New study suggests full-fat milk may support fetal growth in pregnancy

Research published in Nature indicates that consuming more milk, especially full-fat varieties, during pregnancy could reduce the risk of small for gestational age births, highlighting the potential biological benefits of dairy intake for fetal growth.

Milk intake during pregnancy may lower the risk of small for gestational age births, according to a study published in Nature and supported by earlier cohort and review evidence. The new research found that women who consumed more milk were less likely to give birth to babies who were small for their gestational age, while higher milk protein intake was also linked with a lower risk. The study did not find a clear connection with large for gestational age births, suggesting the effect may be more about preventing restricted growth than pushing birth size too far in the other direction.

The findings add to a broader body of work suggesting that milk and dairy products can support fetal growth. A large Danish cohort published in 2007 reported that women who drank more milk during pregnancy had fewer small for gestational age babies and heavier infants overall. A later systematic review and meta-analysis also found that higher intake of milk and related products was tied to greater birth weight and a lower risk of small for gestational age and low birth weight. Another review reached a similar conclusion, saying maternal milk or dairy intake was positively associated with birth weight.

The Nature study is notable because it comes from a population with relatively low average milk intake. The researchers reported that the average daily intake was far below levels seen in some European cohorts, where dose-response links were easier to detect. That may help explain why some earlier studies found stronger or more consistent trends than others. The authors also suggested that the type of milk consumed could matter, noting that when full-fat milk drinkers were excluded, the associations largely disappeared. They concluded that full-fat milk may be particularly relevant to fetal growth in that setting.

The study also pointed to possible biological mechanisms. Milk can raise insulin-like growth factor-1, a hormone linked with growth, and it supplies protein, calcium and other nutrients that may support the developing fetus. Still, the authors cautioned that more research is needed to decide whether low-fat or full-fat milk is the better choice in pregnancy. They also noted the limits of dietary questionnaires and the possibility of unmeasured confounding, even in a large, carefully adjusted analysis.