Placental pathology and hypertensive disorder of pregnancy in multiple gestation

Twin gestations have high prevalence of hypertensive disorders of pregnancy (HDP). The underlying placental pathology associated with HDP in twin pregnancies is not well established.

This is a retrospective cohort study in a single healthcare system. Patients with diamniotic twin gestation and placental pathology were included. Demographic and clinical information was abstracted.

All placentas were evaluated for the presence (in one or both placentas) of four pathologic categories. Among those with HDP, placental pathology was compared by delivery timing of <36 weeks and ≥ 36 weeks. Multivariable logistic regression was utilized to assess the independent association of placental histology in HDP vs no HDP and subsequently among those with HDP by early (<36 weeks) vs late (≥36 weeks) delivery.

A total of 456 patients were included, 151 of which had HDP (33%). Pregnancies with HDP had CI in 35.1%, MVM in 36.4%, FVM in 36.4% and AI in 24.5%. There was increased MVM among those with HDP (aOR MVM 1.60 95% CI 1.03, 2.46). Among pregnancies with HDP, MVM was increased at <36 weeks vs ≥ 36 weeks (56.1% vs 24.5%, aOR 4.80 (95% CI 2.23, 10.35) p < 0.011), whereas CI was less common (aOR 0.27, 95% CI 0.12, 0.63, p < 0.01).

MVM is more common in HDP, especially in those delivering <33 weeks than at term, and CI is more common in HDP delivering at term. Further work is needed in understanding the pathophysiology of HDP in twin gestation.