Objective: To determine the frequency and effect of premature luteinizing hormone (LH) surges on pregnancy rates in women with regular menstrual cycles.
Design: Retrospective cohort study.
Setting: Assisted Reproductive Technology Program at private medical college.
Patient(s): Regularly menstruating women undergoing frozen embryo transfer (ET).
Intervention(s): Detection of urinary LH surges with an RIA kit during natural-cycle frozen-embryos transfer.
Main outcome measure(s): Incidence of premature LH surges and pregnancy outcomes.
Result(s): Eighty-eight (46.8%) of 188 regularly menstruating women had premature LH surges and 33 (37%) of those 88 had multiple premature LH surges. Pregnancy rates per ET are similar between women with and without premature LH surges.
Conclusion(s): A high percentage of normally cycling women demonstrate premature urinary LH surges without an effect on outcome of frozen-thawed ETs.