Cardio-metabolic risk and adverse pregnancy outcomes in the first trimester: findings from the Shenzhen birth cohort study

Abstract

Objective: To investigate the relationship between cardio-metabolic abnormalities in the first trimester and adverse pregnancy outcomes (APO). Methods: This cohort study recruited singleton pregnancies in the first trimester (6-13+6 weeks of gestation) from Shenzhen Maternal and Child Health Care Hospital between January 1, 2021, and October 31, 2022. Cardiometabolic markers, including body mass index (BMI), blood pressure, fasting plasma glucose (FPG), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG), were recorded during the first trimester. Incidence of APO, including gestational hypertension, preeclampsia, gestational diabetes mellitus, preterm birth, fetal growth restriction, small for gestational age infant, and placental abruption, was documented. Cardiovascular metabolic abnormalities in the first trimester were defined as meeting one or more of the following criteria: elevated BMI (BMI≥24 kg/m²), elevated TG (TG≥1.7 mmol/L), decreased HDL-C (HDL-C<1.0 mmol/L), elevated blood pressure (systolic pressure≥130 mmHg (1 mmHg=0.133 kPa) and/or diastolic pressure≥85 mmHg), elevated FPG (FPG≥5.6 mmol/L). Enrolled women were categorized into abnormal cardio-metabolic and normal cardio-metabolic groups. Poisson regression was employed to analyze the association between cardio-metabolic abnormalities in the first trimester and APO. Results: The study included 14 197 pregnant women with an age of (32.0±4.1) years. There were 8 139 women in the normal cardio-metabolic group and 6 058 women in the abnormal cardio-metabolic group. Women with cardio-metabolic disorders in the first trimester had a younger gestational age and higher incidence rates of preterm birth, gestational hypertension, preeclampsia, and gestational diabetes mellitus (all P<0.05). In multivariable Poisson regression, elevated BMI (RR=1.22, 95%CI 1.15-1.29), elevated FPG (RR=1.59, 95%CI 1.38-1.82), elevated TG (RR=1.22, 95%CI 1.13-1.31), and elevated blood pressure (RR=1.50, 95%CI 1.39-1.63) were independent risk factors for APO, while decreased HDL-C (RR=0.93, 95%CI 0.70-1.23) was not. Elevated blood pressure (RR=5.57, 95%CI 4.58-6.78), elevated BMI (RR=1.71, 95%CI 1.40-2.09), and elevated TG (RR=1.38, 95%CI 1.10-1.74) had the greatest impact on the risk of developing preeclampsia. Elevated FPG (RR=1.70, 95%CI 1.45-1.99) had the greatest impact on the risk of gestational diabetes. Conclusions: Elevated blood pressure, BMI, TG and FPG in the first trimester are closely related to APO.