(1013) Prevalence and Risk Factors of Gestational Hypertension and Preeclampsia in Twin Pregnancies: Population Based Study

To assess the prevalence and risk factors of gestational hypertension (GH) and preeclampsia (PE) in twin compared with singleton pregnancies.

Study Design:

Population-based study using CDC birth data from 2016-2020. Higher order pregnancies were excluded. A Chi-square test was performed to identify significant factors associated with GH/PE in twin versus singletons and within each group independently. Multivariable regression analyses were performed to assess risk factors that are significantly associated with GH/PE in twins and the risk of GH/PE in twin compared with singletons. P value < 0.01 was considered statistically significant.

Results:

Total of 17,972,300 singleton and 597,651 twin pregnancies were included. Following the multivariable regression, maternal age≥35 years, gestational and pre-pregnancy diabetes, non-Hispanic Black, overweight and class I/II/III obesity, excessive gestational weight gain (GWG), IVF, and prior preterm birth remained significantly associated with GH/PE in twins. However, multiparity, foreign-born, and W.I.C program reduced that risk. Factors that doubled the risk in twins were pre-pregnancy diabetes (OR 2.07 (1.93 – 2.21), P< 0.001), class III obesity (OR 2.59 (2.52 – 2.67), P< 0.001), and excessive GWG in the normal BMI group (OR 2.09 (2.02 – 2.16), P< 0.001). While smoking in 1^st, 2^nd, and 3^rd trimesters were not significant, periconception smoking was significantly associated with GH/PE in twins. Following adjustment for the significant factors, twins remained significantly associated with doubling the risk of GH/PE compared to singletons (OR 2.08 (2.06 – 2.09), P< 0.001).

Conclusion:

Pre-pregnancy diabetes, class III obesity, and excessive GWG doubled the risk of GH/PE in twins. Regardless of maternal demographics, obstetric history, and endocrine factors, twin pregnancy doubled the risk of GH/PE compared to singleton pregnancies. Smoking timing has significant relevance to the risk of GTH/PE in twin pregnancies. These factors can be used in risk prediction models to better counsel and manage these pregnancies.