Study by Matching of the Demographic Impact of an IUD Program: A Preliminary Report

Abstract

A most important question about the IUD program is how much it will contribute to the fertility decline in a population. An earlier report1 of a co-author indicated that the fertility of the intrauterine contraceptive device (IUD) acceptors was 54 per cent higher than that of the average of the married women in Taiwan. The women were also in terms of recent births: their open intervals2 averaged 21 months compared with 37 months for the average of the married women included in the KAP3 survey sample. After the first acceptance, their fertility declined by about 76 per cent compared with only about a five per cent decline among the married women in general. The comparison above, however, overestimates the impact of the IUD because the acceptors had been subjected to a higher demographic pressure and were also selected by a stronger motivation for family limitation. Their fertility would have declined more than married women in general even if there had been no IUD. A strict control group study is not feasible, but one way to estimate the real demographic impact of the IUD is by matching. Taiwan is fortunate in having a unique household registration system from which can easily be obtained not only the names and addresses of married women but also their characteristics such as