Their results, published in the June issue of the Journal of Child Psychology and Psychiatry, suggest that it's more difficult for youngsters to deal with the idea that they grew in an unrelated woman's womb, than with the concept that they are not biologically related to one or both parents.
With the number of births involving a surrogate or donated sperm or eggs on the rise, this issue may become increasingly relevant.
The latest statistics from the American Society for Reproductive Medicine (ASRM) show that the number of children who were created with a donated egg rose more than 30 percent from 7,284 in 2004 to 9,541 in 2011, while the number of births involving a surrogate jumped more than 200 percent, from 530 in 2004 to 1,179 in 2011. No one knows how many births have resulted from sperm donations, but estimates range from 30,000 to 60,000 per year, according to a New York Times report.
For the study, [family research professor Susan] Golombok and her colleagues followed 30 surrogacy families, 31 egg donation families, 35 sperm donation families and 53 natural conception families until the children were 10 years old. The researchers surveyed the moms when the children were ages 3, 7 and 10 to get an idea of how well-adjusted the youngsters were.
"Signs of adjustment problems could be behavior problems, such as aggressive or antisocial behavior, or emotional problems, such as anxiety or depression," Golombok says.
There was no difference between children born through egg and sperm donation or children conceived naturally in terms of behavioral adjustment, the researchers found.
While all the children seemed to be doing well by age 10, Golombok says, the concern is, trouble could crop up later as kids hit their adolescence and are trying to find their identities and place in the world, experts say.
The most important thing, experts agree, is for parents to find a way to tell their kids about their beginnings.
Golombok and her team hopes to revisit the subjects when they are 14 years old, to see how these emotional issues play out in adolescence.
Image: Mother and daughter, via Shutterstock