Department of Obstetrics and Gynecology, McGill University, Royal Victoria Hospital Montreal, Quebec, Canada
1 Correspondence should be addressed. Email: william.buckett{at}muhc.mcgill.c
Sir,
It is with great interest that we read Dr Orvieto's article Can we eliminate severe ovarian hyperstimulation syndrome? (Orvietto, 2005). Of course, as cases of spontaneous ovarian hyperstimulation syndrome (OHSS) have continued to be reported in the literature since the 1990 s (Ayhan et al., 1996
) and possibly earlier (O'Loughlin and Brookes, 1987
), we will never be able to completely eliminate OHSS.
Nevertheless, Dr Orvietto and his co-workers should be commended on developing a clinical algorithm to reduce the risk of severe OHSS following ovarian stimulation.
The use of GnRH agonists to induce a gonadotrophin surge in the place of hCG is not new (Buckett et al., 1998) and it is wrong to suggest that its use will almost totally eliminate severe OHSS. Reports in the early 1990s (Bentick et al., 1990
; van der Meer et al., 1993
) demonstrated that GnRH agonists do not prevent OHSSeven in non-conception cycles.
We believe that immature oocyte retrieval and in vitro oocyte maturation (IVM) without any ovarian stimulation at all is a more reliable way to reduce the risk of OHSS in women with polycystic ovaries who are at risk and yet maintain a reasonable pregnancy rate (Chian et al., 2000). In women with normal ovulatory ovaries, the combination of natural cycle IVF with IVM (Chian et al., 2004
) will similarly lead to a reduced risk of OHSSeven if GnRH agonists are substituted for hCG in at risk women.
In our experience so far, we have performed over 500 cycles of conventional IVM or natural cycle IVF combined with IVM without any cases of OHSS and have achieved clinical pregnancy rates of 3040% in women aged <40 years of age. The only way to avoid iatrogenic OHSS is to avoid ovarian stimulation.
References
Ayhan A, Tuncer ZS and Aksu AT (1996) Ovarian hyperstimulation syndrome associated with spontaneous pregnancy. Hum Reprod 11, 16001601.[Abstract]
Bentick B, Shaw RW, Iffland CA, Burford G and Bernard A (1990) IVF pregnancy after induction of an endogenous ovulatory gonadotrophin surge using an LHRH agonist nasal spray. Hum Reprod 5, 570572.[Abstract]
Buckett WM, Bentick B and Shaw RW (1998) Induction of the endogenous gonadotrophin surge for oocyte maturation with intra-nasal gonadotrophin-releasing hormone analogue (buserelin): effective minimal dose. Hum Reprod 13, 811814.[Abstract]
Chian RC, Buckett WM, Tulandi T and Tan SL (2000) Prospective randomized study of human chorionic gonadotrophin priming before immature oocyte retrieval from unstimulated women with polycystic ovarian syndrome. Hum Reprod 15, 165170.
Chian RC, Buckett WM, Abdul Jalil AK, Son WY, Sylvestre C, Rao D and Tan SL (2004) Natural-cycle in vitro fertilization combined with in vitro maturation of immature oocytes is a potential approach in infertility treatment. Fertil Steril 82, 16751678.[CrossRef][ISI][Medline]
O'Loughlin J and Brookes CM (1987) Massive multiple theca lutein cysts complicating nonmolar pregnancy. Aust NZ Obstet Gynecol 27, 166168.
Orvietto R (2005) Can we eliminate severe ovarian hyperstimulation syndrome? Hum Reprod 20, 320322.
van der Meer S, Gerris J, Joostens M and Tas B (1993) Triggering of ovulation using a gonadotrophin-releasing hormone agonist does not prevent ovarian hyperstimulation syndrome. Hum Reprod 8, 16281631.[Abstract]
Submitted on February 4, 2005; accepted on March 10, 2005.