In malnourished regions in Bangladesh, the earlier in pregnancy women receive micronutrient and food supplements, the greater will be the benefit in terms of infant and child mortality, a report in JAMA shows.
Children born to women who received supplements starting at around nine weeks gestation were 62% less likely to die in infancy and 66% less likely to die before five years of age than children of women who began using food supplements when they were around 20 weeks pregnant.
Dr Lars Ake Persson of University Hospital in Uppsala, Sweden, who led the study, told Reuters Health that prenatal food supplementation has focused on the third trimester, given the rapid foetal growth in this period. "On the other hand, the period when the placenta is developing and the whole system for supplying nutrition to the small foetus is developing is during the first trimester," he added.
He and his colleagues believed that starting food supplementation early, along with multiple micronutrient supplementation, would increase maternal haemoglobin and birth weight and reduce infant mortality.
No differences in mean birth weight
To investigate, they randomly assigned 4 436 pregnant women living in rural Bangladesh to be invited to begin food supplementation at roughly nine weeks gestation, or at the time of their choice.
Women in each group were also randomly assigned to supplementation with 30 mg iron and 400 mcg folic acid; 60 mg iron and 400 mcg folic acid; or multiple micronutrient supplementations (MMS) with iron, folate, and 13 other recommended micronutrients.
There were 3 625 live births, and data was available for analysis on 3 267 singleton newborns. No differences were seen among the groups in maternal haemoglobin levels at 30 weeks, nor were there any differences in mean birth weight.
However, infant mortality per 1 000 live births was 16.8 in the early nutrition/MMS group, vs. 44.1 in the usual invitation group taking 60 mg iron and 400 mcg folic acid.
And among children under age five, mortality per 1 000 live births was 18 in the early invitation/MMS group and 54 when mothers started food supplements later and were assigned to the 60/400 iron and folic acid regimen.
Spontaneous abortions high on MMS group
Infant mortality and the incidence of spontaneous abortions were the highest among the women given MMS who began receiving food supplementation later in pregnancy. Most infant deaths were due to asphyxia.
"It may be so that if you give multiple micronutrients without securing a good supply of energy and protein at an early stage in pregnancy, it may be risky," Dr Persson said. "It has been advocated by others that you should have blanket supplementation of micronutrients to pregnant women. We believe that should be discussed much more before it is done."
In an editorial, Dr Parul Christian and Dr Robert E. Black of The Johns Hopkins Bloomberg School of Public Health in Baltimore write, "The timing and components of food and multiple micronutrients during pregnancy remain complex and controversial."
Other studies, Dr Black noted in an interview, have found risks associated with early micronutrient supplementation. One possible explanation, he added, is that multiple micronutrient supplementations could have increased the size of foetuses that were already on the larger end of the spectrum, making obstructed delivery more likely.
(Anne Harding, Reuters Health, May 2012)
Child mortality rate increasing