Wehby, G. L. (2014). Breastfeeding and child disability: A comparison of siblings from the United States. Economics and Human Biology, 15, 13-22.
Research Review: Alex X. Martínez
An extensive body of evidence suggests that breastfeeding is associated with improvements in health outcomes, infant’s physical growth, achievement of developmental milestones, cognitive ability, and long-term educational achievement. However, it remains unclear whether breastfeeding may reduce the risk of disability in the form of physical and cognitive limitations. Closing this gap in the literature is relevant considering that during the past few decades the prevalence of children with a disability in the United States has increased while the rate of breastfeeding has fluctuated. The positive effects of breastfeeding on children and developmental outcomes and the contrasting trends between child disability and breastfeeding over several periods in the past four decades may suggest a potential effect of breastfeeding on child disability. Nonetheless, it is still unclear whether the declines in breastfeeding over the past four decades may have contributed to the increase in disability rates and whether the recent increase in breastfeeding rates may reduce future disability rates.
The purpose of this study was to evaluate the effects of breastfeeding on child disability using a nationally representative sample. The data was collected from the 1995 National Survey of Family Growth (NSFG) merged with the 1993 National Health Interview Survey (NHIS) including children from one to 18 years old. The NSFG provides the data on breastfeeding and several other maternal and child characteristics such as maternal age at pregnancy and the child’s sex and birth outcomes, while the NHIS provides the data on child disability. The effect of breastfeeding on disability was determined by comparing disability status between siblings who differed in breastfeeding duration.
About 6.7% of the sample children were reported as having a disability. The average breastfeeding time was 3.5 months when assigning 0s for children who were not breastfed at all and 6.7 months among breastfed children. The probability models used to determine breastfeeding duration effects on disabilities suggest a similar negative effect on child disability whether all children are included or only siblings discordant in breastfeeding are included. Breastfeeding the child for an additional month is associated with a lower probability of disability by about 0.2 percentage-points, or by about 3% relative to the population disability rate. Breastfeeding for six months compared to no breastfeeding is associated with a lower risk of disability by 1.3 percentage-points or 19% relative to the population disability rate of 6.7% while very short breastfeeding durations are unlikely to have an effect on reducing disability risk. Future research should focus on studying the effects of breastfeeding duration on the severity of the disability and whether child-specific factors such as weight and gestational age influence the choice and duration of breastfeeding.