Objective The authors evaluated the differences in twin preterm birth rates in the setting of pre-eclampsia by gestational age at birth and between different racial/ethnic groups.

Abstract PM.50

Study Design This is a retrospective cohort study of women pregnant with twins delivered in California in 2006, separated into two cohorts: pre-eclampsia and no pre-eclampsia. Outcome data were tabulated by four gestational age groups (24–27, 28–31, 32–36 and 37–42 weeks) and stratified by race/ethnicity.

Results Women with pre-eclampsia are at a significantly increased risk of delivering at 32–36 weeks as compared to women without pre-eclampsia (p<0.001): 61.4% vs 45.5%. Preterm delivery rates in the setting of pre-eclampsia varied by race/ethnicity and were significantly higher in Caucasians and lower in Asians (p<0.001): 71.0% in Caucasians, 66.7% in African Americans, 67.0% in Latinas and 63.6% in Asians.

Conclusion Women with twins who also have pre-eclampsia have 15.9% more preterm births. Although African American women without pre-eclampsia experience higher preterm birth rates than other racial/ethnic groups, this effect is not seen in African American women with pre-eclampsia. In the setting of pre-eclampsia, Caucasians have more and Asians have fewer preterm births than other racial/ethnic groups.