HLTH 210 Chapter 28.4: Maternal Changes During Pregnancy/Birth

• School: University of Waterloo
• Department: Health Studies
• Course: HLTH 210
• Professor: Diane Williams

Document Summary

28. 4 maternal changes during pregnancy, labour and birth full term pregnancy = 270 days or 38. 5 weeks, often considered as 40. 5 weeks since the last menstrual period. Majority of fetal growth occurs in the 2nd and 3 trimester. Corpus luteum produces most hormones during weeks 7-12 progesterone stimulates decidual cell production of the endometrium which nourish the blastocyst before the placenta forms. The placenta takes over endocrine function around 12. Converts weak androgens secreted by adrenal glands to estrogen. Promote fetal viability by regulating progesterone and triggering fetal production of cortisol. Stimulate maternal uterine enlargement and mammary duct expansion. Increases elasticity of pelvic ligaments, makes room for growing fetus & helps dilate cervix. Progesterone: suppresses lh and fsh, also inhibits uterine contractions. Levels decrease in late gestation to allow uterine contractions for labour hcg: promotes survival of corpus luteum and stimulates male fetal gonads to secrete testosterone.