Assessing whether genetic scores explain extra variation in birthweight, when added to clinical and anthropometric measures

Table 3 Results of multivariable linear regression models testing the association between birthweight (adjusted for sex and gestational age) and maternal clinical characteristics, with and without the maternal genetic score

Variable	Change in birthweight (g) per 1 SD change in independent variable	95% Confidence Interval	t value	p-value
Model 2: maternal clinical characteristics (n = 549 parent-offspring trios). R² = 0.217; Adj-R² = 0.210
Intercept	3691	3643, 3740	149.1	<2e-16
Maternal age	−38	−73, − 3	−2.1	0.04
Maternal weight	125	89, 161	6.8	2 e-11
Mother’s smoking status^a	−280	− 377, − 182	−5.6	3 e-08
Parity^a	− 187	− 255, − 118	−5.3	2e-07
Mother’s fasting glucose at 28 weeks’ gestation	87	51, 123	4.7	3e-06
Model 3: maternal clinical characteristics and maternal genetics (n = 549 parent-offspring trios). R² = 0.244; Adj-R² = 0.233
Intercept	3790	3655, 3925	55.3	<2e-16
Maternal age	−42	−77, −8	−2.4	0.03
Maternal weight	121	85, 156	6.7	1e-10
Mother’s smoking status	− 273	− 369, − 176	−5.6	8e-08
Parity	−194	− 262, − 126	− 5.6	3e-08
Mother’s fasting glucose at 28 weeks’ gestation	85	49, 120	4.1	9e-07
Maternal genetic score for offspring birthweight (adjusted for fetal effects)	68	36, 101	4.7	0.0002

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