Chronic Hypertension and Acetyl Salicylic Acid in Pregnancy

This study is about pregnant women who have long-term high blood pressure, also known as chronic hypertension. About 1 to 5 out of every 100 women have this condition. For those who do, there's a higher chance of developing serious problems during pregnancy. These can include pre-eclampsia (a serious condition with high blood pressure and organ damage), the baby not growing as well as expected, or other severe health issues for both mother and baby. If these problems become severe, sometimes the only option is to deliver the baby early, which can carry its own risks. Because there's no cure once these problems start, finding a way to prevent them is really important for the health of mothers and their babies.

Some health experts in the UK and USA already suggest that women with chronic high blood pressure take a low dose of aspirin during pregnancy to help prevent pre-eclampsia. However, this recommendation is based on studies in other groups of women, and there isn't a lot of specific research showing how well it works for women with long-term high blood pressure. Some research in the past used very low doses of aspirin or started it later in pregnancy, and the results weren't always clear. Because of this, some other health bodies, like those in France, haven't yet made the same recommendation, waiting for more solid information.

This study aims to get clear answers. It will compare a daily dose of 150mg aspirin with a dummy pill (placebo) to see if aspirin, started before 20 weeks of pregnancy, can effectively reduce the risk of these complications for mothers and babies. By doing this, the researchers hope to provide strong evidence to help guide future care for pregnant women with chronic high blood pressure.