Table 9.

Summary of the outcome of studies on birth weight in which exposure was used as continuous variable

Reference	Study design	Exposure	Timing of exposure/assessment	Compound	Unit	Exposure ‐ study median (IQR)	n Total	Unit	Mean difference (95% CI)	Adjusted
Chen et al. (2015)	PC	Plasma	Drawn at 26–28 gw	Vitamin B6 (generic)	nmol/L	61.8 (25.9–113)	968	g per one SD higher log vitamin B6 plasma concentration	−3.9 (−30.7, 22.9)	Yes
Lagiou et al. (2005)	PC	Intake	During first 27 gw	Dietary intake	mg/day	4.1 (2.6–5.9)	222	g per one SD higher vitamin B6 intake	2.7 (−54.4, 59.7)	Yes

CI: confidence interval; gw: gestational weeks; IQR: interquartile range; PC: prospective cohort study; SD: standard deviation.