Maternal Adaptations to Pregnancy Flashcards
Human placental lactogen (HPL)
- polypeptide, similar to GH and Prl
- rises steadily throughout pregnancy
- can also be positive with bronchogenic carcinoma, hepatoma, lymphoma and
pheochromocytoma - functions include lipolysis, inhibition of glu uptake, anti-insulin
- not required for successful pregnancy
Human Chorionic Gonadotropin (hCG)
- glycoprotein, 2 subunits, alpha is similar to FSH/LH/TSH, beta is specific
- increases with multiple gestations, erythroblastosis, hydatidiform mole,
choriocarcinoma - actions: prolongs life of corpus luteum, inc. steroid production; used as a dx test for pregnancy
The placental hormones
HPL, hCG, LHRH, TRH, E, P
Cervical changes during pregnancy
- Softening and cyanosis
- Increased vascularity
- Edema
- Hypertrophy and hyperplasia of glands
- Erosions
- Cervical mucus
- Histology
- Connective tissue
Chadwick’s sign
Violet blue color of the vaginal mucosa ⇒ presumptive sign of pregnancy
Uterine changes during pregnancy
- Weight - ~1,000g heavier
- Volume
- Type of uterine muscular growth - wall thins from ~10 to 5.5mm
- Stimulus for growth
- Uterine position changes
- Uterine contractions
- Uterine blood flow - inc. from about 100 to 600 ml/min
- Cervical changes
Ovaries/oviduct changes during pregnancy
The ovaries: • Ovulation • Corpus luteum • Relaxin • Luteoma • Decidual reaction • Engorgement of ovarian veins The oviducts: • Flattened epithelium • Decidual cells but no continuous decidual reaction
Maternal endocrine changes during pregnancy
- RAAS is much more active
- increased PTH, Vit D, Ca absorption; dec. total but normal ionized Ca, normal calcitonin
- thyroid enlarged but TSH/function normal, inc. TBG capacity, normal T3/T4, inc. BMR
- pituitary enlargement, GH is low around delivery and remains low; Prl inc. in preg, drops after delivery; oxytocin inc. with gestational age
- adrenal hormones increase throughout preganancy
Fetal endocrine changes during pregnancy
- PTH at 12-13wks, low till term; Ca falls postpartum, calcitonin normal, 25(OH)D normal, 1,25(OH)2D low at term, inc. first 48 hrs
- TSH normal at term, thyroid functions at 12-16wks; TBG capacity, T3/rT3 inc. at term, free T4 normal at term, T3 normal by 1st week
Metabolic changes in pregnancy
• Weight gain
• Protein metabolism - aa’s increase in fetus
• Carbohydrate metabolism - insulin resistance in mom
• Fat metabolism - fat consumed whenever possible, inc. FFAs
*Average weight gain is 11kg (24lbs) accounted for by the fetal tissues and increased maternal tissues (uterus, breast, blood, EVF, and fat)
Urinary tract changes during pregnancy
- kidneys increase in size by 1.5cm, inc. GFR, RBF, cre clearance, dec. BUN; glucosuria, proteinuria
- ureter dilates, elongates, dec. urine flow
- bladder inc. in size and blood vessel tortuosity, elevation of trigone, inc. pressure from uterus
CV, respiratory changes during pregnancy
- diaphragm is elevated at term, decreasing TLC/VC
- Heart displaced/rotated laterally, widely split S1 (85% with S3; 90% soft, mid-systolic flow murmur), atrial/ventricular extrasystoles
- CO inc. 4.5–>6L/min because of inc. SV, dec. TPR; theory = the fetus itself is like an AV fistula, inc. plasma volume, and hormonal changes
CV changes at delivery
- during labor: 30% increase in CO at first stage, then more in second stage; with anesthesia (pain relief) CO will dec.
- inc. in CO comes from inc. SV when pressure on IVC is relieved, and uterine contraction/autotransfusion
Hemodynamic changes during pregnancy
- dec. RBC life span, dec. O2 affinity
- increased reticulocytes, RCV, EPO; erythroid hyperplasia of BM–>requires more iron
- plasma volume inc. 45% (rapidly in 2nd trimester); Hct dec. 5-6%
- Hgb may dec but
Liver, Gallbladder, and Esophagus changes during pregnancy
Liver: • Alkaline phosphatase doubles • ↓ plasma albumin • ↓ cholinesterase activity • No change hepatic blood flow, bilirubin, or morphology Gall bladder: • Distension • Hypotonic • Thickening of bile Esophagus: • pressure ~15mmHg until week 36 (~3mmHg), then peaks postpartum (~25mmHg)
