Periconceptional multivitamin use and risk of preterm or small-for-gestational-age births

This study examined the relationship between periconceptional multivitamin use and the risk of small-for-gestational-age (SGA: <>th to <> preterm ( <>

Data were collected from Women in the Pregnancy Exposures and Preeclampsia Prevention Study (1997–2001) who had reported their regular multivitamin use in the past 6 months (n = 1823) at enrolment. The following findings were reported:

• 47% of women regularly used periconceptional multivitamins
• Periconceptional multivitamin use was associated with a reduced risk of preterm births (<> (OR) = 0.29, 95% CI: 0.13 to 0.64) and spontaneous preterm births (<>

• There was a trend towards a lower risk of SGA (<> 0.64: 0.40 to 1.03).
• There was no effect of multivitamin use on risk of preterm births (34 to <> weeks) or SGA (5^th to <>
• Sensitivity analysis for unmeasured confounding by folate intake supported these findings.

The authors of the study suggest from these preliminary findings that “periconceptional vitamin use is associated with lower rates of severe preterm births and extreme SGA.” However they stress that these data should be considered cautiously until they have been replicated as there were several important limitations of their data such as the self-reported nature of vitamin use, and unmeasured factors relating to lifestyle, nutrition, access to health care, and maternal genetic variation.

Am J Epidemiol 2007;166:296-303 - Abstract