Hypertensive disorders of pregnancy and adverse outcomes of twins

Abstract Background Hypertensive disorders of pregnancy (HDP) can significantly impact infant outcomes. However, research on the effects of HDP on twin pregnancies is limited and has not been well understood. Methods Data were collected from 22 medical centers across 12 provinces in China, spanning from January 2018 to December 2020. The primary variable of interest was HDP, and perinatal outcomes and neonatal complications were meticulously examined. Statistical analyses employed multivariable logistic regression, propensity score matching, and overlap weighting (OW). Results Out of a total of 6,307 twin pregnancies, 1,013 cases (16.1%) were diagnosed with HDP. HDP increased the likelihood of preterm birth (2.68 [2.27–3.15] OW). Specifically, HDP elevated the rates of early and late preterm births (1.29 [1.00-1.67] OW and 2.31 [2.00-2.68] OW, respectively), while reducing the likelihood of extremely preterm births (0.32 [0.12–0.77] OW). Additionally, HDP was associated with increased rates of low birth weight and small for gestational age (OW-OR [95%CI] of 1.54 [1.34–1.78] and 1.18 [1.00-1.42], respectively). Furthermore, it significantly heightened the likelihood of birth weight discordance (> 15%, > 20%, and > 25%). Among twin complications, HDP was linked to elevated rates of oxygen requirement (1.29 [1.07–1.56] OW), 1-minute Apgar scores < 7 (1.29 [1.07–1.56] OW), and NICU admissions (1.58 [1.32–1.90] OW). Stratified and sensitivity analyses reaffirmed the robustness of these findings. Conclusions HDP increases adverse outcomes in twins, both in terms of perinatal and complication risks. Therefore, careful monitoring and management are imperative for mothers diagnosed with HDP carrying twins to mitigate these adverse outcomes. Trial registration: NA