Infertility treatments may raise preterm birth risk

Link Couples who conceive through ... IVF or ... ICSI had a higher risk of preterm delivery.

... nearly 8 percent were premature and 1.5 percent were very premature ...

... roughly 5 percent of babies born to fertile mothers were premature, and 0.6 percent were very pre-term ...

... Other forms of fertility treatment ... were not related to the risk of preterm delivery.

[The study only looked at singleton babies, so the findings could not be explained by a higher proportion of twins] ... the findings suggest that something about the IVF and ICSI procedures themselves might raise the odds of preterm birth.

... The fact that other forms of fertility treatment were not linked to preterm delivery suggests that infertility itself is not to blame ...

... Another possibility ... has to do with the "vanishing twin" phenomenon ... these surviving fetuses are at increased risk of preterm delivery and low birth weight ...