2010년 미국불임학회(ASRM) P-85 The pregnancy rate is significantly increased when the duration of progesterone supplementation and embryonic age are synchronized in day 3 frozen-thawed embryo transfer. (동결란 이식시 프로게스테론 보충과 수정란의 성장속도를 이식일에 맞추어서 시행하게 되면 임신율 향상을 가져온다.)

E.M. Cha1, S.G. Kim1, J.H. Lee1, I.H. Park1, G.H. Jeon2 , K.H. Lee1
1Mamapapa&baby Hospital, Infertility Lab, Ulsan, Korea South
2 Department of OBGY, college of medicine, Inje university Haeundae paik hospital, Korea South

OBJECTIVE

To evaluate the difference of pregnancy rate according to the duration of progesterone(P) supplementation on day 3 Frozen-Thawed embryo transfer(FET).

DESIGN

Retrospective study

MATERIALS AND METHODS

We analyzed 165 cycles from patients underwent frozen thawed embryo transfer from Jan 2009 to March 2010. All patients received high dose of estradiol valerate(6mg) to prevent premature LH surge, starting from day 1 or 2 of the menstrual cycle without pituitary down regulation. when the endometrium was developed sufficiently (≥8mm) detected by ultrasound examination, patients were given 50-100mg of IM P in oil daily until serum β-hCG test was performed. Embryos were frozen and thawed on day 3 using a vitrification protocol. We divided our data into two groups based on the duration of P supplementation.
In group 1 (n=35) progesterone was administered 3 days prior to FET day.
In group 2 (n=130) progesterone was administered 4 days prior to FET day.
FETs were performed by same physician on the same day of embryo thawed. Pregnancy identified through detection of G-sac in transvaginal ultrasound examination.

RESULTS

There was no difference between both groups in patient age (33.70 vs. 34.27), the mean number of transferred embryo (2.31 vs. 2.61), the mean number of cryopreserved embryo (8.19 vs. 7.63), and embryo quality. Both groups are in acceptable range of implantation window. However, the pregnancy rate was significantly higher in group 1 (37.1%) than group 2 (23.8%).

CONCLUSION

Progesterone induces morphological and biochemical changes in the endometrium for “implantation window” and after. But the precise duration of P supplementation for FET is still a matter of debate. Our study shows that pregnancy potential is higher when day 3 embryo is transferred on the same day of P supplementation. It seems that extended duration of P supplenmentation than embryonic age doesn’t induce a better outcome in pregnancy rate. Thus we emphasize that synchrony between endometrial and embryonic development is a crucial factor for not missing implantation window.