Gonadotropin agonist administrations have been used successfully to stimulate ovarian follicular development not only in ovulatory dysfuction but also in normal ovulatory women for the purpose of in vitro fertilization (IVF) programs.
Although hCG is similar in action as LH, hCG differs from LH by its much longer circulating half life and biological effect. Therefore hCG administration is associated with a sustained leuteotropic effect, multiple corpora lutea development and
supraphysiological serum E2 and P4 levels throughout luteal phase. These effects can be implicated in implantation failure, early embryo loss and also cause of development of severe OHSS.
Using GnRH-a for maturation of the final stage of the follicles and triggering ovulation ovulation effectively induce preovulatory LH surge and decrease to normal level, similar as natural ovulatory cycles. GnRH-a could be used in the high risk
group of
severe OHSS, because GnRH-a provide a more physiological ovulatory stimulus.
From October 1991 to July 1992, single dose of GnRH-a(decapeptyl, 0.1mg) subcutaneously was administered to 26 cycles(21 patients) with normal responder group for triggering the final maturation of oocytes. And 16 cycles(11 patients) with high
risk
for
OHSS groups. As a control group, 10,000IU hCG was intramuscularly administered to 24 cycles(26 patients) for triggering the final maturation oocytes.
@ES The results were as follows:
@EN 1. In control group and normal responder group of GnRH-a were comparble with no significant difference between various clinical parameters.
2. Serum E2 and number of follicles were significant difference on the day of hCG injection or GnRH- a in control group and high responders of GnRH-a (P<0.001).
3. 6 mild, 2 moderate and one severe OHSS were occurred in hCG group, on the other hand only one moderate OHSS was occurred in high responder group of GnRH-a .
4. Serum E2 concentration was significantly lower in both GnRH-a group than in control group in ET day (+4 days) and midluteal day(+9 days) (P<0.001, P<0.005)
5. GnRH-a triggered LH and FSH surge effectively, and increased LH was normalized within 48 hours. In control group, hCG triggered LH surge, and last 7 days at least.
In conclusion, CnRH-a is provide not only a more physiological LH surge than hCG, but also an adequate hormonal levels in the midluteal phase. We suggest that the use of GnRH-a in patients at high risk of OHSS could prevent OHSS effective.
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