Long-term risk for maternal cardiovascular morbidities in twin pregnancies complicated with gestational diabetes mellitus - a retrospective cohort study.

BACKGROUND

Gestational diabetes mellitus (GDM) results in an increased risk for maternal and neonatal complications in singletons. In twin pregnancies, however, scarce data exist regarding its implications.

OBJECTIVE

To investigate whether a diagnosis of GDM in twin gestation poses a risk for subsequent maternal long-term cardiovascular morbidity.

STUDY DESIGN

A population-based cohort study was conducted, comparing the incidence of cardiovascular morbidity within a group of women with and without a diagnosis of GDM who delivered twins in a tertiary medical center, between the years 1991 and 2014. Mothers with pregestational diabetes mellitus, triplet or higher-order multiples, patients lacking prenatal care, patients with known cardiovascular morbidities prior to or during the current pregnancy and fetal malformations or/and chromosomal abnormalities were excluded. Kaplan-Meier's survival curve was used to estimate the cumulative incidence of cardiovascular-related hospitalizations, and a Cox proportional hazards model was used to estimate the adjusted HRs for cardiovascular morbidity.

RESULTS

Of 4256 twin deliveries that met the inclusion criteria, 336 (7.9%) occurred in patients that were diagnosed with GDM. During a follow-up period of more than 10 years, with a median of 3431 (0-9172) days in total, patients with GDM had higher rates of simple cardiovascular events as compared to women without diagnosis of GDM (incidence = 7, 2.1%. OR = 2.7, 95% confidence interval (CI) 1.17-6.12,  = .03). Total cardiovascular hospitalizations were comparable between the groups. There was no difference between the two groups in the rate of complex cardiovascular events, noninvasive or invasive cardiac diagnostic procedures. In a Cox proportional hazards model, which is adjusted for maternal age, ethnicity, hypertensive disorders, and fertility treatments, GDM in twin pregnancies was not found to be associated with long-term cardiovascular morbidity (adjusted HR 1.41, 95% CI 0.77-2.58,  = .26).

CONCLUSIONS

While GDM during twin pregnancy might be associated with long-term maternal simple cardiovascular events, the complex, as well as the total morbidities, are comparable to patients without GDM.