take shape.
The basal plate, sometimes called the decidual plate, is the thick layer of decidua basalis tissue that the maternal arteries (called spiral arteries) and veins have to pass through to get to the junctional zone.
This is the maternal contribution to the placenta.
On the other side, we’ve got a forest of villi trees called the chorionic frondosum emerging out of the chorionic plate.
The chorionic plate is parallel to the basal plate, sandwiching in the junctional zone. This part is the fetal contribution to the placenta.
Now, while the placenta has been forming on one side, a space forms around the fetus.
This space forms as cells sort of move out of the way, and a new cavity called the chorionic cavity comes into being.
Within the chorionic cavity is the amniotic cavity, the yolk sac, and the fetus itself.
The wall of this cavity where the syncytiotrophoblast villi regressed is known as the chorion laeve.
Stuck to the outside of the chorion laeve is a thin layer of decidua called the decidua capsularis.
On an ultrasound, the chorionic cavity shows up as a relatively large, dark space, and it’s used to identify a pregnancy even before the fetus can be seen.
During the fourth and fifth months of development, decidual septa or walls form and divide the placenta into somewhere between 15 and 20 different regions, called cotyledons.
About 100 spiral arteries pump blood into the cotyledons, providing a steady supply of oxygenated blood for the villi to bathe in.
Oxygen, glucose, and other molecules like immunoglobulins, hormones, and even certain toxins are able to move across the syncytiotrophoblast lining the villi wall, and then move across the endothelial cells lining the fetal capillaries.
Meanwhile, carbon dioxide makes the opposite journey, leaving the fetal capillaries and entering the maternal blood in the junctional zone.
As the fetus grows, so does the uterus and the placenta—the placenta covers about 15–30% of the uterine wall at any given time during development.
The placenta also thickens and by the time the fetus reaches full term, it’s about 20cm across, the size of a frisbee.
During the third stage of labor (after the baby is born), the placenta pulls away from the wall of the uterus, since it is no longer needed at that point, and it’s expelled from the body as afterbirth.
Umbilical Chord
During development, the fetus is connected to the placenta via the umbilical cord, a long, flexible stalk that has two small arteries and a large vein.
Deoxygenated fetal blood flows through the umbilical arteries to the placenta where it picks up oxygen and glucose while dropping off carbon dioxide.
Oxygenated blood then heads back towards the fetus’s heart through the umbilical vein.
When the baby is born the umbilical cord is no longer needed, so it’s cut off, leaving the navel or belly button.
The embryoblast has two layers called the epiblast, which contains the amniotic fluid, and the hypoblast, which contains the yolk sac filled with vitelline fluid that can nourish the embryo.
Cells from the epiblast layer start to differentiate into extraembryonic mesoderm cells, so-named because they are outside of the developing embryo.
These are some of the earliest mesoderm cells, and they start to form even while the embryoblast itself is a bilaminar disc.
These mesoderm cells line the inside of the cytotrophoblast and syncytiotrophoblast and form the chorion.
As development progresses, a space called the chorionic cavity develops between the embryoblast and the chorion, and these two structures are connected by a short band of extraembryonic mesoderm called the body stalk.
The body stalk contains the umbilical vessels and is the first of three structures that make up the umbilical cord.
In week 3 of development, the embryo folds in two directions.
In the longitudinal plane, there is a cranial and caudal fold, so that the embryo now looks less like a pancake and more like a little shrimp.
The folding process shapes part of the yolk sac into a gut tube, with the rest of the yolk sac remaining connected not at the cranial or caudal end, but just in the middle of the fetus.
The endoderm layer, which derives from the epiblast, forms the gut tube and soon divides into three parts—the foregut, the midgut, and the hindgut.
The midgut is open to the yolk sac via a connection called the vitelline duct, which is the second structure in the umbilical cord.
Around the same time, the hindgut grows a little outpocketing called an allantois, which grows towards the umbilical cord and drains the bladder.
The allantois is the third structure in the umbilical cord.
In week 4 of development, the amniotic cavity folds down and around the embryo.
The body stalk, the vitelline duct, and the allantois push together to form the umbilical cord at the site of the umbilical ring, a fibrous ring of tissue that develops on the abdominal wall of the fetus.
Between weeks 4–8, the cells lining the amniotic cavity (originally derived from the epiblast cells), start to generate a lot of amniotic fluid.
This causes the amnion to swell and take over most of the space in the chorionic cavity.
As the amnion expands like a big bubble, it folds in and covers the body stalk and vitelline duct, forming an outer membrane for the umbilical cord.
Now briefly, around week 6 of development, the fetal intestines grow so quickly that a part of the intestine squeezes through the umbilical ring into the umbilical cord.
This is called physiological umbilical herniation, meaning it’s a normal occurrence, and by the end of the third month of development the intestines withdraw completely back into the abdominal cavity.
So, looking at the umbilical cord in cross-section—there’s the outer layer of amnion, and then there’s the vitelline duct, which has its own arteries and veins and is connected to the yolk sac.
There’s also the allantois, and finally the two umbilical arteries and a single umbilical vein.
After the formation of the umbilical cord, the vitelline duct and yolk sac starts to shrink and eventually disappear.
In rare cases, the vitelline duct won’t regress all the way, and will leave behind a tiny remnant in the midgut—an outpouching of the intestines that’s called a Meckel’s diverticulum.
The allantois goes on to form the fetal urachus, a duct connecting the bladder to the yolk sac, and ultimately becomes the median umbilical ligament—the fibrous cord left behind when the urachus closes.
By the time of birth, all that remains within the umbilical cord is the umbilical vein, the two umbilical arteries, and a gelatinous substance called Wharton’s jelly that protects the umbilical vessels.
After birth the umbilical vein becomes the liver’s round ligament, and the umbilical arteries become the medial umbilical ligaments.
To keep it straight—think of the fact that there are two umbilical arteries, so all the umbilical arteries become medi-all ligaments, whereas there’s only an allantois, which turns into the medi-an ligament.
