Which of the following physiological events is specific to this time point in this patient's pregnancy? A 33-year-old woman tests positive on a home-pregnancy kit. She visits her gynecologist, and urinalysis is positive for a chorionic gonadotropin. Sonograms reveal a fetal crown-rump length consistent with 8 weeks' of pregnancy.
A. Blastocyst invasion B. Formation of the placenta C. Spiral artery remodeling D. Luteal-placental shift E. Syncytiotrophoblast hCG production
Luteal-placental shift-the luteal-placental shift occurs between 7-9 weeks of gestation. a fullyfunctional placenta begins secreting hormones, including estriol, during the lutealplacentalshift. a rise in estriol, the estrogen of pregnancy, indicates that the maternalfetal-placental unit is fully functional.distracter explanations:1) blastocyst invasion and formation of the placenta are complete by the end of the firstmonth of gestation.2) spiral artery remodeling and hcg production are ongoing events during the firsttrimester, but these events are not specific to 8 weeks of gestation.3) hcg levels start to decline during/after the luteal-placenta shift - the placenta startsproducing the large amounts of progesterone necessary to maintain pregnancy, andthese high levels of placental progesterone suppress the production of placental hcg.