Here at Dominion Fertility we are really doing our best to reduce the number of twin pregnancies. Seriously. No, I really mean it. Recently we were commended by the CDC for our exceptionally high rate of single embryos transfers.
Usually we urge patients to pursue elective single embryo transfer (eSET) if it is their first cycle of stimulated IVF and they are < 35 years old and embryo quality is very good to excellent. However, as many patients/couples view twins as an acceptable and even desirable outcome it is hard to sell eSET to many of them.
In this case, the couple had been through a lot but was open to eSET. I was very happy when I saw the first beta level but figured it was just a really healthy singleton. Then came the first pregnancy sonogram and I saw a single gestational sac with two yolk sacs. Oh well. Follow-up sonograms demonstrated that the twins were not in a single sac which would have made the pregnancy a much higher risk endeavor. Still identical twins were not on our radar screen as the rate of identical twinning is usually only 1-2%.
So in spite of eSET, not all pregnancies will be singletons but as I really can't transfer less than one embryo we are stuck with a small risk of twins no matter what....
Still, as I tell my patients at the time of ET, I don't babysit and I don't change diapers anymore..