Problem: In Japan, marital age and women's age at the first pregnancy are continuing to increase year by year. However, information concerning subsequent live birth rate according to maternal age and number of previous recurrent miscarriages is limited.
Method of study: We studied a total of 1250 unexplained patients suffering two or more consecutive miscarriages. We examined the live birth rate at the first pregnancy and the cumulative success rate for birth of at least one child after examination.
Results: The live birth rate of women in their 40s was 58.1%, which was similar to that of women who were 35-39 years old (58.4%) at the first pregnancy, as found after examination. From logistic regression, women's age and the number of previous miscarriages independently decreased the live birth rate in subsequent pregnancies (p(s)) as well as cumulative pregnancies (p(c)), as follows: logit (p(s)) = 3.964 - 0.0652 x (age) - 0.408 x (previous number of miscarriages), logit(p(c)) = 6.806 - 0.1130 x (age) - 0.514 x (previous number of miscarriages).
Conclusion: The information concerning the live birth rate can be given to each patient before subsequent pregnancy.