Levels and trends in post-partum amenorrhoea, breast-feeding and birth intervals in Matlab, Bangladesh: 1978-1989.

This study examines the trends in and determinants of length of postpartum amenorrhea during 1978-90 in Bangladesh. Data are obtained from the Matlab project. The sample comprises 6000 women per cohort for cohorts born in two year periods during 1978-80 and 1988-89. Reproductive and lactation records are available for up to 36 months following the birth of the index child. Findings indicate that the duration of postpartum amenorrhea is around 13 months for births during 1978-83. The median duration is 13.5 months for the birth cohort for 1982-83 and 9.4 months for the birth cohort for 1988-89. For 1989 alone the median duration is a further decline to 8.6 months. The seven year decline amounts to a 36% reduction. Findings indicate that age and duration of postpartum amenorrhea are positively related. All age groups show a decline in median duration. The shorter median durations occur among women with fewer than two living children and higher levels of education. Duration of breast feeding peaks in 1984-85 at 34.3 months and then declines to 30.7 months in 1986-87. Full breast feeding duration declines from around 6 months for cohorts 1978-79 to cohorts 1982-88 to 5.2 months in 1986-87 and lags behind durations of postpartum amenorrhea. Full breast feeding declines occur after the 1982-83 cohort among mothers with higher education and after the 1984-85 cohort for uneducated and less educated women. Age patterns of breast feeding women are inconsistent. The oldest mothers have the shortest breast feeding durations. The youngest cohorts show a decreasing trend. Breast feeding durations increase with an increase in the number of living children. However another trend shows initial increases in duration and then declines regardless of the number of living children. The suggestion is that full breast feeding may be important in determining the length of postpartum amenorrhea duration. Contraceptive use increases from 24% in 1977 to 39% in 1984. Median birth intervals increase from 38.7 to 48.8 months and increases pertain to all age and parity groups. Malnutrition is considered to be unrelated to postpartum amenorrhea periods. The trend is clearly reflective of declining postpartum amenorrhea duration, but the nature of the impact of breast feeding or contraceptive use is not clear.