Introduction:
GnRH
agonist (GnRH-a) addition to the luteal support scheme in ICSI/IVF-embryo transfer
(ET) cycles was shown to significantly increase pregnancy and live birth rates.
There are no data in the literature regarding the effect of luteal GnRH-a administration
in natural frozen-thawed cleavage-stage embryo transfer cycles (NC-FET).
Aim:
To examine the effect of luteal GnRH-a addition in NC-FET on pregnancy rates.
Material
& Methods: 38 consecutive women underwent 42 NC-FET.
ET of at least 2 embryos was carried out 3 days after detection of the
endogenous LH surge.
All patients were treated with 4 injections of 2,500 I.U. hCG every 3 days
starting on the day of ET. Patients were
randomly assigned to receive a single injection of GnRH-a 3 days following ET
(triptorelin acetate 0.1mg, n=20 cycles) or none (n=22 cycles).
Results: The two groups did not differ in
mean age, gravidity, parity, BMI, cycle number, maximal endometrial thickness
and estradiol levels, number of embryo transferred per patient, freezing type
and embryo quality. Administration of GnRH-a led to a
significant increase of pregnancy rate compared to standard luteal support (55%
versus 18.2% respectively, P=0.023), increased clinical pregnancy rate per ET
(45% versus 9.1%, P=0.022) and increased implantation rate (22.4% versus 4%
respectively, P=0.036). A multivariable logistic regression analysis showed a
single significant predictor for pregnancy, namely luteal GnRH-a administration
(OR 8.4, CI = 1.5-46.8, P=0.015).
Conclusion(s):
Luteal-phase GnRH-a administration significantly enhances
pregnancy rates in NC-FET, possibly by a combination of effects on the embryo,
endometrium and the corpus luteum.
