MODELLING ANOVULATORY INFERTILITY AMONG WOMEN WITH POLYCYSTIC OVARY SYNDROME IN BENIN CITY, NIGERIA

Abstract

Ovulatory dysfunction is one of the prominent causes of infertility among women and very large proportion of women experiencing this has polycystic ovary syndrome (PCOS). The study of the conditional effect between moderator variables and focal predictors of anovulatory infertility among women with polycystic ovary syndrome helps to prevent or control infertility. This study examines the factors associated with anovulatory infertility among women with polycystic ovary syndrome and evaluates the moderator factors in the relationship between selected factors and anovulatory infertility among women with polycystic ovary syndrome in Benin City, Nigeria. A total of 336 women of reproductive age l 8-40years were used in the study. The anovulatory infertile women with polycystic ovary syndrome and women attending fertility clinics having nonnal ovulation were almost equal in size for the case and control cohorts. Ovulatory dysfunction was defined as a history of less than eight cycles in a year, or menstrual cycles less than 26 d or more than 35 d in length; or a d 21-24 (midluteal) P4 level < 4 ng/ml in women with regular menstrual cycle. Regular menstrual cycle was defined as 26 -34 din length. The presence of PCOS in these consecutive women was defined using NIH criteria. Under the NIH criteria, PCOS was defined as the combination of ovulatory dysfunction together with clinical and/or biochemical hyperandrogenism and the exclusion of other related disorders such as hyperprolactinemia and thyroid disorders. Conditional Logistic regression was used to examine factor of anovulatory infertility using age (years) as matched or grouping variable. However, Moderated Regression was used to model the conditional effect between moderator variables and focal predictors of anovulatory infertility among women with polycystic ovary syndrome. The study revealed the following factors of anovulatory infertility after adjusting for confounders; follicle stimulating hormone, luteinizing hormone, day·21 progesterone, high sensitive C - reactive protein and fasting glucose. In examining the effect of moderator variables in the relationship between selected factors of anovulatory infertility, Johnson-Neyman technique revealed that high sensitive C -reactive protein has significant interaction with high density lipoprotein-cholesterol, mean blood pressure, prolactin and fasting insulin. In addition, day-21 progesterone has significant interaction with fasting insulin, homeostasis model assessment of insulin resistance, uric acid and body mass index. This study has immensely examined key focal predictors of anovulatory infertility among women with PCOS and the moderators of the relationship between focal predictors and anovulatory infertility. The implication of this knowledge is useful in health policy, medical education, practice and research of women at the reproductive age in checkmating anovulatory infertility.