Prenatal Anatomy & Physiology Flashcards

The placenta is fully functional and takes over progesterone production from the corpus luteum at approximately which gestational week?

Answer: 8–10 weeks

The luteo-placental shift occurs around 8–10 weeks when the placenta assumes primary progesterone production.

Which ligament of the uterus is most directly involved in maintaining uterine anteversion?

Answer: Round ligament

The round ligaments pull the uterine fundus anteriorly, maintaining the normal anteverted position.

Compression of the inferior vena cava by the gravid uterus in supine position most directly causes:

Answer: Decreased venous return leading to maternal hypotension

Supine hypotensive syndrome occurs when uterine compression of the IVC reduces venous return, dropping cardiac output and blood pressure.

Which structure connects the fetal liver circulation to the inferior vena cava, bypassing hepatic sinusoids?

Answer: Ductus venosus

The ductus venosus channels oxygenated blood from the umbilical vein directly into the IVC, bypassing fetal hepatic processing.

Symphysis pubis dysfunction during pregnancy results primarily from:

Answer: Relaxin-mediated laxity of the fibrocartilaginous pubic joint

Relaxin increases mobility of the pubic symphysis beyond functional limits, causing pain and instability with weight-bearing movements.

The amniotic fluid volume peaks at approximately which gestational week?

Answer: 34–36 weeks

Amniotic fluid volume typically peaks around 34–36 weeks at approximately 800–1000 mL, then gradually decreases near term.

Which muscle is most responsible for pelvic floor weakness and prolapse risk during pregnancy due to the direct load of the uterus?

Answer: Levator ani

The levator ani forms the primary muscular floor of the pelvis and bears the greatest load from the gravid uterus.