The Association of Twin Chorionicity with Maternal Outcomes

Abstract

Objective Our objective was to investigate the association between maternal outcomes and twin chorionicity in a large, contemporary obstetric population. Study Design Retrospective cohort study conducted at a single, large tertiary care center. Prenatal and inpatient records for all individuals with twin gestations were reviewed from 2000 to 2016. Patients with monoamniotic twins, higher-order multiples reduced to twins, multiple sets of twins in the study period, or undetermined chorionicity were excluded. Patients with monochorionic twins were compared to those with dichorionic twins. The co-primary outcomes were gestational diabetes mellitus and hypertensive disorders of pregnancy. Secondary outcomes included cesarean delivery, preterm delivery, postpartum hemorrhage, and other maternal outcomes. Bivariable and multivariable analyses were performed to assess associations of chorionicity with maternal outcomes. Results Of the 2979 patients eligible for inclusion, 2627 (88.2%) had dichorionic twin gestations and 352 (11.8%) had monochorionic twin gestations. Patients with monochorionic twins were less likely to self-identify as non-Hispanic white and to have conceived via assisted reproductive technology, but were more likely to be publicly insured, multiparous, and have prenatal care with a maternal fetal medicine provider. Neither gestational diabetes mellitus (6.8% monochorionic vs 6.2% dichorionic, P = .74; adjusted odds ratio 1.06, 95% confidence interval 0.60-1.86) nor hypertensive disorders of pregnancy (21.9% monochorionic s 26.3% dichorionic, P = 0.09; adjusted odds ratio 0.99, 95% confidence interval, 0.71-1.38) differed by chorionicity. Of the secondary maternal outcomes, patients with monochorionic twins experienced a lower frequency of cesarean delivery (46.0% vs 61.8%, P < .001), which persisted after multivariable analyses (adjusted odds ratio 0.60, 95% confidence interval 0.46-0.80). There were no differences in preterm delivery, preterm premature rupture of membranes, hemorrhage, hysterectomy, or intrahepatic cholestasis of pregnancy. Conclusion The odds of gestational diabetes mellitus and hypertensive disorders of pregnancy do not appear to differ by twin chorionicity.

Maternal, Perinatal and Neonatal Outcomes of Triplet Pregnancies According to Chorionicity: Our 15-Year Experience in a Tertiary-Level Center

“…However, the authors are not aware of any publications that study the relationship between chorionicity and postpartum hemorrhage in triplet pregnancies. In twin pregnancies, chorionicity does not seem to affect the risk of developing postpartum hemorrhage [ 72 ].…”