It is reported that pre-existing heart disease in pregnancy remains a concern as complications are frequent and in some cases may be life-threatening for both the mother and her child.
In Europe maternal heart disease has now become the major cause of maternal death during pregnancy.
As interim data from the ESC's special registry on pregnancy in cardiac disease suggests, the numbers of women at risk is not in decline, mainly because of today's older age at first pregnancy and with it a concomitant increase in risks of diabetes, hypertension and obesity.
Professor Jolien Roos-Hesselink, joint chairman of the ESC registry together with Professor Roger Hall (Norwich, UK), reported that the most frequently diagnosed condition in the registry population was congenital heart disease, found in around 60% of subjects. More than 1300 women have been enrolled into the registry so far - from 28 countries and 60 centres; they consist of 869 women with congenital heart disease, 333 with valvular heart disease patients, 79 with cardiomyopathy and 24 with ischaemic heart disease.
Professor Roos-Hesselink said that evidence in this field is sparse, with randomised trials impossible to perform: "So the only way to improve our knowledge of the factors which determine outcome in pregnant women with heart disease is to gather data on a large number of pregnancies and try to find patterns of outcome which correlate with management strategies. In this way we might determine the areas of danger for both mother and child and the best forms of treatment." It was because of the need to generate relevant data in areas such as this, that the concept of European registries was developed in 2006. Data collection in the pregnancy and CVD registry began in 2008, with information recorded on CVD diagnosis, medication, cardiac complications, obstetric complications, and pregnancy outcome at six months.
An interim analysis of these pregnancies was presented at the ESC Congress but, said Professor Roos-Hesselink, data collection continues and it is clear larger numbers will be required to obtain meaningful conclusions.
However, results so far reflect a very high hospitalisation rate during pregnancy: 338 patients (26% of all pregnancies) were hospitalised, 203 of cardiac cause. Maternal death occurred in 13 patients (1%) and fetal death in 59 cases (4.5%). These death rates, said Professor Roos-Hesselink, are significantly higher than normal; maternal mortality is in the order of 100 times higher and fetal mortality 10 times higher. There was also a high rate of delivery by Caesarean section of around 40%.
She added that no single cause for the high mortality rate is as yet clear, but the further analysis and larger numbers of the study should provide stringer evidence. "We are analysing patterns of therapy as well trying to identify the particular underlying cardiac conditions associated with mortality," she said.