Pregnancy, Adaptations, Parturition and Menopause

Question 1

What are symptoms and ways to test for a pregnancy

Answer 1

• 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)

Question 2

What is an obstetrician vs gynaecologist

Answer 2

• Obstetrician: Person who specialises in the care of women and the developing foetus
• Gynaecologist: Person who specialises in the female reproductive system

Question 3

What are anatomical maternal adaptations

Answer 3

• 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

Question 4

What are metabolic maternal adaptations

Answer 4

• 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

Question 5

What are physiological maternal adaptations

Answer 5

• 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

Question 6

What is unique about foetal circulation

Answer 6

• 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

Question 7

What are the 7 pregnancy hormones

Answer 7

• 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

Question 8

What are the main pregnancy structures

Answer 8

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

Question 9

What are 3 types of factors affecting foetal growth

Answer 9

• 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

Question 10

What occurs in the 2 types of twin pregnancies

Answer 10

• 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

Question 11

What is an ultrasound / sonogram

Answer 11

• 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

Question 12

What is amniocentesis

Answer 12

• 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

Question 13

What is CVS

Answer 13

• 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

Question 14

How can gestational diabetes mellitus affect the foetus

Answer 14

• 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)

Question 15

What is preeclampsia

Answer 15

• 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

Question 16

What are different supplements that are vital during pregnancy

Answer 16

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)

Question 17

What are the signs of labor

Answer 17

• 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

Question 18

What are the stages of labor

Answer 18

• 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

Question 19

What are the different types of birth

Answer 19

• 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)

Question 20

What is the APGAR scale

Answer 20

• 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)

Question 21

How is parturition regulated

Answer 21

• 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)

Question 22

What is the importance of foetal lung development / effect of first breath

Answer 22

• 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

Question 23

What are the differences between the male vs female pelvis

Answer 23

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)

Question 24

What is the difference between a miscarriage and a still birth

Answer 24

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

Question 25

What is menopause

Answer 25

• 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

Question 26

What are the hormones that are important during labor

Answer 26

• 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