Purpose:
The aim of the study was to find whether inferences to the possible success of natural IVF/ICSI cycles could be drawn from the estradiol (E
2
) pattern.
Methods:
Sixty-eight women who underwent oocyte recovery in 98 natural cycles were recruited for the study. Daily serum E2 was measured in the preovulatory phase (–3 to +2 day). The E
2
pattern was compared among four groups: Group A, unsuccessful egg retrieval; Group B, no fertilization; Group C, no implantation; and Group D, implantation.
Results:
There was no difference in mean E
2
levels between groups. Only the ratio of E
2
on day +1/E
2
on day 0 was significantly lower in conception cycles in comparison with nonconception cycles. In cycles with a decreased E
2
level on day +1, only the implantation rate was significantlly higher in comparison with cycles with an increasing E
2
level.
Conclusions:
From the E
2
pattern it is possible to make inferences about the likelihood of implantation but not the fertilization or oocyte recovery success.
estradiol pattern - implantation - natural cycles - in vitro fertilization