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.