If women who didn't take a prenatal care during the first trimester, we used the height and weight measured at premarital consultation.
Maternal body mass index (BMI, kg/m) was calculated using weight measurement at the first antenatal visit at primary healthcare examination during the first trimester of pregnancy and height measurement from FU1. Maternal smoking in pregnancy was recorded at the same antenatal visit.
In the first pregnancy trimester visit, we measured maternal height, and the mothers reported their prepregnancy weight and paternal weight and height.
Gestational anthropometric measurements were collected upon enrollment that corresponded to the second or third trimester of pregnancy, and included weight, height, MUAC, and TSF.
If fetal size (BPD) in early second trimester also differ according to maternal height, ultrasound dating may induce a biased estimate of EDD [ 31].
Gestational age was determined from a combination of maternal history (expected date of delivery, height of fundus, first trimester ultrasound) and the Ballard score, which was done by attending clinical staff.
In the multivariate model, the estimate for the primary outcome (composite morbidity) was adjusted for maternal country of birth (Nordic yes/no), age, BMI, height, smoking in the first trimester of pregnancy, parity, mode of delivery, PIH, and preeclampsia.
Fourth, since some of the participants were recruited beyond the first trimester, and pre-pregnancy body weight and height were self-reported by questionnaire, pre-pregnancy BMI might be underestimated.
Maternal characteristics included nationality, defined as Nordic (Sweden, Finland, Denmark, Norway, and Island) or non-Nordic, smoking habits during the first trimester of pregnancy, age, parity, prepregnancy weight (kg), height (m), and BMI.
Since the fundal height can be increased in the first trimester due to a twin pregnancy or myomas, the open techniques is recommended in all trimesters.
