Scientists monitored more than one million women who had taken fertility drugs in the two years before giving birth. The women were followed for around ten years to see if they developed forms of heart disease such as heart attacks, strokes, blood clots and heart failure.
Women who had received fertility treatment were not more likely to develop higher rates of heart disease compared to those who had received no such treatment, the study found, despite the fertility patients having more risk factors due to being five years older on average. In fact, women who used fertility treatments had slightly lower levels of heart disease, but the researchers put this down to these women adopting healthier lifestyles to increase their chances of pregnancy. The study did not involve any women who had fertility treatment but did not give birth to a child.
'The speculated association between fertility therapy and subsequent cardiovascular disease is not surprising given that more women are waiting until an older age to have children, when they are at greater risk of developing heart disease', said Dr Jacob Udell, lead author of the study and cardiologist at Women's College Hospital, Canada.
Fertility drugs can be taken in the form of injections which stimulate egg production. They are known to increase the risk of high blood pressure and gestational diabetes during pregnancy, and so researchers wanted to find out if there was also a link between fertility drugs and the risk of heart disease in women following the birth of their children.
Dr Donald Redelmeier, study co-author, from the Institute for Clinical Evaluative Sciences (ICES), said: 'Overall, the single most important finding is that women who deliver following fertility therapy had fewer of these cardiovascular events than controls.'
'Our findings are encouraging but further research is necessary to explain the full impact of fertility therapy on women's health', said Dr Udell. 'With a better understanding of the long-term health effects associated with fertility therapy, we can help inform decision making and reduce potential health risks to women.'
The results were published in the Journal of the American College of Cardiology.