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Paternal Preconception Folate Intake Affects Duration of Pregnancy

Key findings

  • This prospective cohort study of 108 subfertile couples undergoing fertility treatment evaluated the relationship between parental preconception diet and perinatal outcomes
  • Paternal folate intake prior to conception was associated with a longer duration of pregnancy (2.6 days for every 400-mcg/day increase in intake), after accounting for potential confounders including maternal folate intake
  • Maternal preconception folate intake was unrelated to duration of pregnancy
  • If confirmed, these findings suggest that preconception care should shift from being woman-centric to being couples-based

There's growing interest in how pregnancy outcomes might be affected by parental health and lifestyle before conception. In previous research published in The American Journal of Clinical Nutrition, Jorge Chavarro, MD, ScD, associate professor in the Departments of Nutrition and Epidemiology at the Harvard T.H. Chan School of Public Health, and colleagues at the Massachusetts General Hospital Fertility Center determined that maternal preconception dietary and serum folate were related to a higher probability of live birth among couples undergoing infertility treatment.

Now, Dr. Chavarro, along with Russ Hauser, MD, MPH, ScD, chair of the Department of Environmental Health at the Harvard T.H. Chan School of Public Health, and fertility specialist Irene Souter, MD, and colleagues have extended the evidence in this area. In Reproductive BioMedicine Online, they report that paternal folate intake before conception is associated with the duration of gestation in pregnancies achieved by assisted reproduction. Assuming the findings can be confirmed in other populations, they suggest that a father's diet before conceiving a child has an impact on that child's health.

Study Details

The Environment and Reproductive Health (EARTH) study, an ongoing prospective cohort study started in 2004, aims to identify environmental and dietary factors associated with human fertility. The researchers collected comprehensive data about maternal and paternal preconception diets from 108 subfertile couples (who has 113 pregnancies) at the Mass General Fertility Center between 2007 and 2017. These couples had 142 live births (85 singletons, 54 twins and three triplets).

Folate Intake

Micronutrient intakes were estimated by adding the contributions from food and supplements. The average preconception folate intake (dietary folate equivalents) was 989 mcg/day among fathers and 1,797 mcg/day among mothers. 56% of fathers and 98% of mothers were taking folic acid supplements.

Moderate correlation was found between maternal and paternal folate intake (r = 0.21; P = .002). This suggests a need to account for paternal folate intake in studies of how maternal folate intake affects pregnancy outcomes.

Perinatal Outcomes

Paternal preconception folate intake was associated with a longer duration of gestation. Specifically, a 400-mcg/day increase in paternal folate intake was associated with a 2.6-day (95% CI, 0.8–4.3) longer gestation after accounting for potential confounders, including maternal folate intake. The association was similar whether folate came from food or supplements.

They also found that maternal preconception folate intake was unrelated to the duration of gestation. Also, neither paternal nor maternal preconception folate intake was significantly related to the risk of prematurity, gestational age–specific birth weight or risk of the offspring being small for gestational age.

Research Implications

Studying couples who were undergoing infertility treatment allowed the researchers to obtain data that is quite rare in pregnancy cohorts:

  • Precise timing of diet in relation to pregnancy initiation
  • Detailed information from the father

However, this design may impact generalizability, and the study findings will need to be confirmed in couples not undergoing medically-assisted reproduction.

Once confirmed, the findings would have great importance. If it can be demonstrated that paternal preconception diet and other lifestyle choices affect the health of the offspring, preconception care should be not woman-centric but instead couple-based.

day longer gestation with a 400-mcg/day increase in paternal folate intake

Learn more about the Mass General Fertility Center

Learn more about fertility research at Mass General

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