Objective: This paper reports on the status of lactose digestion during early and late pregnancy and at 8 weeks postpartum in an African-American population. The hypothesis is that lactose digestion and milk tolerance do not change throughout pregnancy and do not differ from those of non-pregnant African-American women.
Design and subjects: This longitudinal study determined lactose digestion after ingesting 240 ml of 1% fat milk containing 12 g of lactose at: (1) early pregnancy, prior to 16 weeks (n=148); (2) late pregnancy, 30-35 weeks (n=77); and (3) 8 weeks postpartum (n=93). One hundred and one comparably matched non-pregnant African-American women served as controls.
Results: Prevalence of lactose digestion, as measured by breath hydrogen, was 80.2% in the control women, 66.2% in early pregnancy, 68.8% in late pregnancy and 75.3% postpartum. The prevalence of women reporting symptoms was approximately 20% regardless of lactose absorption status. However, the control women reported significantly more symptoms than did the pregnant women.
Conclusions: This study indicates that there is no significant change in lactose digestion during pregnancy. The prevalence of lactose intolerance for the pregnant African-American women studied is similar to that for non-pregnant African-American women and similar to previous prevalence reports in adult African-Americans. There was no change in the tolerance of lactose noted during pregnancy in these women. There were, however, fewer symptoms reported by the lactose-maldigesting pregnant women.