Predictive variables
Maternal age was defined as age in years at the time of stillbirth and
live birth, respectively. Maternal weight (in kg) was obtained at first
visit. BMI was grouped as underweight (≤18.5 kg/m2),
normal weight (18.6-24.9 kg/m2), pre-obesity (25-29.9
kg/m2), Obesity Class I (30-34.9
kg/m2), Obesity Class II (35-39.9
kg/m2) and Obesity Class III (≥40
kg/m2). Ethnicity was self-reported by the pregnant
woman at first visit and categorized into white, black, South Asian,
East Asian and mixed. Smoking was defined as current smoker or
non-smoker at antenatal booking or time of stillbirth. Gravidity was
defined as the number of current pregnancy. Parity was defined as the
number of previous deliveries (including stillbirths) above
24+0 gestational weeks or with a fetal weight of or
above 500g. Medical and obstetric history including type 1 and 2
diabetes and respective treatment (diet, insulin, metformin), chronic
hypertension, SLE, APS and previous pre-eclampsia were manually
retrieved from the women’s medical records.