Adverse pregnancy outcomes
All women were under carefully medical surveillance. Once complications occurred, they would receive treatment and the pregnancy outcomes would be followed up until after delivery. The adverse pregnancy outcomes were described as follows: PE was defined as a new onset of hypertension (systolic blood pressure ≥ 140mmHg, diastolic blood pressure ≥90mmHg on at least two measurements 4 hours apart in a previously normotensive woman), with one of the following at or after 20 weeks of gestation:1. Proteinuria (primarily defined as a protein concentration of ≥0.3g in 24 hours; i.e. ≥30 mg/mol protein: creatinine ratio; or≥2 + dipstick);2. Evidence of other maternal organ dysfunction; liver involvement with or without right upper quadrant or epigastric abdominal pain, neurological complications; or hematological complications; or 3.uteroplacental dysfunction[13]. GDM was diagnosed after all women underwent a 75-g oral glucose tolerance test between 24 and 28 weeks of pregnancy, we also applied IADPSG criteria (one or more fasting, 1-h, or 2-h plasma glucose concentrations equal to or greater than threshold values of 5.1, 10.0, or 8.5 mmol/L, respectively) to diagnose GDM[14]. Early Preterm delivery, defined by a gestational age before 34 weeks. A newborn was considered SGA when it was smaller than the estimated 10th percentile for the baby’s gender and gestational age[15]. Postpartum hemorrhage was defined as blood loss ≥500ml after vaginal delivery or ≥1000ml after cesarean delivery[16].