The main problem, however, is that for each new frozen transfer, she must wait three to eight more weeks, take more estrogen and progesterone supplements to thicken the lining of her uterus (to help embryos implant) and pay $2,500 to $4,500 in addition to the cost of the first cycle, which ranges from $12,000 to $15,000 without insurance coverage. (It's worth mentioning that some doctors offer package pricing.) That's not to mention the angst factor. If a woman has been trying for years to get pregnant, the last thing she wants to hear is another, "You have a negative pregnancy result" any more times than she has to.
The typical IVF patient doesn't want to waste any time getting pregnant, and she usually wants more than one child, explains Norbert Gleicher, medical director at the Center for Human Reproduction in New York City. "The majority of my patients want twins," he says. "The older they are, the more they want them. And the longer they've been trying to get pregnant, the more they want them."
Yet the increasing number of doctors who advocate single embryo transfers say their goal is to avoid unnecessarily risky twin pregnancies, which account for 16 to 33 percent of IVF pregnancies, according to 2009 figures from the Society for Assisted Reproductive Technology. (By contrast, triplet IVF pregnancies, which are particularly dangerous, make up 1.5 percent of IFV pregnancies. The chances of conceiving twins naturally is about 1 in 89 pregnancies.) These doctors tend to point out that mothers carrying twins suffer from more hypertension, gestational diabetes, heart stress, and placental problems than those pregnant with singletons, and twin babies have higher rates of severe premature birth, handicaps, low birth weight, and infant mortality.
Those risks would make twins seem like a terrible idea, if they applied to IVF patients, and Gleicher insists that they don't.
He says that IVF patients actually contend with a much lower set of risks than do other mothers of multiples, since they're closely monitored and managed from the moment of conception. Twin mothers in the general population, by contrast, might not know they are having twins until later in their pregnancies and don't receive proper prenatal care. Gleicher recently co-authored a paper in Fertility and Sterility arguing that undergoing two singleton pregnancies carries as much risk as one twin pregnancy.
Finally, fertility doctors shouldn't dissuade a patient from trying for twins for the simple reason that they can't guarantee she will be able to get pregnant a second time, when she will be that much older. For many patients short on time and money, twins are a blessing. Current guidelines give women a good chance of getting them without incurring a high risk of getting pregnant with more than two. If that approach allows more women to get pregnant at all than from doling out embryos one by one, it's not worth fixing a system that appears to be working just fine.