Predictors of Spontaneous Conception Following Myomectomy among Women with Infertility at Federal Medical Centre Yenagoa, Nigeria

Background: Uterine fibroid or leiomyoma (myoma) is the commonest uterine neoplasm in women, and it has been associated with infertility. Though it’s not regarded as a direct cause, surgical removal (myomectomy) has been reported to increase the spontaneous conception rate in women with infertility.

Objective: The objective of this study was to determine the factors associated with conception after myomectomy in women with infertility. It would determine the pregnancy rate, demographic, and surgical factors (pre and postoperative factors).

Materials and Methods: This was a retrospective observational study of 107 women who had myomectomy during the study period, out of these, 68 were done for infertility. The case notes of these women were retrieved, and information related to demographic factors obtained was: maternal age, parity, address, tribe, educational level, and occupation. The preoperative surgical factors obtained were previous history of myomectomy, indication for myomectomy, the size, number and location of myomas, and the caliber of the surgeon. Postoperative surgical data collected include conception, interval between myomectomy and conception, pregnancy outcome, mode of delivery, and fetal sex and birth weight. Categorical variables were compared with chi square and odds ratio, and the degree of association for quantitative variables was determined using Pearson’s correlation coefficient. Predictor variables were determined using simple logistic regression, and multivariate analysis.

Results: The infertility rate among the women who had myomectomy was 63.6%, the conception rate was 14.7%, and the mean myomectomy to pregnancy interval was 9.20 ± 1.24 months. The factors that favor conception were: younger women P = 0.003, uterine size ≤ 16 weeks odds ratio = 3.50(0.14, 84.20), high parity (p = 0.002), solitary fibroid odd ratio = 2.65(0.44, 16.04), tertiary education P = 0.0001 and surgery by consultants P = 0.004. Others were absence of submucous myomas, and pelvic pathology at laparotomy. Using multivariate analysis, the most significant predictors for conception were age and parity, accounting for 10.7%, and all the factors put together could only explain 36.5%.

Conclusion: The conception rate following myomectomy in Yenagoa was relatively low, and the most important predictors were maternal age and parity. The bulk of the factors (65.5%) that determine conception are outside the scope of our study; these could be male factor infertility, factors within the tubal lumen, unidentified uterine synechia, and ovarian failure.