Table 1.

Overview of demographics and pregnancy outcomes with their definitions

	Variable	Definition
Lifestyle Behaviours (Self-reported in the first trimester)	Body mass index	Kg/m2
	Underweight	<18.5 kg/m2
	Normal weight	18.5 - 25 kg/m2
	Overweight	25-30 kg/m2
	Obese	>30 kg/m2
	Daily fruit intake	Pieces of fruit
	Not-adequate	< 2 pieces
	Adequate	≥ 2 pieces
	Tobacco use	≥1 cigarette per day (yes/no)
	Alcohol use	≥1 glass of alcohol per week (yes/no)
	Folic acid use	Use of folic acid, either as a single supplement or as part of multivitamin preparation (yes/no)
	Vitamin use	Use of vitamin C, vitamin D or calcium supplement either as a single supplement or as part of multivitamin preparation (yes/no)
Socio-demographic characteristics (Self-reported in the first trimester)	Age	Years
	Ethnicity	- White: Caucasian or other Western;
		- Non-White: African, Hindustani, Moroccan, Turkish, Middle Eastern, Asian, other non-western, and mixed.
	Educational level	- Low: primary education or lower level;
		- Medium: secondary education;
		- High: tertiary education or higher level.
	Parity	- Nulliparous: women with no previous pregnancies beyond 16 weeks;
		- Multiparous: women with previous pregnancies beyond 16 weeks.
	Mode of conception	- Spontaneous conception: pregnant without medical assistance;
		- Non-spontaneous conception: pregnant with ovulation drugs, insemination or in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI).
Adverse pregnancy outcomes (Reported by the healthcare provider after the pregnancy)	Hypertensive disorder in pregnancy (HDP)	Either:
		- Pregnancy-induced hypertension (PIH): the new onset of hypertension (≥ 140 mmHg systolic and/or ≥90 mmHg diastolic blood pressure) after 20 weeks gestation measured on at least two occasions four hours apart;
		- Pre-eclampsia (PE): PIH accompanied by proteinuria (≥300 mg in 24 hours), either during pregnancy or postpartum [24, 25, 26].
	Small for gestation age (SGA)	A birth weight <3rd percentile, based on Hoftiezer percentiles [27, 28].
	Gestational diabetes (GDM)	The presence of either a fasting glucose level of ≥7.0 mmol/L (126 mg/dl) or a glucose level of ≥7.8 mmol/L (140 mg/dl) two hours after a 75-grams oral glucose tolerance test [29–31].
	Spontaneous preterm birth (sPTB)	A delivery with spontaneous onset before 37 weeks of gestation [32].
	Composite outcome	Women with one of the following complications; pregnancy-induced hypertension, pre-eclampsia, small for gestational age <p3, gestational diabetes, spontaneous preterm birth or fetal death.