Table 3.

Multivariate linear regression models examining the effect of body mass index (BMI) on A. TSH and B. Free T4 when adjusted by maternal age, TPO antibodies, parity, sex of the newborn, weeks of gestation, and smoking.

A.
TSH* (n=557)	Regression coefficient	Standard Error	p-value
BMI	0.009057	0.0043117	0.036
Age	−0.0039257	0.0038971	0.314
TPO Antibodies	0.3768184	0.0699704	0.000
Parity 1	−0.0935275	0.0520008	0.073
Parity ≥ 2	0.0026789	0.0650321	0.967
Sex of newborn	0.0911571	0.0413148	0.028
Gestation (weeks)	0.0040729	0.0086249	0.637
Smoking	−0.0974039	0.0639362	0.128
Intercept	1.394582	0.1936655	0.000

B.
Free T4 (n=560)	Regression coefficient	Standard Error	p-value
BMI	− 0.0899735	0.0167457	0.000
Age	− 0.0396639	0.0150878	0.009
TPO Antibodies	− 0.7663849	0.2622203	0.004
Parity 1	0.1713447	0.2008147	0.394
Parity 2	− 0.284663	0.251601	0.258
Sex of newborn	0.098168	0.1597093	0.539
Gestation (weeks)	− 0.1946608	0.0332834	0.000
Smoking	0.2690603	0.247179	0.277
Intercept	19.18689	0.7483954	0.000

^*TSH is square-root transformed

¥ R² = 7.97%

¥ R² = 16.3%