Published online by Cambridge University Press: 01 February 2010
Parallel to the great progress achieved during the last two decades in the therapeutic induction of ovulation was an increasing incidence of the two main complications associated with this kind of treatment, namely, ovarian hyperstimulation syndrome (OHSS) and multiple pregnancies.Schenker et al. 1981
All multiple births are associated with significant neonatal, maternal and family morbidity, but this is particularly so for triplet and higher-order multiple births (HOMB). Ovulation induction (OI), outside of in-vitro fertilization (IVF), is estimated to be responsible for 20% of twins, 40% of triplets and 70% of infants live born in quadruplet and higher-order deliveries in Western nations. On average 10% of births resulting from clomiphene (CC) will be twins, and less than 1% of births will be triplets and HOMB. These figures increase to 20% and 8% respectively for births resulting from gonadotropins. For younger patients who are high responders, the incidence of triplet and higher-order pregnancies (HOMP) can be 20%. Nearly all HOMB due to OI with gonadotropins in controlled ovarian hyperstimulation (COH) protocols might have been prevented by use of lower doses of gonadotropins, with very little reduction in the number of patients able to conceive. The majority of women who require OI will be able to become pregnant within 3-6 cycles of single or double follicular development using oral drugs or low-dose gonadotropins, with a 10% chance of twins and less than a 1% chance of HOMB.