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Do twins born after IVF have a higher risk of health problems? - The Guardian

(21 May 2009)

Twins conceived through in vitro fertilisation (IVF) and similar treatments are more likely to need neonatal intensive care and to be hospitalised in their first three years than naturally conceived twins, according to a new study.

What do we know already? About 1 in 7 couples in the UK have difficulty conceiving at some time and seek specialist fertility treatment. Many have IVF or another form of assisted reproductive technology (called ART). These procedures involve harvesting eggs from a woman's ovaries, fertilising them in the laboratory, and then transferring the embryo back into the woman's womb or fallopian tubes. In the UK, about 1 in 4 women have twins after conceiving through IVF and similar treatments. This happens when doctors use more than one embryo to increase the likelihood that the procedure will work. In general, twins have a higher risk of problems such as low birth weight and premature delivery than singleton babies, regardless of how they were conceived. But until now researchers haven't known whether twins born after fertility treatment such as IVF have an even higher risk of health problems. To explore this issue, researchers have now done a large study looking at the post-birth care and hospitalisations of twins born in Western Australia between 1994 and 2000. What does the new study say? The researchers compared twins born through IVF and similar treatments with non-identical twins conceived naturally. They didn't include identical twins because twins born as a result of IVF are usually non-identical and the researchers wanted to compare like with like. Using government databases, researchers gathered information on 700 babies born as a result of IVF and similar treatments and 1,240 babies conceived naturally. When comparing these groups, they took into account several things known to increase the chance of problems at birth or soon after. For example, women who have fertility treatments tend to be older, which can increase the risk of premature delivery and other problems. After making adjustments for these factors, the researchers found that twins born after IVF and similar treatments: * Stayed longer in hospital than other twins at the time of their birth (an average of 12 days, compared with eight days) * Had about a two-thirds higher risk of being admitted to neonatal intensive care * Had a two-thirds higher risk of being admitted to hospital in their second year of life. They also had a slightly higher risk of needing hospital care in their first and third years, but the difference was small and could have been down to chance. So is there something about IVF and similar treatments that increases the risk of problems at birth and beyond? Possibly, although other factors may be at work as well. For example, some women may have an underlying problem that makes it difficult for them to conceive and also affects their pregnancy. Also, parents who have a difficult time conceiving may be more anxious about their babies, and more likely to take them to hospital. Even so, these findings should add a new note of caution to discussions between would-be parents and doctors about using more than one embryo during fertility treatment. How reliable are the findings? This study was well done overall, and its results should be fairly reliable. However, the researchers were only able to gather information on hospital treatments. So it's possible that some babies had health problems but were treated elsewhere. Also, the researchers weren't able to track whether women had used any other types of fertility treatments, such as drugs to stimulate the ovaries to produce eggs. Some research has suggested that these treatments might also lead to higher rates of hospital admissions after birth. Where does the study come from? The study was done by researchers in the UK and Australia, and it was funded by a grant from the National Health and Medical Research Council of Australia. It was published in a medical journal called Human Reproduction, which is owned by Oxford University Press. What does this mean for me? If you are thinking about having fertility treatment such as IVF, bear in mind that implanting more than one embryo greatly increases your chance of twins, and twins in general have a higher risk of problems, such as premature delivery. This study now shows that the risk of health problems may be even higher for twins conceived through IVF, and this risk may extend through the first few years of life. What should I do now? Many doctors advise against implanting more than one embryo during IVF and similar treatments, because of the problems associated with multiple births. But, ultimately, the decision is yours. Be sure to talk to your fertility specialist about all the risks and benefits of treatment, so you can make a decision that is right for you. From: Hansen M, Colvin L, Petterson B. Twins born following assisted reproductive technology: perinatal outcomes and admissions to hospital. Human Reproduction. Published online 20 May 2009.

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