Pre-term birth (PTB) and small-for-gestational-age (SGA) births are leading risk factors of morbidity and mortality in newborns. Previous observations have indicated that multivitamins taken periconceptually (just before and just after a woman becomes pregnant) may decrease the risk of PTB and SGA.
The objective of a new study was to relate the timing and frequency of periconceptional multivitamin use to risk of a PTB or delivery of SGA infants.
Participants included 35,897 women in the Danish National Birth Cohort. The women were asked to report the number of weeks of multivitamin use during a 12-week periconceptional period. Researchers analyzed the relation between any multivitamin use and PTBs (less than 37 weeks) or SGA births. The timing (preconception and postconception) and frequency of use were also analyzed. Regular users (4–6 weeks) and partial users (1–3 weeks) in each period were compared with nonusers.
The association between periconceptional multivitamin use and PTBs varied according to prepregnancy overweight status. Regular preconception and postconception multivitamin use in women with a prepregnancy BMI <25 (normal weight) was associated with reduced risks of a PTB and preterm labor. The association between multivitamin use and PTB was not evident in women who were overweight. The risk of an SGA birth was decreased in multivitamin users regardless of their prepregnancy weight, with the strongest association in the postconception period.
In this study, regular multivitamin use around the time of conception was associated with reductions in risk of PTBs in nonoverweight women and of SGA regardless of their prepregnancy weight. This research supports the assertion that multivitamin use around the time of conception could be a safe and simple strategy to improve pregnancy outcomes.
Janet M Catov et al. Periconceptional multivitamin use and risk of preterm or small-for-gestational-age births in the Danish National Birth Cohort. First published July 27, 2011, doi: 10.3945/ajcn.111.012393 Am J Clin Nutr September 2011 ajcn.012393
