DURHAM, N.C. -- One cycle of in vitro fertilization (IVF) in the United States can cost more than $12,000, leading many women to have several embryos implanted at once to improve their chances of getting pregnant on the first try.

But the practice also raises the risk of multiple births, which can result in premature deliveries and other complications that can be life-threatening to both mothers and babies.

In a study published in the December 2016 issue of the journal Obstetrics & Gynecology, researchers at Duke Health found that fewer multiple births seem to occur in states where health insurance companies are required to cover the costs of IVF treatments.

“IVF is very expensive and so patients who don’t have insurance coverage and are paying out of pocket have a large incentive to try and minimize the number of treatment cycles they endure to try and have a baby,” said study author Jennifer Eaton, M.D., medical director of Assisted Reproductive Technologies at the Duke Fertility Center. “Often, those patients request transfer of more than one embryo.”

Eaton and her colleagues analyzed patient data collected by the Society for Assisted Reproductive Technology (SART) between 2007 and 2011. Data were only considered for states that have more than one clinic that performs IVF. Of the 40 states that meet that criterion, six mandate that insurers provide coverage for at least one IVF cycle: Connecticut, Hawaii, Illinois, Massachusetts, Maryland, and New Jersey.

Data were included for patients between the ages of 20 and 42 undergoing their first IVF cycle in their state of residence and using their own eggs.

Researchers found that patients in states with mandated IVF coverage had fewer embryos implanted per cycle and were more than twice as likely to have elective single embryo transfer -- a practice recommended by SART when appropriate. Both groups had similar rates of pregnancy and live births.

“The finding that the live birth rate in the two groups was comparable suggests that transferring multiple embryos isn’t actually helping achieve the desired outcome,” Eaton said. “It’s basically just increasing the chance of multiple births, and that raises the risk of dangerous complications.”

Among IVF pregnancies resulting in a live birth, the study found a 29-percent multiple birth rate in mandated states versus 33 percent in non-mandated states.

After stratifying the data by mother’s age and the timing of embryo transfer, the study team learned that the association between state mandate status and multiple birth rate remained statistically significant only among patients younger than 35 who had embryo transfer on day five, when embryo implantation rates are highest. In these patients:

• 21.8 percent opted for single embryo transfer in mandated states versus 13 percent in non-mandated states;

• The rate of multiple birth was 33.1 percent in mandated states versus 38.6 percent in non-mandated states.

“This study definitively showed that, even after controlling for various differences between patients, elective single embryo transfer is more commonly performed and the multiple birth rate is lower in states that mandate IVF coverage, especially among younger women,” Eaton said of the findings.

Eaton pointed out that the majority of women under age 35 were still having more than one embryo transferred, even in states with coverage for IVF and in spite of SART recommendations that they pursue single embryo transfer while in this age group. 

“That means that although insurance mandates are likely an important method of improving the feasibility of single embryo transfer, they are probably not enough to solve the problem,” she said. “Ultimately, single embryo transfer is going to have to become more widely-adopted to solve the multiple birth crisis in the United States.”

The authors note the study may have been limited by input errors and elective reporting of data to SART. Additionally, the study did not compare how frequently IVF was used in each state and how that might have affected the absolute numbers of multiple births.

Finally, SART data do not account for whether patients have insurance. For example, it is possible that some patients in non-mandated states had insurance coverage for IVF.  Similarly, it is possible that some patients in mandated states did not actually have insurance coverage due to exceptions in the mandates. Eaton said these limitations should have biased the study towards showing no difference between the multiple birth rate among younger women in mandated and non-mandated states. However, since the researchers did find a statistically significant difference, Eaton said the idea of a possible link between state mandate status and the multiple birth rate is further strengthened.    

Eaton was joined by co-authors Meredith Provost, Samantha Thomas, Jason Yeh, and William Hurd, all from Duke.

The authors report no conflicts of interest. 

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