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

Abstract

5To whom correspondence should be addressed This paper reports data from the Danish in-vitro fertiliza- tion (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) (single- tons 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 deter- mines the fetal risks of IVF pregnancies compared to the background population.