Folic acid late in pregnancy may increase childhood allergy risk

December 22, 2017

Research from the University of Adelaide suggests that taking folic acid in late pregnancy may increase the risk of allergies in children affected by growth restriction during pregnancy.

Folic acid, a type of B vitamin, is widely used to prevent neural tube defects in the fetus, and to aid in the development of the central nervous system. The neural tube develops in the first month of pregnancy, and Australian guidelines recommend that women take a daily folic acid supplement at least one month before, and three months after conception.

"Taking a folic acid supplement during the first trimester of pregnancy is important to reduce the risk of neural tube defects," says Dr Kathy Gatford from the University of Adelaide's Robinson Research Institute.

"However, continued supplementation with folic acid into the later stage of pregnancy doesn't reduce that risk, and there's growing evidence that this may increase the risk of allergies in offspring," Dr Gatford says.

Allergies are one of the main causes of non-communicable diseases in the world and are estimated to affect 30-40% of the world's population. Susceptibility to these diseases after birth is partly determined by an individual's early life environment.

Previous research has also shown that a complication of pregnancy known as intrauterine growth restriction (IUGR) - a form of growth restriction in the womb often resulting in lower birth weight - may in fact have a protective effect against childhood allergies.

In studies of sheep born from normal or growth-restricted pregnancies, Dr Gatford and colleagues measured skin reactions to two common allergens: dust mites and egg whites.

"Sheep from growth-restricted pregnancies were less likely to have allergic reactions to egg white protein than those born to normal pregnancies. Importantly, if the sheep with growth restricted pregnancies were fed supplements containing folic acid in late pregnancy, their offspring had similar rates of allergic reactions as control progeny," Dr Gatford says.

"Our findings suggest that folic acid supplementation partially reduced the protection that has previously been seen in pregnancies with restricted growth.

"Studies in animal models like this allow us to directly investigate these effects of the environment before birth on later allergy. While the results help us to better understand the potential allergy risk in humans, more research is needed before any recommendations about the right timing of supplementation should or could be made in humans," she says.

"We are now in the process of analyzing how a growth-restricted pregnancy and the dietary supplement affect the nutrient status of offspring at birth, and how this might switch on or off genes that regulate the immune system."
-end-
This research has been funded by the National Health and Medical Research Council (NHMRC). It is published online ahead of print in the American Journal of Physiology--Regulatory, Integrative and Comparative Physiology.

University of Adelaide

Related Pregnancy Articles from Brightsurf:

COVID-19 has a prolonged effect for many during pregnancy
Symptoms for pregnant women with COVID-19 can be prolonged, lasting two months or longer for a quarter of the women who participated in a national study led by UC San Francisco and UCLA.

Relaxed through pregnancy
A group of researchers from Charité - Universitätsmedizin Berlin have been able to show that maternal psychological wellbeing during pregnancy has a positive effect on newborn infants.

Trajectories of antidepressant medication use during pregnancy
In an analysis of women who started pregnancy when taking antidepressant medications, investigators identified three trajectories of antidepressant dispensing during pregnancy: more than half stopped their treatment, a quarter maintained their treatment throughout pregnancy, and one-fifth discontinued it for a minimum of three months and then resumed it during the postpartum period.

Are women using e-cigarettes during preconception and/or pregnancy?
A new study of 1,365 racially/ethnically diverse, low-income pregnant women found that 4% reported e-cigarette use.

A better pregnancy test for whales
To determine whale pregnancy, researchers have relied on visual cues or hormone tests of blubber collected via darts, but the results were often inconclusive.

Cannabis use during pregnancy
The large health care system Kaiser Permanente Northern California provides universal screening for prenatal cannabis use in women during pregnancy by self-report and urine toxicology testing.

Questions and answers about cannabis use during pregnancy
A new study shows that women have many medical questions about the use of cannabis both before and during pregnancy, and during the postpartum period while breastfeeding.

The effect of taking antidepressants during pregnancy
Exposure to antidepressants during pregnancy and the first weeks of life can alter sensory processing well into adulthood, according to research in mice recently published in eNeuro.

Is ivermectin safe during pregnancy?
Is it safe to give ivermectin to pregnant women? To answer this question, researchers from the Barcelona Institute for Global Health (ISGlobal), an institution supported by 'la Caixa,' conducted a systematic review and meta-analysis of studies that reported cases of accidental exposure to the drug among pregnant women.

Going to sleep on your back in late pregnancy
This study looked at whether going to sleep on your back in the third trimester of pregnancy was associated with average lower birth weights.

Read More: Pregnancy News and Pregnancy Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.