May 2008

Eliminating Ovarian Hyperstimulation Syndrome (OHSS) risk in IVF

Ovarian Hyperstimulation Syndrome (OHSS) is the most fearsome complication in IVF treatment cycle. It can result in serious morbidity and occasionally even fatality.

While the use of agonist was first reported in 2000, the study conducted by the Thomson fertility Centre is believed to be the largest in the world. The use of agonist to trigger ovulation is only possible with the antagonist-driven stimulation protocol which is not widely used in Singapore. Existing protocols use mostly hCG (human gonadotrophin) to trigger final oocyte maturation which carries a risk of OHSS. A recent US study showed that the risk of OHSS in existing protocols in high risk patients was 31% (of which 15.6% was moderate to severe).

In a study of 55 high-risk patients conducted by the Thomson Fertility Centre between 2005 and 2007, the findings showed that with the use of agonist to trigger ovulation, there is no risk of OHSS and patients can continue the IVF cycle safely. The scientific paper presented by Dr Cheng Li Chang, Medical Director of Thomson Fertility Centre, at the 2nd Congress of the Asia Pacific Initiative on Reproduction (ASPIRE 2008) recently, garnered the first prize for MERCK SERONO ART YOUNG INVESTIGATORS AWARD.

With the positive findings of this study, patients who experience high follicle production during an IVF cycle need not abandon the cycle after spending a large amount of money on drugs and still retain the same chance of pregnancy in a subsequent frozen cycle.