Spontaneous abortion and interpregnancy interval

Abstract

Analysis of 8972 pregnancies and 5089 interpregnancy intervals, computer-registered over 12 years at the Haguenau Hospital Maternity Department, showed that the length of interpregnancy interval may be considered as a risk factor in spontaneous abortion; this was still true after other important known risk factors, i.e. maternal age, parity, previous spontaneous abortion and contraceptive practice, had been taken into account. However, separate analysis of pregnancies according to whether they occur more or less than 1 year after contraception (if used) had been stopped showed that the relationship between a long interval and spontaneous abortion was only significant for subfertile women who took longer than 1 year to conceive. This supports the hypothesis that the same mechanism is involved in the aetiologies of spontaneous abortion and of difficulty in conceiving.

PIP: Analysis of 8972 pregnancies and 5089 interpregnancy intervals, computer-registered over 12 years at the Haguenau (France) Hospital Maternity Department, indicated that the length of the interpregnancy interval may be a risk factor in spontaneous abortion. The rate of spontaneous abortion after an interval over 2 years was 9.4% compared with 6.7% after an interval of 6 months or less. The mean interpregnancy interval before a spontaneous abortion was 28.0 months and that before a birth 24.6 months. The risk factors for spontaneous abortion in pregnancy 2 were spontaneous abortion in pregnancy 1, maternal age, parity, and contraception during the year before pregnancy; these factors were also significantly correlated with interpregnancy interval length and spontaneous abortion in pregnancy 2. However, separate analysis of pregnancies according to whether they occurred more or less than 1 year after contraception (if used) had been terminated revealed that the relationship between a long interval and spontaneous abortion was significant only for subfertile women who took more than 1 year to conceive. This supports the hypothesis that the same mechanism is involved in the etiologies of spontaneous abortion and subfertility.