Hypertension in dichorionic twin gestations: how is birthweight affected?

Objective: To examine the association between hypertension (HTN) and discordant or small for gestational age (SGA) birthweights among dichorionic twin pregnancies. Methods: Retrospective cohort of dichorionic twin pregnancies delivered at >= 24 0/7 weeks from 2002 to 2015. Women with HTN in pregnancy (gestational HTN or preeclampsia) and chronic HTN (cHTN) were compared to those with uncomplicated dichorionic pregnancies. Outcomes were any discordance (>= 20% difference within each twin pair), discordance with at least one twin also SGA (>= 20% discordance with at least one twin also SGA <10th percentile), and SGA alone of one or both twins (55th and510th percentile). Results: 474 Dichorionic pregnancies were identified. Women with HTN in pregnancy had an adjusted odds ratio (aOR) of 2.68 (95% CI 1.48-4.87) for any discordance and 2.94 (1.57-5.48) for discordance with at least one twin also SGA. These aORs for women with cHTN were 4.65 (1.39-15.52) and 4.37 (1.21-15.76), respectively. Significant differences were not observed for SGA alone of one or both twins. Conclusion: Among dichorionic pregnancies, both women with HTN in pregnancy and cHTN demonstrated increased odds of any discordant growth, as well as discordance with concurrent SGA of at least one twin. Odds of these outcomes were greatest with cHTN.