Abnormal maternal apolipoprotein levels during pregnancy are risk factors for preterm birth in women with dichorionic twin pregnancies: A retrospective study

Highlights•Serum Apo B levels increase gradually during pregnancy, while ApoA1 levels increase from the first to second trimester only and slightly decrease from the second to the third trimester in dichorionic twin-pregnant women.•Low ApoA1 levels and a high Apo B/ApoA1 ratio during the second and third trimesters are associated with a high incidence of preterm birth for overweight/obese dichorionic twin-pregnant women. While Apo B levels is not associated with preterm birth.•Low ApoA1 levels and a high Apo B/ApoA1 ratio predispose the pregnancy not only to iatrogenic preterm birth but also to spontaneous preterm birth in dichorionic twin-pregnant women.AbstractObjectiveIn singleton-pregnant women, abnormal maternal apolipoprotein levels have been confirmed as a risk factor for preterm birth. However, there are currently no studies on the relationship of the related research in twin-pregnant women.MethodsThis single-center retrospective study included 743 dichorionic twin-pregnant women who delivered between January 2019 and December 2020. Twins delivered before 37 weeks gestation were categorized as the preterm group, while those delivered at or after 37 weeks gestation were classified as the term group. Maternal serum apolipoprotein A1 (ApoA1) levels, apolipoprotein B (ApoB) levels, and the ApoB/ApoA1 ratio were measured in the first trimester(6–14 weeks), the second trimester(18–28 weeks) and the third trimester(after 28 weeks). We conducted SPSS analysis to evaluate the correlation between ApoA1 levels, ApoB levels, the ApoB/ApoA1 ratio and preterm birth.ResultsAmong the 743 included dichorionic twin-pregnant women, 53.57 % (398/743) delivered preterm. Compared with the term group, the ApoA1 levels in the third trimester were lower (p < 0.001), while the Apo B/ApoA1 ratio was higher in the second (p = 0.01) and third trimesters in the preterm group (p = 0.001). When preterm birth was categorized as iatrogenic and spontaneous preterm birth, the results were similar. In the analysis stratified by prepregnancy BMI, a higher risk of preterm birth was associated with low ApoA1 levels and a high Apo B/ApoA1 ratio in the second and third trimesters only among the subgroup of overweight/obese dichorionic twin-pregnant women.ConclusionsLow ApoA1 levels and a high Apo B/ApoA1 ratio during the second and third trimesters were associated with a high incidence of preterm birth for overweight/obese dichorionic twin-pregnant women.