In vitro fertilisation (IVF) may increase the risk of birth defects, said researchers at the ongoing American Academy of Pediatrics (AAP) National Conference.

Researchers found 3,463 infants with major birth defects were identified among 4,795 infants born after IVF and 46,025 naturally conceived infants with similar maternal demographics.

Birth defects for infants born after IVF were nine percent compared to 6.6 percent for naturally conceived infants even after controlling for maternal factors, China's Xinhua news agency reported.

Malformations of the eye (0.3 percent versus 0.2 percent), heart (five percent versus three percent), and genitourinary system (1.5 percent versus one percent) were greater in IVF infants.

Overall, an IVF infant's odds of birth defects were 1.25 times greater than that of a naturally conceived infant with similar maternal characteristics. Risk of birth defects after other fertility treatments such as artificial
insemination or ovulation induction alone were not significant.

"Our findings included a significant association between the use of assisted reproductive technology, such as certain types of in vitro fertilization and an increased risk of birth defects," said study author Lorraine Kelley-Quon, a general surgery resident at Ronald Reagan University of California, Los Angeles
Medical Centre.

The AAP national conference is held from Oct 20 to 23 in New Orleans.