Studies of Pregnant & Breastfeeding Women
Table 2.4 presents summary data from several epidemiologic surveys collecting food and supplement intake data from pregnant or lactating women. More details on the specific surveys are included in Table 2.5. The two most recent US nutrition monitoring surveys, the 1999-2000 National Health and Nutrition Examination Survey (NHANES) and the 1994-96 Continuing Survey of Food Intake of Individuals (CSFII), each included 24HR (24-Hour Recall) interviews to assess diet and supplement intake. Neither survey included a sizable number of pregnant or lactating women. Table 2.6 presents the diet-related questions in each of these surveys as well as those in the integrated What We Eat in America-NHANES survey, which is currently in the field. The rationale for instrument selection for the integrated survey as well as the history of past CSFII and NHANES surveys was recently reviewed (9). The integrated What We Eat in America-NHANES includes two 24HR interviews, one in-person and one by telephone, and a propensity questionnaire (100-item NCI DHQ without portion size information). Supplement use is queried in a separate questionnaire on frequency, dosage, and duration of use of specific products. Neither the current survey, nor past NHANES or CSFII surveys, query pregnant or lactating participants any differently from other non-pregnant or non-lactating participants. No additional information related to their diet or supplement use is collected. Lactation is defined as any breastfeeding reported by the participant.
In 2000, the Danish National Birth cohort enrolled 60,000 pregnant women and achieved a 77% response rate for a 300-item self-administered FFQ (Food Frequency Questionnaire) (36). This national survey will enroll 100,000 women and follow their offspring for 20 years. Women are interviewed by telephone twice during pregnancy (12 and 30 weeks) and when the infant is 6 and 18 months. The Avon Longitudinal Study of Pregnancy and Childhood (ALSPAC) also uses an FFQ to examine the average daily intake of more than 12,000 women at 32 weeks gestation (37). This geographically-based cohort study is investigating factors influencing the health and development of infants and children. The FFQ in this survey contains questions on 43 food group items as well as detailed questions on 8 basic foods.
The US National WIC evaluation assessed intake of almost 4,000 women with two 24HR interviews (38). A survey of more than 2,000 pregnant women in North Carolina used the HHHQ (39), while Project Viva in Eastern Massachusetts studied more than 2,000 women with the HFFQ (40) and was able to estimate the extent to which this population changed fish consumption habits after a federal advisory recommending limited intake during pregnancy.
In 1990, the Institute of Medicine report Nutrition During Lactation identified a need for data on dietary intakes by, and nutrition status among, lactating women and their relationship to lactation performance. As evident from the limited data on lactating populations in Table 2.6, this recommendation remains relevant.
Last Modified: 11 Apr 2014