Information on measured AVD, maternal age, smoking status in early pregnancy, ethnicity, measured maternal weight and maternal height in early pregnancy was extracted from the digitalized medical records for every participant and manually registered in an anonymous research database. Gestational weight gain was defined as the difference between the registered weight in kilograms (kg) at the first antenatal visit to the antenatal care center, and the registered weight in term pregnancy at the delivery ward. If there was no registered weight at the delivery ward, the last registered weight at the antenatal care center (between gestational week 37-42) was used to calculate gestational weight gain.