The Swedish Medical Birth Register

Why is the stillbirth rate in Sweden the same today as it was 20 years ago, while the rate of early neonatal deaths continues to decrease? The Swedish Medical Birth Register (MBR) cannot answer this question but it is the source from which we can get the figures in the form of descriptive statistics. These data are of great interest and serve one of the purposes of the MBR, namely the surveillance of antenatal, obstetric and neonatal care. Information of this kind will also help researchers in perinatal medicine to ask the right questions and, in addition, the MBR can be used to identify cases, such as stillbirths, and controls and thus enable the performance of case/control studies. More information can then be retrieved from medical records. Thus the MBR is an important database for perinatal epidemiological research. Moreover, data from MBR can also be cross-linked with data from other registers at the Swedish National Board of Health and Welfare, which opens up exciting possibilities to perform studies in perinatal epidemiology. Viveca Odlind et al. (1) report in this issue that more than 300 scientific reports have emerged using data from the MBR. Concerning stillbirths, the MBR has made it possible to identify risk factors (2,3), which is the first and necessary step on the road towards management studies and changes in clinical practice with the aim of reducing the number of stillbirths. Today, the stillbirth rate is almost 4/1000 ongoing pregnancies, which means that in Sweden about 400 infants/year die in utero. The majority of these infants are non-malformed and have the potential for a long life if we could identify the risk pregnancies and develop methods for monitoring in order to intervene when necessary. The MBR could be an even better instrument if all fetuses dying in utero after 22 weeks were registered instead of the current 28 weeks. Such a change would make it easier to perform international comparisons and provide a better reflection of modern perinatology. However, even in its present form the MBR is an invaluable aid in finding the right track towards improved perinatal care and decreased perinatal morbidity and mortality. The MBR tells us that the rate of twin-pregnancies has increased substantially, especially during the past 15 years, and also that multiple pregnancies carry an increased risk for perinatal mortality and morbidity. Assisted reproduction, one of the risk factors for twin-pregnancies, can be influenced by the medical profession, and the MBR and other sources (4) demonstrate for us that the aim of assisted reproduction should be single pregnancies. The rate of cesarean sections has more than doubled since the introduction of the MBR. The reasons for this apparent change are not fully understood but increased consideration of fetal health factors, less fear of surgical and anesthesiological complications and nonacceptance of protracted deliveries are plausible contributory factors. Moreover, doctors of today are well trained to perform cesarean sections and less well trained to perform vaginal birth procedures, for instance extractions at breech deliveries. The fact that doctors use the procedures they are most confident with cannot be criticized. To date, there are no signs that the increase in cesarean section rate carries any substantial increased morbidity or mortality for the mother or the infant. There is, however, a potential for forthcoming maternal morbidity in the form of more placental complications such as placenta previa and accreta and also for more cases of uterine rupture. The MBR will be able to give us correct information about that in the future. A positive change recorded in the MBR is a substantial reduction in smoking during pregnancy. Smoking is a risk factor for many severe complications in pregnancy including fetal growth retardation, premature delivery and stillbirth. As smoking is a stronger risk factor among older women (5), it is satisfying to note that very few women over 30 smoke during pregnancy. Early discharge (within 48 h) after delivery was very uncommon in 1973 but today almost 50% of women leave the hospital soon after delivery. This profound change is, in contrast to many other changes, due to a deliberate shift in policy to enable women and newborns to be followed up at home. Apart from the few data I have commented on, the MBR contains a lot of statistics which is of interest in itself and is a foundation for creative thinking and for the formulation of hypotheses to be tested. Anders Ericson was the promoter of the MBR and supervised it through the years. He did not find a goldmine, he created one. He has given us an instrument of lasting value and enabled us to improve the health of mothers and newborns. Address for correspondence: Ove Axelsson Department of Women's and Children's Health, Obstetrics and Gynecology Akademiska Sjukhuset SE-751 85 Uppsala Sweden e-mail: ove:email protected