A quality control study was made of the Swedish Medical Birth Registry. This registry used one mode of data collection during 1973-1981 and another from 1982 onwards. The number of errors in the register was checked by comparing register information with a sample of the original medical records, and the variability in the use of diagnoses between hospitals was studied. Different types of errors were identified and quantified and the efficiency of the two methods of data collection evaluated.

Women using antidepressants during pregnancy and their newborns have increased pathology. It is not clear how much of this is due to drug use or underlying pathology. Use of TCAs was found to carry a higher risk than other antidepressants and paroxetine seems to be associated with a specific teratogenic property.

We studied a large data set from three registries of congenital malformations (central- (JMed Genet 1996;33:809-813)

The effect of various antipsychotics during pregnancy has repeatedly been studied, but for most atypical antipsychotics, only little information is available. We identified from the Swedish Medical Birth Register 2908 women who had reported the use of any antipsychotic or lithium in early pregnancy and studied malformation rates with data also from the Register of Congenital Malformations and the Hospital Discharge Register. Comparisons were made with all births (n = 958,729) after adjustment for some confounders. Risks were expressed as odds ratios (ORs). Most women had used dixyrazine or prochlorperazine mainly because of nausea and vomiting in early pregnancy. Seventy-nine women had used lithium, and these outcomes are reported separately. Hence, the main analysis was restricted to 570 women (576 infants) using other antipsychotics. There was a statistically significant increase in the risk for a congenital malformation-after exclusion of some common and minor conditions, the OR was 1.52 (95% confidence interval, 1.05-2.19). Exclusion of infants exposed to anticonvulsants reduced the OR only slightly. Most of the increased risk was caused by cardiovascular defects, mainly atrium or ventricular septum defect. No certain drug specificity was found. Except for an increased risk for congenital malformations, a nearly doubling of the risk for gestational diabetes and a 40% increased risk for cesarean delivery was noted. Because there seems to be little drug specificity, it is possible that underlying pathology or unidentified confounding explains the excess risk.

The presence of congenital malformations in infants born after IVF was studied from a register consisting of practically all infants born in Sweden after IVF, 1982--1997 (n = 9111). A further 64 infants were studied using only medical records. It is a nation-wide study and has a population-based control group (n = 1,690,577) and relevant potential confounders have been taken into account. There was an excess of congenital malformations registered in the Medical Birth Registry (n = 516, odds ratio = 1.47) but this excess disappeared when confounders were taken into consideration: year of birth, maternal age, parity, and period of unwanted childlessness (odds ratio = 0.89). For some specific conditions, an approximately 3-fold excess risk was seen: neural tube defects, alimentary atresia, omphalocele, and hypospadias (after intracytoplasmatic sperm injection). No excess risk for hypospadias was seen after standard IVF. Various explanations for these findings are discussed. It is postulated that the excess risk for alimentary atresia, like the excess risk for monozygotic twinning after IVF, is a direct consequence of the IVF procedure. The excess risk for hypospadias after ICSI may be related to paternal subfertility with a genetic background. The absolute risk for a congenital malformation in association with IVF is small.