FRIDAY, Jan. 23, 2004 (HealthDayNews) -- Nearly 26 years after the first in-vitro fertilization baby, a new study finds a much higher risk of birthing problems among newborns whose conception was medically assisted.
The study found the problem to be "significantly worse" for single births, but less so for twins. Compared to naturally conceived babies, singleton babies born following medically assisted conception are three times likelier to have a low birth weight, 3.27 times likelier to be born very premature, and 1.68 times likelier to die during delivery, Dutch researchers say.
Assisted-conception singleton babies also faced an increased risk of stillbirth, being delivered by Caesarean section, and being admitted to a neonatal intensive care unit.
The problems don't end at birth, the study found: Extremely premature and low birth-weight babies tend have a higher chance of developing complications later in life.
The research, a review of 25 other studies, appears in the Jan. 24 issue of the British Medical Journal. Another expert cautioned, though, that while the relative risk was higher, the absolute risk was small.
"Now we know that there is really an assisted reproduction problem which affects birth weight and the duration of pregnancy," says study author Dr. Frans M. Helmerhorst, an expert in reproductive medicine at Leiden University Medical Center in The Netherlands. "Thus there is now a clear message to the researchers: Try to identify the problem."
But the report found the risks for assisted twin births were not as high as with naturally conceived twins, and even showed less risk at in some problem areas -- most notably, a 40 percent lower risk of dying during childbirth.
The review found that twins conceived with medical assistance also had a 5 percent higher rate of intensive care admissions, a 21 percent higher rate of premature and Caesarian delivery rates, and a 27 percent increased risk of being small for gestational age. The differences, however, were far less marked than between groups of single births.
Another expert says that a lot of factors are at work, and the problem has to be kept in proportion.
"It's not something the public should focus on," says Olga Basso, a professor at the University of Aarhus Epidemiology Science Center in Denmark. "One thing that has to be kept in mind is that in developed countries like ours with good neonatal care, the background risk -- even a doubling of that risk -- doesn't imply a high number." It "still is actually quite a small number," she says.
"Is it the treatment itself that could be the problem, or the background issues as to why she couldn't conceive in the first place?" Basso adds.
"Morbidity and mortality in those children are predominantly associated with very preterm singletons and very low birth weight -- a small group," Helmerhorst says.
"So far, reproductive medicine has concentrated on conception, but the focus should now shift to achieving a successful birth," the study states. "Women undergoing assisted reproduction programs should also be made properly aware of these risks. And more work should be done on reducing risks for babies conceived with medical help."
Thomas D'Hooghe, director of the fertility clinic at Belgium's Catholic University at Leuven, says the study is one of the first summarizing all the evidence currently available.
He offers several suggestions for reducing the risks. They include investigating for infertility early (after a year and a half of problems conceiving); treating possible causes by surgery, hormones or intrauterine insemination; and, if those therapies fail, resort to assisted reproduction as a last resort. He also says more women should consider conceiving before they turn 30.
"The end point should indeed be the delivery of a healthy child," D'Hooghe adds.
More information
Read more about infertility and assisted reproduction at the National Infertilty Association or the Centers for Disease Control and Prevention.
