A new study has investigated the impact of folic acid on birth weight and gestational age. Folic acid a vitamin B derivative has been recommended for women during pregnancies for many years as it reduces the risk of the child developing spina bifida.
Babies that are small for gestational age (SGA) are attributed to fetal problems during pregnancy caused by intrauterine growth restriction. The fetus fails to receive the required nutrients and oxygen it needs to grow.
SGA can cause a diversity of problems at birth including reduced oxygen levels, polycythemia (excess red blood cells) and low blood sugar. It can also increase the risk of adverse health problems later in life such as diabetes, high blood pressure, obesity, cardiovascular disease and mental health issues.
The researchers identified 108,525 pregnancies whereby data on mothers’ folic acid supplementation was accessible. Almost 85% of women had taken folic acid during pregnancy. Information on when women began taking folic acid was available for 39,416 women. Of these, 10,036 (25.5%) began taking folic acid prior to conception.
Overall, 19.3% of babies were born SGA; 13.4% of these babies had a birth weight in the lowest 10%, while 7% of babies had a birth weight in the lowest 5%.
Results of the study revealed that the highest rates of SGA occurred among babies whose mothers had not taken folic acid before conception or during pregnancy, with 16.3% of these babies born with a weight in the lowest 10% and 8.9% born with a weight in the lowest 5%.
Of the mothers who began taking folic acid during pregnancy, 13.4% had babies with a birth weight in the lowest 10%, while 7.1% had babies with a birth weight in the lowest 5%.
Among women who began taking folic acid prior to conception, however, the percentage of babies with a birth weight in the lowest 10% stood at 9.9%, while the percentage with a birth weight in the lowest 5% was 4.8%. This indicates that taking folic acid before conception can significantly reduce the risk of SGA.
“Increased uptake of folic acid prior to pregnancy and throughout the first trimester could have significant public health benefits given the poor outcomes associated with SGA babies. New strategies are therefore vital to improve the lives of both mothers and babies,” said Khaled Ismail of the University of Birmingham in the UK.
Effectiveness of folic acid supplementation in pregnancy on reducing the risk of small-for-gestational age neonates: a population study, systematic review and meta-analysis, Khaled Ismail, et al., BJOG: An International Journal of Obstetrics & Gynaecology, doi: 10.1111/1471-0528.13202, published online 26 November 2014, abstract.