Short birth intervals: the experience of Bangladeshi immigrants to the United Kingdom, 1974 through 1984.

Linked maternity data were used to calculate birth intervals from records of 7129 consecutive singleton births to Bangladeshi mothers who delivered in the London borough of Tower Hamlets from 1974 through 1984. During this period, there was active migration of women from Bangladesh, the majority coming to the United Kingdom as brides or young wives. Risk of a subsequent birth was calculated using life tables, and results were compared to national data from Bangladesh and the United Kingdom. The risk of a subsequent birth within 12 and 18 months for Bangladeshi women was twice that reported nationally for women in Bangladesh or in the United Kingdom, despite a demonstrable underestimation inherent in the method. The risk of short birth intervals was lower in the first 5 years than in the later years covered by the investigation. Short intervals stress maternal and infant health and are preventable. Possible explanations for the unusual excess of very short birth intervals include: (1) the wide availability of artificial milk in a community that has traditionally used breast-feeding as the main method of spacing pregnancies and (2) confusion regarding appropriate postnatal contraception in a young, healthy married population.