There seems to be a run of research being released at the moment looking at pregnancy and fertility related issues, as you can see from my recent blog posts.  In a recent review paper (1) researchers have estimated that 1.5million fewer babies would be born at low birth weights every year if all pregnant women, worldwide, took vitamin and mineral supplements. 

The lead researcher of the study, Dr Prakesh Shah, stated in a press release (2) that women should start taking vitamin and mineral supplements “as soon as they know they are pregnant”.  Compared with women who took a placebo, women who took multi-nutrient supplements were 19% less likely to have a low birth weight baby.

Low birth weight infants, those born weighing less than 2.5 kilograms (about 5.5 pounds), face a greater risk of health problems that may extend into adulthood. They tend to be more vulnerable to infections during infancy and childhood and may be more likely to have developmental problems in childhood.  As adults they may be at greater risk of diabetes and high blood pressure.  This study (1) found that “Prenatal multimicronutrient supplementation was associated with a significantly reduced risk of low birth weight and with improved birth weight when compared with iron–folic acid supplementation”.

Currently, the World Health Organization (WHO) recommends supplementation with folic acid and iron during pregnancy.  However there have been numerous studies showing that a number of different vitamins/minerals may be necessary in early pregnancy for the best outcomes for mother and baby.  In this current study (1) when compared with women taking iron and folic acid only, the researchers found the multi-supplement users had a 17% risk of having a low birth weight baby.  Babies born to women taking multimicronutrient supplements weighed 54 grams more, on average, than babies born to women taking iron and folic acid alone.  The authors of the study suggest that the WHO could consider revisiting their guidelines to recommend multi-nutrient supplements, not just iron and folic acid, for all pregnant women.

The research is limited by the fact that it is a review study of already published data, not an intervention trial.  In addition to this the studies included in the review varied with regards timing, duration, composition of micronutrients, and characteristics of the study populations.  In populations where under-nutrition is common the multi-nutrient supplement may be more helpful than in populations where nutrient rich diets are eaten.  However there is a growing increase in teenage pregnancy here in the UK and often these children are not following a healthy diet and may well be lacking in a number of vitamins and minerals.  In addition to this my previous posts have shown that many nutrients in early and pre pregnancy are associated with better health in mothers and children in Western populations, so it does seem that multi-nutrient supplements could be important for all pregnant women.

Supplements designed especially for pregnant women are widely available, however it is always a good idea to check with your doctor or midwife before taking any supplements during pregnancy.  As mentioned last week – a healthy balanced diet also very important at all times, but especially during pregnancy.

(1)Prakesh S. Shah et al.  2009.   Effects of prenatal multimicronutrient supplementation on pregnancy outcomes: a meta-analysis.  CMAJ.  June 9, 180 (12). doi:10.1503/cmaj.081777.
(2)Anne Harding.  Multivitamins best for preventing low birth weight.  08/06/2009.  Reuters Health.  http://www.reutershealth.com/archive/2009/06/08/eline/links/20090608elin005.html
(3) Canadian Medical Association Journal (2009, June 8). Multivitamins In Pregnancy Reduce Risk Of Low Birth Weights. ScienceDaily. Retrieved June 9, 2009, from http://www.sciencedaily.com/releases/2009/06/090608182549.htm

(4)Bhutta ZA & Haider BA.  2009.  Prenatal micronutrient supplementation: Are we there yet?  Commentary.  CMAJ • June 9, 2009; 180 (12). doi:10.1503/cmaj.090652

Written by Ani Kowal