Seasonality of fertility in Matlab, Bangladesh

Abstract

SummaryFrom matched birth and census records in the Matlab area of Bangladesh, monthly fertility rates for the period 1970–74 are studied for seasonal patterns by age and parity. Trigonometric regression techniques are used to summarize and compare the multiple series. Pronounced seasonal patterns are apparent for all age and parity groups. The general fertility rate peaks in December with a seasonal variation of 42% above and below the mean level. For younger women at low parities the peak is in late October, while for older women of higher parity it is in January. The shift progresses linearly with age and parity though the age effect is the more pronounced. A seasonal pattern of fecundability which varies by age group could explain the shift.