Dynamics of birth spacing in Pakistan.

The data of the Population Labour Force and Migration (PLM) Survey of 1979-1980 was analyzed in order to study spacing between births as well as differentials in urban and rural areas, differentials by age at marriage, urbanization, education, work pattern, and contraceptive use. The median intervals from PLM Survey of 1979-80 and Pakistan Fertility Survey (PFS) of 1975 birth histories were compared by urban and rural residence for each parity in order to analyze trends in birth spacing. Findings indicate only a slight increase in child spacing, the 1st birth interval of urban females has increased consistently by 1 month from 1st parity to 4th parity according to PLM 1979-80. Urban women had shorter spacing of births than rural females in both surveys. In addition, the Pakistan Demographic Survey of 1985-86 showed that the medium of the 1st birth interval declined to 18.09 months compared to the 22.46 months of PLM. Women in urban areas had a higher rate of fertility than women in rural areas where the interval between marriage and 1st birth increased. Urban females also had shorter duration of breastfeeding and tended to have shorter median birth intervals at higher ages at marriage. Longer intervals were attributed to subfecundity or delayed cohabitation. In rural areas women do not space their births deliberately. The medium birth interval of women in urban centers was 4 months shorter than those for rural females with the same education increasing by 7 months in case of no female education. Educated females in major urban areas achieved their family size faster than women residing in other urban and rural areas. Educated urban females with high parity (4+) had longer intervals due to greater contraceptive use and a diminished desire to have more children. In the urban areas of Punjab and Sind longer birth spacing was recorded than in the rural areas but differences disappeared after the 2nd parity. Obviously, women engaged in economic activity want to complete their family size earlier, thus the birth interval is shorter. Among contraceptive users, ever users had shorter median intervals, as this small group was more educated and wanted to complete family size in a short time. There are certain associations between variables, but the impact of changes of birth spacing on marital fertility in inconclusive.