The East Java Pregnancy Study (EJPS)

This longitudinal study was conducted in a rural community on the island of Madura, East Java. Full data collection started in September 1982. The emphasis of the study in the first phase (until December 1985) was on maternal nutrition in pregnancy in relation to fetal growth and breast milk intake. The second phase focused more on nutrition of the mother-child pair in the preschool years (January 1987-December 1989). Except for birth weight recording, there were no field activities in 1986.

Details of the study population and methodology of data collection have been described in earlier publications (Steenbergen et al., 1989; Kardjati et al., 1990; Kusin et al., 1992 a, b, 1993).

Procedures and methods

In summary, the framework of EJPS was a surveillance of all mothers with children, age 0-60 months, and newly married couples through 4-weekly home visits to detect a pregnancy and to monitor the growth of children. On these occasions the weight of the mothers was also measured, providing prepregnant, and post-partum weights, and birth weight was measured within 24 h of delivery. In the first phase of the study pregnant women were studied intensively. Habitual dietary intake of all pregnant women was recorded by the weighing technique with a field worker staying over 3 consecutive days, once in early pregnancy and monthly in the last trimester (Launer et al., 1991). They were asked to come to the project's antenatal clinic at 4-weekly intervals for an obstetric examination and anthropometric measurements (height, weight, skinfold thickness at 4 sites, upper arm circumference). All anthropometric measurements were taken in duplicate according to standard techniques (Weiner & Lourie, 1969). Standardization exercises were done at 3-6-monthly intervals (Habicht, 1973). In a 10% random sample (n = 72) women's activities were recorded chronologically over a 12h period using a digital watch. Only a subsample of lactating women was covered for recording of food consumption (n = 78) and physical activities (n = 108).

General background

The two study villages were located in an area with two rain periods and moderate seasonality in food availability (Ferro-Luzzi, Pastore & Sette, 1987). The annual range in mean energy intake was 1500-1700 kcal per day (6.37.1 MJ/day) for pregnant women (Kardjati et al., 1988; Launer et al., 1991). The energy intake of lactating women was about 200 kcal (0.84 MJ) higher (unpublished data).

As in any subsistence economy, women are housewives and productive labourers. The activity records indicate that women were engaged in light or at most moderate activities. Irrespective of physiological state only 5-15% of the day (1-3 h) was spent on strenuous work, such as working in the fields, selling fish at the market and fetching water (unpublished data). The level of physical activity would thus correspond to 1.5-1.7 x BMR (FAD/WHO/UNU, 1985).

Study population

For the assessment of the functional significance of BMI during reproduction, data from women living in the two villages are used. They had given birth to a liveborn singleton baby in the period September 1982-December 1989, and involved 982 women and 1783 newborns. The coverage of birth weights was 88%; of maternal height 90%, pre-pregnant weight 65% and postpartum weight at 4-7 weeks 61%. Missing data were mainly due to a lapse in data collection between the two phases and during the phasingin of data collection procedures.

Table 1. Pre-pregnant body mass index (BMI) by pre-pregnant weight and height categories: mean (SD)