Pregnancy, Conditions related to Pregnancy and Labor and Delivery Flashcards
Exam 1
Gametes
Ova and Sperm
How are gametes created?
Creation of gametes (ova and sperm) through meiosis
How many chromosomes per gamete?
Each gamete has 23 chromosomes (22 autosomes & 1 set sex chromosome).
When is sex of fetus determined?
Males: XY; Females – XX ( sex determined at fertilization)
How many oocytes are females born with?
Females are born with 1 to 2 million oocytes in their ovaries.
In males, when does spermatogenesis being?
In males, spermatogenesis does not begin until puberty.
What is formed during oogenesis?
In the female, one ovum and three polar bodies are formed through oogenesis.
What does one spermatogonium give rise to?
One spermatogonium gives rise to four spermatozoa.
Female Reproductive Hormones: HPO axis is:
H-P-O Axis: interactions between hypothalamus, pituitary (anterior), & ovaries –
What does the HPO axis do?
Regulates female reproductive cycle.
Female Reproductive Hormones: Low levels of progesterone and estrogen lead to what?
Low estrogen and progesterone levels stimulates hypothalamus to produce gonadotropin-releasing hormone (GnRH).
GnRH causes the anterior pituitary to release:
GnRH causes the anterior pituitary to release:
Follicle-stimulating hormone (FSH) and
Luteinizing hormone (LH).
Follicle-stimulating hormone
FSH - responsible for maturation of ovarian follicles to release eggs for fertilization.
When do levels of LH peak?
LH levels peak @ approximately 14 days before menses - causes ovulation
Two phases of the ovarian cycle?
- Follicular phase
- Luteal phase
Follicular phase (when is it and how long)
(day 1 through ovulation, approximately days ~10 to 14 ( in a 28-day cycle)
What occurs during the follicle phase?
Primordial follicle matures under influence of follicle stimulating hormone(FSH) and luteinizing hormone (LH) until ovulation
What kind of phase is the follicular phase?
Variable phase
Ovulation- how long is it?
Ovulation (day ~14 of a 28-day cycle)- occurs due to surge in LH
Luteal phase- how long is it?
Luteal phase (day ~15 through day 28 of a 28-day cycle)
What occurs during the luteal phase?
Ovum leaves follicle
Corpus luteum – develops DT LH, produces progesterone
Estrogen production diminished
What kind of phase is the luteal phase?
Fixed phase
After ovulation, what is the ovarian follicle called?
After ovulation, ovarian follicle is called a corpus luteum.
What are the phases of the Menstrual (Endometrial or Uterine) Cycle?
- Menstrual phase (day 1-6)
- Proliferative phase(day 7-14)
- Secretory phase (day 15-26)
- Ischemic phase (day 27-28)
Menstrual phase (day 1-6)
Endometrium shed; estrogen low; cervical mucus scant, viscous opaque
Proliferative phase(day 7-14)
Endometrium and myometrium thickness increases
Estrogen peaks prior to ovulation
(Temperature increases up to 1 degree)
Mittelschmerz – sharp pain on side of ovulation
Secretory phase (day 15-26)
Estrogen drops, progesterone rises, vascularity increased, readies for implantation
Ischemic phase (day 27-28)
Hormone levels both drop; spiral arteries vasoconstrict; blood vessels rupture, blood to stromal cells, preparing to be shed
After ovulation, how long are ova available for fertilization?
After ovulation, ova are viable for fertilization for 6 to max 24 hours.
Sperm may be capable of fertilizing an egg for how long?
Sperm may be capable of fertilizing an egg for as long as 5 days.
Where does fertilization occur?
Fertilization generally occurs in the fallopian tube (ampulla).
Cortical reaction
Once egg is fertilized- other sperm are blocked from penetration through process called a cortical reaction.
After conception, what happens to sperm and egg chromosomes?
After conception, the 23 chromosomes from sperm +23 chromosomes from egg, create a diploid zygote with 46 chromosomes.
After diploid zygote formation, what occurs?
1.Doubling of cells
- Morula (day 3 to 4)
- Blastocyst (day 5-7)
Confirming Pregnancy: What is produced at the time of pregnancy?
Human chorionic gonadotrophin (hCG) hormone-produced at the time of implantation.
Confirming pregnancy: How does hCG increase?
hCG doubles approximately every 48 to 72 hours.
What do at home pregnancy tests do?
Home pregnancy tests detect hCG in the urine.
False negatives can occur in pregnancy test, what should a woman do?
If a woman thinks she is pregnant, but urine test was negative, she should repeat the test in 3 to 7 days.
Signs and Symptoms of Pregnancy-Confirming Pregnancy: Presumptive symptoms
Women describes symptoms
Fatigue
(12 weeks)
Breast tenderness
(3 to 4 weeks)
Nausea and vomiting
(4 to 14 weeks)
Amenorrhea
(4 weeks)
Urinary frequency
(6 to 12 weeks)
Hyperpigmentation of skin
(16 weeks)
Fetal movements (quickening)
(16 to 20 weeks)
Uterine enlargement
(7 to 12 weeks)
Breast enlargement
(6 weeks)
Signs and Symptoms of Pregnancy-Confirming Pregnancy: Probable signs of pregnancy
Slide 13
Positive signs of pregnancy
Ultrasound verification of embryo or fetus
(4 to 6 weeks)
Fetal movement felt by experienced clinician
(20 weeks)
Auscultation of fetal heart tones via Doppler
(10 to 12 weeks)
Intrauterine Development- Preembryonic stage:
Fertilized ovum becomes a morula and then blastocyst before entering the uterus.
Intrauterine Development- Embryonic stage (weeks 2-8)
Implantation by the end of week 2.
Neural tube fuses at the center and tubular heart begins to beat in week 3.
Respiratory and digestive tracts begin to form and the neural tube fusion is complete in week 4.
Limb buds appear in week 5.
In week 6, the heart is in its final form.
In week 8, the first brain waves are detectable.
Intrauterine Development- Embryonic stage (week 2)
Implantation by the end of week 2.
Intrauterine Development- Embryonic stage (week 3)
Neural tube fuses at the center and tubular heart begins to beat in week 3.
Intrauterine Development- Embryonic stage (week 4)
Respiratory and digestive tracts begin to form and the neural tube fusion is complete in week 4.
Intrauterine Development- Embryonic stage (week 5)
Limb buds appear in week 5.
Intrauterine Development- Embryonic stage (week 6)
In week 6, the heart is in its final form.
Intrauterine Development- Embryonic stage (week 8)
In week 8, the first brain waves are detectable.
Intrauterine Development 9-24 weeks: (week 9-12)
In weeks 9-12, fetal movements begins,
Kidneys begin to function
genitalia fully differentiated
Intrauterine Development 9-24 weeks: (week 13-16)
In weeks 13 to 16, oogenesis established in females, blood vessels visible under the skin, ridges that will form in the finger, hand, foot and toe prints are present
Intrauterine Development 9-24 weeks: (week 20)
By the 20th week, fetal swallowing is present and insulin production begins
Lanugo and vernix cover the body
Intrauterine Development 9-24 weeks: (week 24)
Lungs begin to form surfactant
Intrauterine Development 28-38 weeks. (28 weeks)
By the 28th week, testes descend in males, the fetus often moves to a head down position, and blood is produced in the bone marrow.
Intrauterine Development 28-38 weeks. (29-34 weeks)
In weeks 29 to 34, subcutaneous fat deposits begin and the fetal heart rate variability is more pronounced due to central nervous system maturity.
Intrauterine Development 28-38 weeks. (33-38 weeks)
In weeks 33 to 38, visual acuity is 20/600, vernix occurs only in skin creases, and lanugo only on upper back and shoulders. The lungs and central nervous system mature while the fetus continues to grow and gain weight.
Placenta
A circulatory interface between the mother and the embryo/fetus.
Where does the placenta form?
Forms at the site of blastocyst implantation.
What does the placenta attach with? Where does it expand over?
Attaches with finger-like projections known as chorionic villi.
Expands over the inner surface of the uterus until about 20 weeks’ gestation.
Two sides of the placenta:
Fetal surface is smooth and translucent, called “shiny Schultze”.
side has red, meaty appearance, called “dirty Duncan”.
Three primary purposes of the placenta
Serves three primary functions:
- circulation(gas exchange),
- waste excretion, and
- hormone production.
How is the placenta connected to the fetus?
Connected to fetus via umbilical cord
What does the umbilical cord contain?
Contains one large vein that carries oxygenated blood to the embryo/fetus and two smaller arteries that carries deoxygenated blood to the placenta.
What is the umbilical cord covered in?
The umbilical cord is covered in Wharton jelly, which helps support and protect vessels. (prevents compression)
Why would the umbilical cord appear twisted?
Often appears twisted, likely from fetal movement.
What does the umbilical cord serve as?
Serves as a conduit for blood traveling to and from the embryo/fetus
Amniotic fluid
Helps maintain a constant body temperature for the fetus (1º warmer than mother)
Cushions the fetus from trauma
Allows the umbilical cord to be relatively free of compression
Promotes fetal movement to enhance musculoskeletal development
What does the amniotic fluid permit?
Permits symmetric growth and development
What is the amniotic fluid made from?
Made from fluid from maternal and fetal blood and later fetal urine
How much amniotic fluid is present at birth?
1,000-1,200 ml at birth
Where is the umbilical cord formed?
Formed from the amnion
What is considered the lifeline from the mother to the growing embryo?
Lifeline from the mother to the growing embryo
At term, how long is the umbilical cord?
At term, the average umbilical cord is 22-in (55 cm) long and about 1-in wide
Endocrine System Changes: How long does the gestational parent supply thyroid hormones to the fetus?
Gestational parent supplies thyroid hormones to the fetus until the 12th week of pregnancy when the fetus can produce on its own.
What type of hormones is critical to fetal neurological development?
Thyroid hormones is critical to fetal neurological development.
How is thyroid hormone during pregnancy?
Thyroid hormones often increase during pregnancy.
What needs increase steadily during pregnancy? When?
Insulin needs increase steadily beginning in the second half of pregnancy.
What type of parents develop gestational diabetes?
Patients who are pregnant whose pancreases cannot keep up with increased insulin demands develop gestational diabetes.
What increases in the second trimester of pregnancy? What does this increase promote?
Cortisol levels increase in the second trimester of pregnancy and may promote lung and neurological development.
What is oxytoxin produced by?
Oxytocin is produced by the posterior pituitary and has a role in producing contractions, postpartum uterine contraction, and milk ejection.