Location and time of fertilization
Usually in ampulla of uterine tubes
Within 24hrs of ovulation
Time of implantation
Day 20-24 of menstrual cycle
3 weeks gestation
hCG
Human chorionic gonadotropin
Secreted by syncytiotrophoblasts
Bind LH receptors and promote progesterone secretion from corpus luteum
Detectable 9-11 days after LH surge
hCG other effects
Stimulates testes to secrete testosterone from Leydig cells (just like LH)
Promotes differentiation of cytotrophoblasts to syncytiotrophoblasts
Increase thyroid activity
Corpus Luteum secretion
Progesterone
17 hydroxyprogesterone - marker of corpus luteum b/c placenta cannot produce
Relaxin
Estradiol
hCG secretion change
hCG doubles every 2 days until peak @ 10 weeks
Pregnancy symptoms
Amenorrhea Vaginal bleeding/spotting Nausea w or w/out vomiting Elevation of temperature Fatigue Breast enlargement Increased urination with no dysuria
Pregnancy symptoms that are concering
Heavy bleeding
Nausea/vomiting after 10weeks gestation
Lightheadedness w/abnormal HR and rhythm
Dyspnea and other pulmonary symptoms
hPL and hPGH
hPlacental Lactogen: Secreted throughout, higher levels than hPGH
hPlacental Growth Hormone: Secreted later in gestation, shuts down maternal GH
Hormone involved with maternal insulin
hPL - decrease maternal insulin sensitivity
Increases lipolysis, decrease glucose uptake, increase gluconeogenesis
Glucose homeostasis in mother and fetus
Maternal: Insulin insensitivity, mobilize more free glucose for fetal use. fasting hypoglycemia, post prandial hyperglycemia, hyperinsulinemia
Fetus: Take glucose from mother
HPAdrenal Axis changes in pregnancy
Placenta produces CRH
Maternal hypercortisolism - Cushings levels, but progesterone can prevent other cushings symptoms
Fetus protected from high cortisol levels because of 11BHSD2: Cortisol –> Cortisone
Placental CRH difference from maternal
Cortisol has positive feedback on pCRH
Near term HPA axis change
Positive feedback from Cortisol increases - started by drop in CRH-BP
Less 11BHSD2 = increased fetal exposure to cortisol: Necessary for lung development and surfactant synthesis
Preterm labor steroids
Dexamethasone or betamethasone for babies born 23-34 weeks - hydrocortisone metabolized by 11BHSD2
Greater than 34 weeks not necessary
Less than 23 weeks lungs not developed enough for drug to work
Estriol
Major estrogen in pregnancy
Comes from 16a hydroxyDHEA-S in fetus liver
Travel to placenta and converted to estriol
Maternal-Placental-Fetal Unit
Placenta cannot make cholesterol - taken from mother
Placenta cannot make androgens (DHEA)
Fetus cannot make estrogens from androgens
Fetus and mom supply placenta with DHEA which gets converted to Estrogens
Progesterone functions during pregnancy
Increased secretions to nourish pregnancy
Decrease uterine contractility
Breast development
Alters cardiac and pulmonary parameters
Suppress immune function so fetus not rejected
Estrogen pregnancy functions
Increased uterine blood flow
Breast enlargement and ductal growth
Sink for weak androgens produced by fetus
Estrogen during labor
Increase uterine contraction and release of placental prostaglandins
Stimulates proteolytic enzymes in cervix for cervical dilation
Pregnancy and pituitary gland
Enlarges but no increase in blood flow
Hyperprolactinemia
Prolactin and pregnancy
Increase
Promotes alveolargenesis in breast
Milk synthesis post partum
Thyroid and pregnancy
Increase in TBG
Stimulation of TSHr by hCG
-Decrease TSH with increase FT4
Euthyroid hyperthyroxinemia
Pregnancy and renin angiotensin system
Increase in total body water
Estrogen drives activation of R-A-A system