# Risk Factors and Pregnancy Outcomes of Twin Pregnancies With Gestational Diabetes Mellitus: A Comparison Based on Chorionicity

## TL;DR

This study finds that risk factors and outcomes for gestational diabetes in twin pregnancies differ depending on whether the twins share a placenta or not.

## Contribution

The study is the first to show that chorionicity affects GDM risk factors and outcomes in twin pregnancies.

## Key findings

- Advanced maternal age and preexisting hypertension are risk factors for GDM in both monochorionic and dichorionic pregnancies.
- Overweight, obesity, and other factors are only risk factors for GDM in dichorionic pregnancies.
- GDM increases the risk of preeclampsia in monochorionic pregnancies and preterm delivery in dichorionic pregnancies.

## Abstract

There is insufficient evidence to determine whether the risk factors and pregnancy outcomes associated with gestational diabetes mellitus (GDM) in twin pregnancies vary by chorionicity.

A retrospective cohort study was conducted among twin pregnancies. GDM was diagnosed using the IADPSG diagnostic criteria. Logistic regression and generalized estimation equation (GEE) models were used to identify the risk factors of GDM and its impact on pregnancy outcomes, stratified by monochorionic (MC) and dichorionic (DC) pregnancies.

Advanced maternal age (MC: aOR 2.18, 95% CI 1.25–3.81 and DC: aOR 1.32, 95% CI 1.06–1.67) and preexisting hypertension (MC: aOR 2.69, 95% CI 1.04–9.36 and DC: aOR 1.70, 95% CI 1.12–2.59) were risk factors for GDM regardless of chorionicity. Overweight (aOR 1.65, 95% CI 1.26–1.98), obesity (aOR 2.31, 95% CI 1.43–3.74), multiparity (aOR 1.43, 95% CI 1.10–1.88), assisted reproductive technology (ART) use (aOR 1.75, 95% CI 1.36–2.26), and polycystic ovary syndrome (PCOS) (aOR 1.98, 95% CI 1.37–4.12) were risk factors for GDM only in DC pregnancies. GDM was only associated with an increased risk of preeclampsia in MC pregnancies (aOR 1.29, 95% CI 1.04–2.26). GDM was associated with an increased risk of preterm delivery (PTD) at < 37 (aOR 1.13, 95% CI 1.05–1.34) and < 34 gestational weeks (aOR 1.15, 95% CI 1.07–1.75) in DC pregnancies.

The risk factors and pregnancy outcomes associated with GDM in twin pregnancies vary by chorionicity.