Pregnancy, Adaptations, Parturition and Menopause Flashcards
What are symptoms and ways to test for a pregnancy
- Symptoms: Missed menstrual period, excessive tenderness in breasts, fatigue, change in appetite, morning sickness (first trimester, avoid teratogens / toxins, increase in hCG), spotting / irregular menstrual flow
- Pregnancy Test: Measure hCG (presence as early as 2 weeks, produced by corpus luteum and later placenta), 97% accuracy
- Blood Test: Quantitative blood test (measures exact concentration of hCG) and qualitative (yes or no)
What is an obstetrician vs gynaecologist
- Obstetrician: Person who specialises in the care of women and the developing foetus
- Gynaecologist: Person who specialises in the female reproductive system
What are anatomical maternal adaptations
- Reproductive organs become engorged with blood
- Chadwick’s sign (vagina develops purplish hue)
- Breasts enlarge and areolae darken
- Uterus expands, occupying most of abdominal cavity
- Lordosis occurs with change in centre of gravity
- Placenta secretes relaxin, causes pelvic ligaments and pubic symphysis to relax (ease birth passage)
- Weight gain of around 10-13kg
What are metabolic maternal adaptations
- Placental hormones, increased appetite and energy requirements
- Human Placental Lactogen (HPL): Stimulates maturation of breasts, foetal growth, glucose sparing in mother (may cause gestational diabetes mellitus)
- PTH / Vitamin D: High throughout pregnancy, ensure adequate Ca for foetal bone mineralisation
What are physiological maternal adaptations
- Morning sickness
- Frequent urgent urination / stress incontinence occur (bladder compressed)
- Oestrogen’s may cause nasal edema and congestion
- BV increases 25-40%, safeguard against blood loss during childbirth
- Q rises (35-40%), proper greater volume around body
- Venous return from lower limbs may be impaired, result in varicose veins
- Hormones maintain pregnancy, prepare for delivery and breast feeding
What is unique about foetal circulation
- First BC arise in yolk sac, umbilical cord connects embryo to placenta
- Ductus Venosus: Umbilical vein drains into ductus venosus, empties into inferior vena cava, bypass liver
- Foramen Ovale: Opening in interatrial septum, bypasses pulmonary circulation
- Ductus Arteriosus: Pulmonary trunk drains into ductus arteriosus which drains into aorta, bypasses pulmonary circulation, shunts blood away from non-functional lungs
What are the 7 pregnancy hormones
- hCG: Maintains corpus luteum, high in 1st trimester dramatic fall in 2nd
- Progesterone: Maintains uterine lining, inhibits uterine contraction, increasing in 2nd, highest in 3rd
- Oestrogen: Maintains uterine lining, stimulates mammary glands, increasing in 2nd, highest in 3rd
- Placental Lactogen: Stimulates mammary glands and supplies energy to foetus
- Parathyroid Hormone RP: Increases blood calcium
- Relaxin: Softens cervix and weakens pubic symphysis, preparation for delivery
- Corticotropin RH: Increases heart rate, blood pressure, blood glucose, stimulates partition
What are the main pregnancy structures
Corpus Luteum:
- Endocrine gland, maintain pregnancy, -ve feedback to hyp and AP
- Secretes progesterone inhibits further development of antral follicles
- Taken over by placenta after 3 months
Placenta:
- Established 5 weeks after implantation
- Source of oestrogen, progesterone and peptide hormones after 8 weeks of pregnancy, endocrine gland
- Supplies foetus with O2, CO2, nutrients, removes wastes
- Acts as lungs, kidneys, GIT and skin
What are 3 types of factors affecting foetal growth
- Foetal: Genetic makeup (~40%), sex, production of hormones and GF (thyroxine, insulin)
- Placental: Size, SA for diffusion, transport processes, hormone production, umbilical BF
- Maternal: Maternal age / size, uterine blood flow, nutrition, diseases diabetes, infections), drugs
What occurs in the 2 types of twin pregnancies
- Monozygotic: Identical, one zygote, same chromosomes, same sex
- Dizygotic: Fraternal, two fertilised ova, different chromosomes, same sex or opposite sex, separate amniotic sacs, umbilical cords and placentas
- Siamese: Identical twins joined in utero, rare live births, share single chorion, placenta and amniotic sac
What is an ultrasound / sonogram
- High-frequency sound waves
- Image developing baby and mother’s reproductive organs
- Detect sex, foetal heartbeat, estimate due date, check for multiple pregnancies
- Diagnose ectopic pregnancies, detect anatomical anomalies
What is amniocentesis
- Amniotic fluid removed via a fine needle inserted into uterus through abdomen
- 15-18th week, contains foetal cells and other substances
- Assess foetal health in particular birth defects including down syndrome, sickle cell disease, cystic fibrosis, muscular dystrophy, tay-sachs
- Small risk of miscarriage (1:200-400), injury to baby / mother, infection, preterm labour
- Offered to women with abnormal ultrasound / lab screens, family history of birth defects
What is CVS
- Chorionic villus sampling
- Biopsy is taken of the villi in placenta (trans-cervical or trans-abdominal)
- 10-14 week (early)
- Tests for sickle cell anaemia, haemophilia
- Risk of miscarriage is 1:100
How can gestational diabetes mellitus affect the foetus
- Abnormally raised BG levels around 24th - 28th week
- 3-7% gestational diabetes
- Hormones from placenta cause cells to become insulin resistant
- Does not affect mother after baby is born but have increased risk of type 2 diabetes
- Baby will not be born with diabetes, usually no symptoms but baby often larger
- All women screened for gestational diabetes at 24 -28 week routine check up, glucose tolerance test (ingestion of 75g glucose drink after fasting)
What is preeclampsia
- Dangerous complication
- Deterioration of placenta and insufficient placental blood supply, foetus starved of oxygen
- Treated with Mg sulphate
- Marked by high BP, failing kidneys (protein in urine), swelling in feet, legs, and hands
- Late in pregnancy, most often in first-timers, teens and women over 40, 1:10 pregnant women
- Precursor to more serious, potentially fatal eclampsia (seizures & coma)
- Less then 1:100 women withpreeclampsia developeclampsia
What are different supplements that are vital during pregnancy
Exercise / Diet:
- Increases health of baby, proper birth weight
- Decrease birth defects
- Avoid contact sports
Folate / Folic Acid:
- B group water-soluble vitamin
- Folate: Naturally in food
- Folic Acid: Added supplements
- Aids development of NS, prevents neural tube defects
Iron:
- Critical for O2 transport and healthy growth / development of foetus / placenta
- Anaemia associated with preterm delivery, depression and infant anaemia
Vitamin D:
- Immune function, bone health, cell division
- Lack of vitD associated with multiple sclerosis (autoimmune)
What are the signs of labor
- Mucous Plug: In the cervix, which acts as a seal during pregnancy, is passed as a blood stained or brownish discharge
- Contractions: Coordinated muscular contractions are generated in the upper part of the uterus, the fundus, helps to gradually open, or dilate, the cervix
- Water Breaks: Amniotic sac surrounding the baby ruptures, or breaks, allowing colourless amniotic fluid to pass out through the birth canal
- Hormonal Trigger: To initiate parturition in humans has not been identified, foetal origins
What are the stages of labor
- Dilation of Cervix: Longest stage of labor, cervical opening enlarges eight to ten centimetres
- Delivery of Baby: Begins when cervix is completely dilated, baby moves farther down the birth canal, usually head first, mother pushes, and the muscles in the uterus contract to push the baby out
- Baby’s head will be visible (crowning), ends with the delivery of the baby
- Delivery of Placenta: Expulsion of the afterbirth = placenta is expelled after delivery, if this does not occur naturally the physician removes it
What are the different types of birth
- Natural: Delivery of a baby without drugs or surgery
- Induced Labor: Stimulation of uterine contractions before they occur spontaneously
- Breech: When baby delivered either foot first or buttocks first
- C Section: Surgical incision made through abdomen and uterus to deliver baby
- Episiotomy: Incision of perineum, help with crowning, prevent muscles from tearing
- Vacuum Extraction: Assist mother, cup on baby’s head with slight suction
- Forceps: To guide baby’s head out of birth canal
- Epidural: Local anaesthetic injected at lumbar region to the space around spinal nerve, L2/3 or L3/4 space, 4-5cm dilated with regular contractions (may slow down contractions)
What is the APGAR scale
- Assessment test of newborn on a scale of 1-10, 7 or higher (good condition), 4-6 (assistance), <4 (life saving techniques)
- Activity: Muscle tone, absent (0), fixed arms and legs (1) and active (2)
- Pulse: Absent (0), below 100 bpm (1) and over 100 bpm (2)
- Grimace: Reflex irritability, floppy (0), minimal response to stimulation (1) and prompt response to stimulation (2)
- Appearance: Skin colour, blue / pale (0), pink body blue extremities (1) and pink (2)
- Respiration: Absent (0), slow and irregular (1) and vigorous cry (2)
How is parturition regulated
- Increased levels of Corticotropin Releasing Hormone (CRH), stimulates foetal pituitary to release ACTH (adrenocorticotropic hormone), stimulates mature foetal adrenal glands to release
- Cortisol: Stimulates foetal lung development, production of surfactant, ready to breath air, stimulates PG synthesis
DHEA: - Dehydroepiandro-sterone sulphate
- Produced by the adrenal cortex, converted to oestrogen in placenta
- Decrease in progesterone / oestrogen ratio
- Increased gap junctions in myometrium (prepared for contraction)
- Increased oxytocin receptors (uterus can respond to oxytocin)
- Increased prostaglandin production (causes cervical ripening / uterine contractions)
What is the importance of foetal lung development / effect of first breath
- 15-25 weeks (terminal bronchiole)
- 26 onwards (primitive alveoli)
- After birth (mature alveoli), foetal survival from 24 weeks
- First breath decreases the resistance in pulmonary vasculature
- Pressure in left atrium increases relative to pressure in right atrium
- Closure of foramen ovale (fossa ovalis), closure of the ductus venosus and ductus arteriosus
What are the differences between the male vs female pelvis
Male:
- Tilted less far forward, adapted for support of heavier build / stronger muscles
- Cavity of true pelvis is narrow and deep
- Heavier, thicker and prominently marked bones
- Acetabula are larger and closer together, pubic arch / angle is more acute (50-60)
Female:
- Tilted forwards, adapted for childbearing
- True pelvis defines the birth canal
- Cavity of true pelvis is broad, shallow and has a greater capacity
- Thinner, lighter and smoother bones
- Acetabula are smaller and farther apart, pubic arch / angle is broader and more rounded (80-90)
What is the difference between a miscarriage and a still birth
Miscarriage:
- Loss of a foetus before 20th week, spontaneous abortion
- Bleeding which progresses from light to heavy, severe cramps, abdominal pain, fever, weakness, back pain
Still Birth:
- Death of a baby during pregnancy after 20 weeks of but before delivery, 1/200
- Possible causes include high BP, diabetes, blood clotting problem, infection of mother / foetus, placental abruption (tearing away from uterus too soon), umbilical cord twisting, birth defect / slowed growth
What is menopause
- When menses have ceased for an entire year, 50-55 years, depletion of ovarian follicles / ova
- Declining oestrogen cause atrophy of reproductive organs / breasts, irritability and depression, hot flushes (skin BV = vasodilation), thinning of skin / bone, high blood cholesterol levels and falling HDL
- Hormone supplements have been associated with heart disease, breast cancer, stroke, dementia
What are the hormones that are important during labor
- Progesterone: Maintains pregnancy, relaxation of uterine muscle, suppresses spontaneous contractions, down-regulates oxytocin receptors, inhibits formation of gap junctions myometrium
- Oestrogen’s: Labor, stimulate myometrial contractions, up-regulates oxytocin receptors, stimulates formation of gap junctions myometrium, preps uterus for coordinated contractions
- Prostaglandins: Stimulate myometrial contractions
- Oxytocin: Strongest stimulator of uterine contractions, stimulates placenta to make prostaglandins which stimulates more vigorous contractions, positive feedback loop of oxytocin
