Oocyte retrieval timing based on spontaneous luteinizing hormone surge during natural cycle in vitro fertilization treatment

Objective To determine the efficiency of oocyte retrieval (OR) timing based on the occurrence of spontaneous LH surge during natural cycle IVF (ncIVF) treatment. Design Retrospective cohort study. The cohort was divided into five subgroups according to the presumed stage of spontaneous LH surge on scheduling day (1A: before onset; 1B: surge start; 2: ascending slope; 3: peak; and 4: descending slope). Setting Private infertility clinic. Patient(s) Three hundred sixty-five infertile patients who underwent 1,138 ncIVF treatment cycles during 2008–2011. Intervention(s) Drug-free ncIVF treatment. Main Outcome Measure(s) Rate of successfully retrieved, fertilized oocytes, cleaved embryos, and live births per scheduled oocyte retrieval. Result(s) In 61% of the cycles OR was scheduled before or just at the start of the LH surge (groups 1A–1B), whereas in the remaining cases it was scheduled after the surge had already started (groups 2–4). The proportion of cycles with successfully recovered (range, 71%–86%), inseminated (range, 61%–78%), fertilized oocytes (range, 47%–68%), cleaved embryos (range, 45%–66%), and live births (range, 4.1%–9.2%) was not significantly different among subgroups. Conclusion(s) In ncIVF treatment OR timing based on the occurrence of spontaneous LH surge is feasible, yielding acceptable oocyte recovery, fertilization, and embryo cleavage rates. This strategy combined with a rapid and low-risk OR procedure permits the management of a large ncIVF program on a 7-days-per-week basis within working hours.