Doctors treating infertility due to failure to ovulate should rely exclusively on IVF.
That is the conclusion of US researchers who examined the use of drugs in 1494 infertile women. They found that drug treatment for this group resulted in 441 births: 314 single babies, 88 sets of twins, 22 triplets, 10 quadruplets, five quintuplets and two sextuplets.
Apart from a less than 30 per cent success rate, giving high doses of fertility drugs carries considerable risks, including multiple unwanted babies, who often have poor health and a greatly reduced chance of survival. It can also profoundly disrupt a woman's hormonal balance and threaten her own health.
The math is simple. The higher the dose of drugs, the greater the number of follicles stimulated to release eggs at one time. While doctors understand the mechanism by which this happens, they have no means of controlling the way egg producing follicles respond to drug treatment.
High doses of fertility drugs are often given to infertile women because low doses do not increase the chances of conceiving. IVF, by comparison, has around the same success rate without the potential adverse effects (N Engl J Med, 2000; 343: 2-7).