(N Engl J Med 2015; 373:1230-1240 September 24,2015)
The most important adverse effect to be avoided when using "fertility drugs" is the generation of multiple pregnancy, as this type of pregnancy is associated with much higher rates of complications, and, unfortunately pregnancy loss.
When IVF treatment is used in Australia, because we almost always transfer a single embryo, the risks of multiple pregnancy are very low.
In the United states, 20% of triplet births are natural conceptions, 60% are from Ovulation induction, and 20% are from IVF treatment and multiple embryo transfer. If we compare 1960 to 2011, in the U.S., despite the birth rate going down , there were five times more triplet births in 2011.
The Multiple birth rate from IVF in Australia is 5% of pregnancies, compared to 31.6% in the United States.
In the AMIGOS study, the pregnancy and live birth rates were quite good, but the multiple birth rates were dramatically high, with one third of pregnancies in women using FSH being multiple, and 10% of pregnancies being triplets!
Even women using Letrozole in this study had a 13% twin pregnancy rate, emphasising the need for care with ovulation induction.
The other issue which this study raised, in Russell's opinion, was the importance of carefully assessing women with "unknown" or idiopathic infertility, as many will have endometriosis, tubal issues or lifestyle factors contributing to their fertility problems.
There are a small group of couples with "idiopathic" infertility who have an egg and sperm binding problem as a causative factor.
Finally, there is the issue as to what to do about actual unknown infertility.
The best options, in our opinion are:
• waiting a further period of time for natural conception, if the woman's age,
• the couple's life plans permit,
• moving straight to IVF with a single embryo transfer.
In situations of advancing age, IVF has the strong benefit of often providing fertility preservation in the form of vitrification (freezing) of spare embryos for use at a later time.
~ Dr Russell Dalton