Table 1: Characteristics of the study population (n=3,437).

Data are given as median [interquartile range] or number (%). Maternal height and weight were recorded in inches and pounds and then converted into cm and kg, respectively, prior to analysis.

Characteristic	Statistic
Maternal age (y)	23 [20–27]
Parity
Nulliparous	1259 (36.6%)
Multiparous	2178 (63.4%)
Body mass index	27.5 [22.9–33.7]
Height (cm)	162.6(157.5–167.6)
Weight (kg)	72.6(60.8–90.3)
Smoking status
Smoker	634 (18.5%)
Non-smoker	2803 (81.5%)
Gestational age at delivery (weeks)	39.0 [38.0–39.9]
Interval from scan to delivery (weeks)	2.6 [1.0–5.3]
Preterm delivery	478 (13.9 %)
Mode of delivery
Vaginal	2475 (72.0%)
Caesarean section	962 (28.0%)
Sex
Male	1755 (51.1%)
Female	1682 (48.9%)
Birthweight (g)	3145 [2790–3465]
SGA by Alexander	341 (9.9%)