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RCOG statement: New BJOG study suggests folic acid supplementation pre-conception can reduce SGA risk

News 26 November 2014

A new study published today (26 November) in BJOG: An International Journal of Obstetrics and Gynaecology suggests pre-conceptual folic acid supplementation significantly reduces the risk of small for gestational age (SGA) at birth.

The UK study examined the effect of timing of folic acid supplementation during pregnancy on the risk of the baby being SGA at birth, defined as birth weight less than the 10th centile or in the lowest 10% of babies born.

Results show that the overall proportion of babies with a birth weight under the 10th and 5th centile was 13.4% and 7% respectively. The highest rate of SGA occurred in pregnancies where no folate had been taken, with 16.3% under the 10th centile and 8.9% under the 5th centile.

When comparing pre- and post-conceptual folic acid supplementation, the prevalence of birth weight lower than the 10th centile was 9.9% and 13.8% respectively, while that of birth weight under the 5th centile was 4.8% and 7.1% respectively.

The authors of the study conclude that the number of women who take folic acid pre-conceptually is low and new strategies must be developed to increase uptake.

Commenting on the study, Vice President of Clinical Quality for the Royal College of Obstetricians and Gynaecologists (RCOG), Professor Alan Cameron said:

“It is currently a standard recommendation in the NICE antenatal care guidelines for women to take folic acid supplements before conception and for the first 12 weeks of pregnancy and the RCOG supports this, recommending folic acid to women.

“There is a good scientific evidence base to suggest folic acid reduces the number of pregnancies affected by neural tube defects (NTD), such as spina bifida. This study provides further evidence of the positive health benefits of folic acid with regards to reducing the number of SGA babies born in the UK.

“A small baby can mean no complications if the baby is healthy. However, in some cases, if the baby is growth restricted, there is an increased risk of complications and poor outcomes.”

“Previous research has suggested that only around one-third of women take folic acid supplements pre-conceptually. Therefore, strategies to increase uptake must be evaluated as some women may not plan their pregnancy.

“The RCOG supports a food fortification policy with mandatory fortification of bread or flour with folic acid as a public health measure to improve the lives of both mothers and babies. This will reach women most at risk due to poor dietary habits or socioeconomic status.”


For further information, please contact the RCOG Media and PR team on +44 20 7772 6300 or email


The RCOG Scientific Impact Paper Periconceptional Folic Acid and Food Fortification in the Prevention of Neural Tube Defects is available to view here.

The RCOG Patient Information Healthy eating and vitamin supplements in pregnancy is available here.


Hodgetts VA, Morris RK, Francis A, Gardosi J, Ismail KM. 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. BJOG 2014;