Immature oocyte syndrome: ovulation triggering with combined hCG /GnRH agonist or increased doses of hCG?

Abstract

Immature Oocyte Syndrome (IOS) is usually defined by < 70 % of retrieved metaphase II (MII) oocytes in IVF cycle. It can be explained by intrinsic abnormalities or inadequate stimulation. Ovulation triggering is critical for resumption of meiosis. As both LH and FSH are needed for oocyte final maturation in natural cycle, it has been suggested to trigger ovulation with a combination of hCG and GnRH agonist in case of oocyte immaturity. In this study we evaluated the interest of 2 strategies of ovulation triggering (dual trigger with combined hCG/GnRH agonist versus increased doses of hCG alone) in women with previous IOS.