Female sex selection using clomiphene citrate and albumin separation of human sperm.

BACKGROUND This study was undertaken to assess whether the use of clomiphene citrate in conjunction with albumin-separated sperm would alter the sex ratio (expressed as the proportion of males) towards females and, if so, whether this skewing was due solely to the induction of ovulation. METHODS The sex ratios of 184 single and 42 twin births at five assisted reproduction biology clinics were determined. The normal approximation to the binomial distribution was used to determine significant differences between these sex ratios and the established sex ratios for single, twin and combined (single and twin) non- and ovulation-induced births. RESULTS The non-ovulation-induced sex ratios for singletons (51.4%) and twins (50.2%) were greater than the treatment singleton (27.7%; P < 0.001) and twin (33.3%; P < 0.01) sex ratios respectively. Correspondingly, the non-induced sex ratio for combined births (51.4%) was greater than the treatment sex ratio (28.8%; P < 0.001). The previously established induced singleton and twin sex ratios (48.1%) were lower than the non-induced sex ratio (51.4%), but higher than the treatment singleton (27.7%; P < 0.001) or twin (33.3%; P < 0.03) sex ratios. The ovulation-induced combined ratio (48.1%) was less than the non-induced combined (51.4%) sex ratio, although greater than the treatment combined sex ratio (28.8%; P < 0.001). CONCLUSION Clomiphene citrate in conjunction with albumin-separated sperm decreased the sex ratio; a reduction that was not exclusively due to induction of ovulation.