Subinvolution

Abstract: Objective Heavy bleeding in the late postpartum has, in some cases, been attributed to subinvolution of the placental bed and enhanced myometrial vascularity (EMV) as seen on color Doppler imaging. The aim of this study was to investigate the incidence and spontaneous evolution of areas of enhanced vascularization over the whole thickness of the myometrium in asymptomatic women after uncomplicated term pregnancy. Methods This was a prospective descriptive study involving 93 consecutive women who were examined on day 3 (mean 2.6 ± 1.5) and at 6 weeks (mean 6.5 ± 1.3) after delivery following an uncomplicated term pregnancy. EMV was defined as the presence of marked flow over the full thickness of the myometrium reaching the uterine cavity. Doppler flow examination within the area of EMV and of both uterine arteries was performed. Results The mean patient age was 29.1 years and average parity was 1.7. The mean gestational age at delivery was 39.1 weeks. Areas of EMV were visualized in 50.5% of patients on day 3 vs. 3.9% at 6 weeks. None of the patients required therapy for bleeding problems. The mean pulsatility index and peak systolic velocity in the area of EMV on day 3 were 0.45 ± 0.30 and 0.37 ± 0.20 m/s, respectively. A consistent increase in vascular resistance and decrease in blood flow velocity was observed in both uterine arteries between day 3 and week 6. Conclusions Most areas of EMV reflect intermediate stages in the involution of the placental bed and do not cause abnormal postpartum bleeding. EVM is common in the puerperium, disappears spontaneously in the vast majority of cases, and does not warrant treatment if asymptomatic. Further research is needed to predict the rare cases in which subinvolution of the placental bed leads to heavy bleeding in the late postpartum. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.

Abstract: Context.—Subinvolution of the placental site is an anatomic cause of delayed postpartum uterine bleeding that may be underrecognized by general surgical pathologists. Objective.—To review the physiology of uteroplacental arterial development and normal postpartum involution, and to present the characteristic clinical and histopathologic features of subinvolution. Data Sources.—Literature review (MEDLINE via PubMed and Ovid) regarding the pathology and pathophysiology of placental site subinvolution. Review of the clinical and pathologic characteristics of our own institution's previously diagnosed cases of subinvolution from hysterectomy and endomyometrial curettage specimens. Conclusions.—Surgical pathologists must be aware of the cardinal histopathologic findings of subinvolution, and this diagnosis must be considered in every postpartum curettage or hysterectomy specimen presented to the surgical pathologist. Subinvolution of the placental site is an important diagnosis, as this process implie...

Abstract: Of 95 reproductive tracts from postpartum bitches, 20 had subinvolution of the placental sites. Grossly, the placental sites were hemorrhagic and about twice the size of normal sites at the same time after parturition. Microscopically, large masses of collagen, hemorrhage and dilated endometrial glands were in the endometrial sites. The myometrium was invaded in many areas by trophoblast-like cells from the endometrium. Variations in the size of placental sites in the same uterus were found in eight cases, and histological variations in the involution process in five. Invasion of the myometrium by trophoblast-like cells four days after parturition was seen in one bitch.