ABSTRACT
PIP: Although there is general agreement that asynchrony of the endometrial mucosa is the mechanism by which implantation is inhibited among IUD users, there is a lack of consensus as to whether the type of asynchronism is a delayed or accelerated maturation. To detect the effect of IUDs on dating of the endometrial mucosa, endometrial biopsies were taken from 50 asymptomatic Lippes loop users on days 16, 20, and 24 of the menstrual cycle. The cases, who ranged in age from 20-40, all had regular cycles. A discrepancy of 2 or more days was categorized as representing endometrial asynchrony. On day 16, 29 cases (58%) showed a delayed maturation ranging from 2-12 days. By day 20, delayed maturation was noted in 40 cases (80%), with a range in delay from 2-10 days. On day 24, 44 cases (88%) showed endometrial asynchrony from 2-8 days. The incidence of endometrial asynchrony observed in this series is considerably higher than that obtained in previous studies. This may reflect differences in definition and in dating time and methods. Some studies have considered 3 or more days of delay to be significant. Another study took specimens during the proliferative phase of the menstrual cycle, at which time accurate dating is not possible. The results from the present series suggest that endometrial asynchrony in for form of delayed maturation may be a contraceptive factor. However, further research involving larger numbers of cases is needed.^ieng
