Multiple births -- twins, triplets or more babies in one pregnancy -- have more risks of infant death and long-term disabilities such as cerebral palsy than births of single babies do. However, many couples seeking infertility treatments desire multiples and have poor knowledge particularly about the risks for twins, a University of Iowa study reported.
The investigation found that one in five women seeking treatment desired multiples over having a singleton, or one baby. While patients usually knew about risks of triplets and higher order multiples, slightly less than 50 percent knew about twins' increased risk of cerebral palsy. Even fewer, 30 percent, knew of the increased risk of infant death, which is eight times higher for twins than for singletons. The findings appeared in the March 2004 issue of the journal Fertility and Sterility. The report also was accompanied by an editorial.
"Most of the twins seen in public or on the news are success stories. However, there are many risky and unsuccessful twin pregnancies," said Ginny Ryan, M.D., UI fellow in obstetrics and gynecology and study co-author. "It's important for infertile couples to be aware that twins are riskier, and from a program standpoint the focus should be on having one healthy child and not just on pregnancy rates."
The investigation by researchers from the UI Roy J. and Lucille A. Carver College of Medicine used a 41-question survey to evaluate women's demographics, infertility history, outcome desires, knowledge of risks, and goals of infertility evaluation and treatment. A total of 449 female patients seeking advice or treatment at one of three clinics responded to the questionnaire. Two sites were at UI Hospitals and Clinics and one was at a private gynecological practice in Cedar Rapids, Iowa.
Not having any children, being younger and having a lower income were factors associated with the increased desire to have twins or more babies.
The major problem with twin pregnancies is prematurity, where gestation typically is 36 weeks compared to 40 weeks for a singleton. Most women in the study, 95 percent, were aware of the risk of preterm delivery.
"The underlying interest for the study was that the number of multiple births has rapidly expanded. Although some of this is driven by physician practice, some of the increase is due to patient preference. We wanted to better understand that desire," said study co-author Brad Van Voorhis, M.D., the F.K. "Ted" Chapler Professor of Reproductive Endocrinology in the UI Carver College of Medicine, and Director, Division of Reproductive Endocrinology & Infertility at UI Hospitals and Clinics.
Because twins often do fine, and infertile couples who are trying to have babies often want to build their families quickly, the couples view twins as a "bonus." In addition, some insurance companies are willing to pay only for a limited number of treatments, raising the stakes for successful outcomes.
"Interestingly, lower family income played a role in increased desire for twins, which may indicate that some couples feared they might not be able to afford further treatment and wanted to build their families quickly with multiples," Van Voorhis said. "However, from a health care standpoint, we think it's important to educate couples about risks so they can truly make good decisions."
Van Voorhis added that some insurance companies seek to limit or even eliminate infertility treatment as a benefit because of the high complication rate for multiples. Other studies have found that lifetime costs to the health care system and society can be 100 to 200 times higher for each infant in a twin or triplet birth than for a singleton baby.
Ryan said next steps for the researchers include finding better ways to educate people who seek infertility treatments services, perhaps through written materials and counseling.
The clinics may also consider implementing a standard procedure to transfer only one good quality embryo per couple who meet certain criteria undergoing in vitro fertilization, which involves the transfer of fertilized eggs into a woman's uterus. Ryan noted that in Europe, where there is more governmental control, it is more common to transfer only one embryo.
Most infertility treatments involve the use of drugs that stimulate the ovaries to produce multiple eggs. When the stimulation is followed by insemination, a woman may become pregnant with several fertilized eggs. Some women choose to reduce this number. In another treatment approach, the stimulation is followed instead by in vitro fertilization (IVF). In IVF, the eggs are retrieved from the ovaries, fertilized and a decision is made regarding how many to put back.
A recent separate study on in vitro fertilization published in the New England Journal of Medicine (NEJM) by Brigham and Women's Hospital showed that doctors are implanting fewer embryos. As a result, there are fewer incidences of IVF triplets and higher order multiples. However, the rate of twins still is high among women using this technique.
"These NEJM findings are positive in identifying the trend to successfully reduce higher-order multiples, but decreasing the number of twins will be the next real hurdle," Ryan said.