Danish National In-Vitro Fertilization Registry 1994 and 1995: a controlled study of births, malformations and cytogenetic findings.

This paper reports data from the Danish in-vitro fertilization (IVF) registry from 1994 to 1995 including data on treatments and the results of these (perinatal outcome, cytogenetic findings and fetal malformations) in comparison with a control group matched for maternal age, parity, multiplicity and year of birth. There were 1756 deliveries of 2245 children (24.3% twins, 1.8% triplets). The rate of prematurity among IVF children was 23.8% (NS) [singletons 7. 3% (P < 0.05), twins 41.2% and triplets 93.5%], 23.6% weighed <2500 g [singletons 7% (P < 0.05), twins 42.2% and triplets 87.1%]. The perinatal mortality rate was 21.8 in the study group compared to 17. 4 in the control group (NS). In total, 13.2% of all clinical pregnancies and 15.4% of the pregnancies that resulted in a delivery had a prenatal genetic examination. Of all examined, 3.5% had an abnormal karyotype. In total, 107 (4.8%) children in the study group and 103 (4.6%) in the control group were born with malformations (NS), compared to 2.8% in the background population. Our results indicate that it is the characteristics of the patients and multiplicity of pregnancy, rather than the assisted reproductive technology that determines the fetal risks of IVF pregnancies compared to the background population.