Association of dietary inflammatory index in the second trimester of pregnancy with birth weight discordance and postpartum complications in twin pregnancies

Objective: To explore the correlations among dietary inflammatory index (DII) in the second trimester of pregnancy, occurrence of birth weight discordance (BWD), and postpartum complications in twin pregnancies. Methods: Pregnant women who received prenatal screening at Guangzhou Women and Children Medical Center (Guangzhou, China) were enrolled. A questionnaire survey was conducted to collect data from pregnant women, including baseline information, childbearing history, dietary intake, and situation of the current pregnancy. Serum levels of inflammatory factors (C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-10 (IL-10), and interleukin-lβ (IL-lβ)) were measured by enzyme-linked immunosorbent assay (ELISA). DII in the second trimester was calculated based on dietary intake data. Univariate and multivariate logistic regression analyses were conducted to identify risk factors for BWD in twin pregnancies. The incidence of postpartum complications was compared between pregnant women with and without BWD. Results: The average DII values among 1568 pregnant women obeyed a normal distribution. According to twins' birth weight, pregnant women were divided into observation group (n=9) and control group (n=709). DII was significantly higher in the observation group than that in the control group (p < 0.05). The serum levels of CRP, TNF-α, and IL-6 significantly increased in the observation group compared with that in the control group (p < 0.05). The results of univariate and multivariate logistic regression analyses indicated that DII higher than 0, age above 30 years old, parity ≥ 2, gravidity ≥ 2, pre-pregnancy body mass index (BMI)≦25 kg/m 2, and opposite-sex twins were risk factors for BWD (p < 0.05). Pregnant women with a lower DII had a significantly reduced incidence of postpartum complications, including placental abruption, fetal distress, low-birth-weight babies, and macrosomia (p< 0. 05). Conclusion DII could influence fetal growth in twin pregnancies, and a higher DII value was associated with higher risks of placental abruption and fetal distress. Pregnant women should adhere to a healthy diet to mitigate the risk of adverse pregnancy outcomes that may arise from a pro-inflammatory diet.