Lactose Intolerance in Pregnant African-American Women

Abstract

LEARNING OUTCOME: To state the prevalence and effects of lactose intolerance in pregnant African-American women Objective: To determine the prevalence of lactose intolerance in pregnant African-American women, any change in tolerance that may occur and reported symptoms after consuming 240 ml of 1% milk. Design: This longitudinal study compared lactose status: 1) prior to 16 weeks gestation, 2) between the 30th and 35th week and 3) at 8 weeks post-partum. Similar non-pregnant control women were independently studied at one point. Subjects: 148 pregnant and 101 non-pregnant African-American women were randomly selected from 4 clinics. Subjects were free of metabolic disease, intestinal disease, eligible for the WIC program and free of obstetric complications. Control women met all study criteria. Main outcome measures: Breath hydrogen was collected hourly for 8 hours following ingestion of 240 ml of 1% milk. A breath hydrogen rise of > 20 ppm indicated lactose intolerance. Symptoms of flatulence, diarrhea, abdominal pain and bloating were continuously monitored and reported during the 8 hours. Statistical analysis: Results were analyzed using two-tailed t tests and x 2 test. Results: Prevalence of lactose intolerance was 80.2% in the control women, 66.4% in early pregnancy, 68.8% during late pregnancy and 75.3% at post-partum. There was no statistically significant change in lactose digestion during pregnancy. Control women reported significantly more symptoms than the pregnant women. An increase in intestinal transit time was evidenced by breath hydrogen peak at 5 hours during early and late pregnancy and at 4 hours post-partum and for controls. Conclusions: Prevalence of lactose intolerance in pregnant African-American women is similar to non-pregnant African-American women. There appears to be no physiologic adaptation to lactose during pregnancy; as previously reported in the literature. Symptoms caused by milk may be lessened during pregnancy due to increased intestinal transit time. Pregnant African-American women need nutrition counseling which considers this information and informs their decision regarding milk or alternative sources of protein and calcium.