Differences in infant feeding practices by mode of conception in a United States cohort

Capsule:
Women who conceived with fertility treatments were more likely to stop breast feeding and provide formula to their infants earlier. A higher prevalence of preterm birth does not fully explain these associations.

Authors:
Kara A. Michels, Ph.D., M.P.H., Sunni L. Mumford, Ph.D., Rajeshwari Sundaram, Ph.D., Erin M. Bell, Ph.D., Scott C. Bello, M.D., Edwina H. Yeung, Ph.D.

Volume 105, Issue 4, Pages 1014-1022

Abstract:

Objective:
To identify associations between fertility treatment use (assisted reproductive technologies, ovulation induction, and artificial insemination) and subsequent infant feeding practices.

Design:
The Upstate KIDS population-based cohort enrolled mothers who delivered live births, sampling on fertility treatment and plurality.

Setting:
Not applicable.

Patient(s):
Data regarding singletons and one randomly selected infant between twins were used.

Intervention(s):
Not applicable.

Main Outcome Measure(s):
Mothers reported breast feeding and formula feeding practices at 4, 8, and 12 months postpartum. Modified Poisson regression was used to compare risks for feeding practices by mode of conception. Marginal structural models were used to estimate the controlled direct effects of fertility treatment on feeding, independently from preterm birth.

Result(s):
Among 4,591 mothers, 1,361 (30%) conceived with the use of fertility treatments. Mothers who used fertility treatments were less likely to breast feed to 12 months after birth and were more likely to provide formula, solids, and juice by 4 months than mothers who did not conceive with treatments. Fertility treatment remained associated with breast feeding cessation and formula feeding in mediation analyses, suggesting that preterm birth does not fully explain these associations.

Conclusion(s):

Women who conceived with the use of fertility treatments were less likely to breast feed later in infancy and were more likely to provide formula, solids, and juice earlier in infancy. Our analyses accounted for confounding and preterm birth, but other contributing factors may include difficulties feeding twins or workplace breast feeding accommodations.

  • msamplaski

    I suspect that women who conceive with fertility treatments are more likely to have jobs that require them to return to work sooner and thus indirectly push moms to give their infants formula at an earlier age. We know that women using fertility treatments are of a higher socioeconomic status than age matched cohorts, and likely have jobs where breaks for pumping and breast-feeding are simply not feasible. We also know that women using ART are of an older age than women having natural pregnancies, and thus it is likely that they are further embedded in their professional careers, making taking prolonged time off or breaks for breast-feeding more challenging. A questionnaire to the mothers asking about these employment related influences would be an interesting followup.

    • Edwina Yeung

      Edwina Yeung • 4 minutes ago

      Thank you for your interest in our work and your insightful thoughts! We tried to explore both the type of job a mother may have and when she returned to work by looking at daycare initiation (on which we did have information). We did not find that our results changed dramatically when we accounted for daycare. More detailed information about the breast feeding allowances at work was not available but may be something of interest to pursue in the future.

Translate »