The prevalence of major congenital malformations during two periods of time, 1986-1994 and 1995-2002 in newborns conceived by assisted reproduction technology.

Evidence has emerged that assisted reproduction technology (ART) may be associated with an increased risk of congenital malformations, low birth weight, and genetic imprinting disorders. The aim of the study was to determine, the prevalence of major malformations in newborns conceived by standard in vitro fertilization (IVF) in 1986-1994 and newborns conceived by different types of ART procedures in 1995-2002. Data were collected from the IVF Registry and Israel Birth Defects Monitoring System for all infants (live births, stillbirths and terminations of pregnancy) delivered after 20 weeks' gestation who achieved a fetal weight of at least 500 g. The control groups consisted of all spontaneously conceived babies (live births, stillbirths and terminations of pregnancy) born in our center during the same time periods. During the first period, a total of 31,007 babies were born at our center, of whom 278 were conceived by standard IVF. Twenty-six of the IVF infants had major malformations, for a prevalence rate of 9.35%, which was 2.3-fold higher than that in the general population (4.05%). During the second period, 53,208 infants were born, of whom 1632 were conceived by ART. Major malformations were found in 147 ART infants, for a prevalence rate of 9.0%, which was 1.75-fold higher than in the general population (5.18%). Analysis of the clinical characteristics of the ART infants with major malformations showed that 70.3% were born preterm, 76.5% had low birth weight, 58.6 were twins, and 11.7% were triplets. The use of ART procedures increased by a factor of 3.4 in the second period. Two important outcomes of ART were observed: an increased prevalence of major malformations about double the general population in both periods, and a high frequency of adverse clinical characteristics among ART infants with major malformations. Infertile couples should be adequately counseled regarding the real risk of having a child with malformations or a preterm or low birth weight infant.