New contraceptives create a need for knowledge about the risks of long-term use

In recent years, more and more women have discarded the classic contraceptive pill and switched to newer types of hormone products as contraception. Examples are low-dose hormonal IUDs or products containing progestin, which is an artificially produced hormone.

The many new products raise new questions, because what happens to the body if you use them for more than 15 years of your life?

»From the classic contraceptive pills being the dominant choice, it is now the progestin-containing products that are the most dominant. We don't know much about them or the combined pills with newer progestins, because historically they have been used much less ,« says Lina Steinrud Mørch, Team Leader at the Danish Cancer Society.

She will lead a research project in close collaboration with an interdisciplinary research team that, with support from Independent Research Fund Denmark, will investigate how the new products on the market affect the body. Some of them are also used for severe menstrual pain and diseases such as endometriosis.

»We want to be able to assess the risk for the individual woman. So, if a woman is of a certain age and has a certain health history, then what is her absolute risk of different side-effects when using a product? The absolute numbers are missing out there today,« explains Lina Steinrud Mørch.

Based on data from two million Danish and Swedish women

The research is divided into three parts, the first and largest of which is about the latest contraceptive products and how to use them wisely to minimise your risk.

Here, the researchers will make use of data from health registries in Denmark and Sweden. This makes it possible to follow more than two million women over time and quantify the absolute risk of known side effects, such as cancer and blood clots.

Another part looks at how effective the low-dose products are when used as treatment. For instance, against severe menstrual pain or endometriosis.

»For example, high-dose hormonal IUDs are approved to treat endometriosis, but these completely new products are not,« Lina Steinrud Mørch elaborates.

To gain the necessary insight, the Danish Cancer Institute has already through another collaborative project collected answers about these disorders and contraception from more than 200,000 women using a questionnaire.

The third part of the research is about what mothers' use of contraception means for the children's health.

The research is scheduled to run for three years and will take place as a collaboration between the Danish Cancer Institute, Nordsjællands Hospital – Hillerød, Steno Diabetes Centre and the Karolinska Institute in Sweden.

Progress will be announced regularly

For the individual woman, it will normally be her general practitioner who will provide advice and guidance on contraception. It is, of course, an advantage if the doctor has access to the latest knowledge in the field.

Therefore, the researchers will continuously report on the knowledge gained during the project.

»Our research has a real impact when, for example, the gynaecological societies or the Danish Health Authority develop guidelines. We hope that the knowledge we provide will help close knowledge gaps and enhance nuance to these guidelines. So, it is clear that we intend to engage in a dialogue with the Danish Health Authority and send the authority our findings as they become available, so that they can support the guideline development process,« says Lina Steinrud Mørch.