Uterine Junctional Zone Evaluation on 3D Ultrasound and Its Relation to Major Adverse Obstetrical Outcomes in Assisted Reproductive Technology

During pregnancy, unique vascular changes occur, associated with decidualization of the maternal tissues in response to trophoblast invasion, first in the endometrium and subsequently in the myometrial JZ. The JZ broadly represents the inner third of the myometrium that, together with its overlying endometrium, is involved in placentation.

Defective deep placentation, defined by the absent or incomplete remodelling of the JZ segment of the spiral arteries, may be associated with a spectrum of obstetrical complications, ranging from late miscarriage and pre-term labour to fetal growth restriction and pre-eclampsia.

Thus, the primary site of vascular pathology in pregnancies lies not in the placenta or decidua but in the JZ. To understand how impaired remodelling of the myometrial JZ prior to conception may predispose to subsequent defective deep placentation, it is important to first describe the structural and functional changes in the JZ at the time of embryo implantation, and subsequently analyse the distinguishing features of defective deep placentation associated with different pregnancy disorders.

Thus, non-invasive assessment of the JZ prior to conception may turn out to be useful in identifying those women at risk of major obstetrical complications.

This project aims to evaluate the relationship between the characteristics of the ZJ in 3D ultrasound, and major adverse obstetrical outcomes in assisted reproductive technology (ART) treatments, namely in vitro fertilization cycles, intracytoplasmic sperm injection and frozen embryo transfer (FET).