IVF has a bad reputation for producing multiple pregnancies including twins, triplets or more. These pregnancies are risky because they often mean having a caesarean section which is three times more dangerous for the mother than vaginal birth. Twins and triplets tend to be lower birth weights, more prone to premature delivery and other complications of pregnancy which put them at risk of a variety of health problems.
Medical professionals are therefore keen to avoid multiple pregnancies.
A new IVF technique called Single Blastocyst Transfer is set to make IVF induced pregnancy safer. Usually, when invitro fertilisation occurs, the embryologist will transfer several embryos to the womb in the hope that they will implant. The American Society For Reproductive Medicine recommends the transfer of at least two embryos in a treatment, preferably three or more. (In the UK, only two embryos can be implanted at any one time, and not more).
With single blastocyst transfer, just one fertilised embryo is put into the womb.
A study was conducted at Stanford University School of Medicine, involving 45 infertile women, aged 35 years and over. Single blastocyst transfer was performed on all of them. 28 of them concieved (62.2%), and of those, 23 had pregnancies that survived beyond the first trimester (51.1%).
Dr. Amin Milki, who headed the study, said it was an excellent pregnancy rate. However, he failed to say how many live births resulted from these pregnancies.
He said half his patients already had one child and wanted only one more, while others wanted to avoid all the health problems associated with multiple pregnancy.
This offers reassurance that a woman can still expect a good pregnancy rate without gambling with twins," he added,' the findings demonstrate a clear role for the procedure in older IVF patients.
He believes this is good news for women who only want one child.
"Although these results represent a selected group of patients, we believe that they should serve as encouragement to patients and providers who are considering single blastocyst transfer.'
On the downside, women over the age of 35 have poorer quality eggs and so are less able to produce healthy embryos and they have less chance of conceiving than a younger woman, so only using a single embryo for transfer can reduce their chances of getting pregnant at all. The pros and cons of the treatment should be weighed before a course of action is decided upon. It may be for some women that the transfer of two or more embryos would be more effective.
Source: mednews.stanford.edu/
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