Single embryo transfer is one optional part of a fertility treatment, most often IVF (in vitro fertilization). Because the risk of success is lowered when you elect to have only one embryo transferred, the procedure is typically recommended for women who are 35 or younger. However, you may still be able to elect for the single embryo option, so long as you understand the risks and the benefits of the procedure.
The Advantage of Single Embryo
The primary reason to select single embryo transfer over the more common multiple embryo transfer is that your risk for multiple births is significantly decreased. All fertility treatments carry a higher risk for multiple births and the more embryos you have implanted, the greater your risk for multiple births. Carrying multiple children significantly increases the risk for your children to have developmental disorders and also increases the risk to your own health, especially if you're over 35.
The Disadvantage of Single Embryo
However, there is one great disadvantage when it comes to choosing single embryo transfer over multiple embryo transfer, especially when you're over 35. Traditionally, between two and five (or even more) embryos have been transferred at once because most embryos fail to successfully become implanted. (However, when more than one embryo does take against the odds, the result is multiple births.)
Embryo Transfer in Women over 35
Because of decreased fertility past the age of 35, most fertility clinics will recommend at least double embryo transfer for those ages 36 to 37, and triple to quadruple embryo transfer for women ages 38 to 40. Women older than 40 may still be eligible for fertility assistance. If you are determined to be healthy enough for the fertility treatment, your fertility specialist will most likely recommend a high number of embryos to be transferred. If you opt for a single embryo, you'll have a decreased chance of success.
This does not mean that you can't elect to have single embryo transfer, especially since the risk of pregnancy complications due to multiple births is even greater in those over the age of 35. You may not want to have to deal with these potential health complications for yourself and your unborn children, as well as the possibility of partial abortion. Be aware, however, that all fertility treatments have a greater risk for multiple births than traditional pregnancies, due to hormonal treatments; even a single embryo can split into multiple identical children. However, your risk for multiple births will be significantly less with a single embryo.
Candidacy for the Single Embryo Option
Some women who are over 35 may qualify for the single embryo option because of the health of their eggs. If you are under 40 and your fertility specialist determines that your eggs are of good quality and are likely to produce a healthy embryo, she may indicate that transfer of a single embryo is a viable option.
Discuss single embryo transfer with your fertility specialist. If you're healthy and have experienced only minor fertility problems, you may still be eligible for the procedure, especially if you're only a few years older than 35.