Female age, the length of involuntary infertility prior to investigation and fertility outcome

The objectives of this study were two-fold: firstly to determine whether female age exerts an influence on the fertility outcome of couples attending an infertility clinic, independent of demographic and clinical details; and secondly to examine the relationship between the length of involuntary infertility prior to investigation and the subsequent chance of conception. Seven-hundred-and-thirty-one subjects whose partner did not have azoospermia were recruited to the study. Female age ranged from 20 to 46 (mean = 31.1). The range of involuntary infertility prior to investigation was 12-216 (mean = 62) months. One-hundred-and-twenty-four women conceived. The following variables achieved the 5% level of significance when a stepwise analysis was performed on all cases; the concentration of spermatozoa exhibiting slow or sluggish linear or non-linear motility (chi 2(1) = 17.57, P less than 0.0001, RR = 1.67 per 50 x 10(6)), female age (chi 2(1) = 12.44, P = 0.0004, RR = 0.92 per annum), tubal status (chi 2(1) = 12.22, P = 0.0005, RR = 2.15), length of infertility before investigation (chi 2(1) = 11.22, P = 0.0008, RR = 0.87 per annum) and past paternity (chi 2(1) = 8.43, P = 0.0037, RR = 1.81). Female age was found to be positively correlated with the incidence and severity of ovulatory dysfunction, tubal occlusive disease, pelvic adhesions and endometriosis. Where the female partner was 'normal' on investigation, all conceptions were independent of treatment to either partner.(ABSTRACT TRUNCATED AT 250 WORDS)