The "Great Obstetrical Syndromes" are associated with disorders of deep placentation

Abstract

Defective deep placentation has been associated with a spectrum of complications of pregnancy including preeclampsia, intrauterine growth restriction, preterm labor, preterm premature rupture of membranes, late spontaneous abortion, and abruptio placentae. The disease of the placental vascular bed that underpins these complications is commonly investigated with targeted biopsies. In this review, we critically evaluate the biopsy technique to summarize the salient types of defective deep placentation, and propose criteria for the classification of defective deep placentation into 3 types based on the degree of restriction of remodeling and the presence of obstructive lesions in the myometrial segment of the spiral arteries.

Figure 1

Anatomy of maternal side of placenta. A. Opening of spiral artery at base of septum (left side). Brosens I, Dixon HG. The anatomy of the maternal side of the placenta. J Obstet Gynacol Br Cwth 1966, and Brosend Classification of defective deep placentation. Am J Obstet Gynecol 2010. B. Distribution of spiral artery openings with physiological changes (open circle) in the central area and without physiological changes (black circle) in the peripheral area of the placental bed. Note that the majority of openings are in clusters of 2 or 3 openings, frequently located at the base of a septum. Brosens. The uteroplacental vessels at term: the distribution and extent of physiological changes. Trophoblast Res 1988.

Figure 2

Spiral artery in the junctional zone myometrium showing: full transformation characterized by the loss of musculo-elastic structure and the presence of fibrinoid with cytotrophoblast (A), partial transformation (top and right) (B), absent transformation (note trophoblastic giant cells surrounding the artery) (C) obstructive lesions by acute atherosis and intimal hyperplasia and absence of transformation and (D) PAS staining, highlighting the fibrinoid in A and B. Brosens. Morphological changes in the utero-placental bed in pregnancy hyptertension. Clin Obstet Gynaecol 1977.

Figure 3

Uterus with placenta in situ from patient with severe hypertensive disease and intrauterine growth restriction. A. Spiral arteries in the centre of the placental bed show full transformation of the decidual and myometrial segments. B. Spiral arteries underlying infarcted areas of the placenta (X and Y) show acute atherosis and intimal hyperplasia in the non-transformed myometrial segment. Top: Brosens I, Renaer M. On the pathogenesis of placental infarcts in pre-eclampsia. J OBstet Gyncaec Br Cwth 1972. Bottom: Brosens. Classification of defective deep placentation. Am J Obstet Gynecol 2010.

Figure 4

A. Normal placental bed with full transformation of the myometrial spiral arteries except at the periphery of the placental bed B. Defective deep placentation is characterized by non-transformation of the myometrial spiral arteries reducing the central area with deep placentation.