Management of missed abortion in a patient with congenital cervical atresia.

Objective: To describe a patient with congenital cervical atresia who became pregnant through IVF and thawed transmyometrial ET and then experienced a missed abortion.

Design: Case report.

Setting: University hospital.

Premenstrual disappearance of aminopeptidase A in endometrial stromal cells around endometrial spiral arteries/arterioles during the decidual change.

Aminopeptidase A (APA, BP-1) is a membrane-bound zinc metallopeptidase that converts angiotensin II (AngII) into AngIII by selectively hydrolyzing the N-terminal aspartyl residue. AngII has been proposed as a candidate for the initial vasoconstrictor of endometrial spiral arteries/arterioles in the preliminary step of menstruation. In the late secretory phase, endometrial stromal cells (ESC) around the blood vessels begin to differentiate into decidual cells, and AngII has been reported to accumulate around such vessels.

Existence of placental leucine aminopeptidase/oxytocinase/insulin-regulated membrane aminopeptidase in human endometrial epithelial cells.

Human endometrial epithelial cells are known to express oxytocin receptors around the time of ovulation. Moreover, oxytocin (OT) and OT-induced prostaglandins appear to play a pivotal role in the switching of endometrial glands from the proliferative to the secretory phase. However, there have been few studies of oxytocinase (OTase), which is identical to placental leucine aminopeptidase (P-LAP)/insulin-regulated membrane aminopeptidase (IRAP).