Clinical variables influencing the success of IVF ET in the natural cycle

The influence of clinical variables on the results of IVF in 196 unstimulated IVF/ET cycles for female infertility was evaluated. Positive puncture rate was 86%. There were 113 ETs: 68% of 170 natural cycles with oocytes retrieved. The live birth rate was 24% per ET. There were no statistical differences between pregnancy rates per ET between higher (0.60-1.17nmol) and lower (0.40-0.59nmol/l) E-2 concentrations on the day of hCG (30% vs 30%), between early (10-14) and late (16-21 day) aspiration day (25% vs 32%), between smaller (16-18mm) and bigger (19-22mm) follicular diameters on the day of ICG (22% vs 31%), between 28 ETs on 2(nd) and 88 ETs on 4(th) day after oocyte retrieval (18% vs 32%), but there was significant difference (P<0.05) between cycles with thin (6-8mm) versus thick (9-12 mm) endometrium on the day of hCG (20% vs 36%).