Table 3. Hazard ratios for the association between body size and SAB when adjusting for potential confounders measured at baseline.

Exposure	N SABa	Total GWsa	Unadjusted HR	Adjusted model HR [95% CI]b	Adjusted model with body size HR [95% CI]c
Body mass index (kg/m2)
<20	108	14 992	0.99	1.00 [0.81, 1.24]	0.93 [0.73, 1.19]
20–24	385	52 959		1.00 [Reference]
25–29	135	20 694	0.90	0.90 [0.73, 1.09]	0.94 [0.71, 1.23]
≥30	104	11 634	1.22	1.23 [0.98, 1.54]	1.26 [0.87, 1.83]
Waist circumference
<75 cm	199	25 500		1.00 [Reference]
75–79 cm	165	23 120	0.94	0.92 [0.73, 1.16]	0.91 [0.71, 1.17]
80–86 cm	150	23 115	0.85	0.82 [0.65, 1.03]	0.80 [0.61, 1.06]
≥87 cm	218	28 544	1.00	0.97 [0.75, 1.25]	0.88 [0.57, 1.36]
Waist-to-hip ratio
<0.75	186	21 024		1.00 [Reference]
0.75–0.79	175	24 316	0.86	0.85 [0.67, 1.06]	0.84 [0.67, 1.06]
0.80–0.84	166	24 695	0.79	0.76 [0.58, 1.00]	0.75 [0.57, 0.99]
≥0.85	205	30 244	0.85	0.81 [0.63, 1.05]	0.78 [0.59, 1.03]
Height
<166 cm	233	31 550		1.00 [Reference]
166–169 cm	180	21 151	1.15	1.14 [0.93, 1.38]	1.12 [0.92, 1.37]
170–173 cm	171	23 058	1.00	0.99 [0.81, 1.21]	0.97 [0.79, 1.18]
≥174 cm	148	24 520	0.82	0.81 [0.66, 1.00]	0.79 [0.63, 0.98]
Location of weight gain
Equally all over	198	27 464		1.00 [Reference]
Waist/stomach	300	40 975	1.01	1.01 [0.84, 1.21]	1.02 [0.85, 1.23]
Hips/thighs	198	26 754	1.03	1.03 [0.84, 1.26]	1.04 [0.85, 1.27]
Does not gain weight	27	4204	0.88	0.88 [0.59, 1.32]	0.89 [0.59, 1.35]
Chest/ shoulders	9	882	1.18	1.15 [0.50, 2.65]	1.15 [0.50, 2.65]

^aFrequencies and gestational weeks (GW) from the first imputation dataset.

^bAdjusted for maternal age, physical activity, caffeine consumption, parity, vocational training/education, alcohol consumption, and smoking.

^cAdjusted for variables in footnote b and body size (BMI model adjusted for waist circumference, height model adjusted for weight; all other models adjusted for BMI.