High blood pressure in pregnancy linked to thyroid problems later

Link:http://www.guardian.co.uk/lifeandstyle/besttreatments/2009/nov/18/high-blood-pressure-in-pregnancy-linked-to-thyroid-problems-later
BMJ Group
Women who get high blood pressure in pregnancy (a condition called pre-eclampsia) may be at risk of having an underactive thyroid gland in later life, according to new research.

What do we know already?

Pre-eclampsia is an illness that happens only in pregnancy. As well as causing problems for the baby, it leads to the mother having high blood pressure and puts her at risk of having seizures or kidney damage. In severe cases, doctors have to deliver the baby early, to protect the health of both mother and baby.

Some studies suggest that women with pre-eclampsia also have low levels of hormones produced by the thyroid gland, which is in the neck. These hormones regulate how your body uses energy from food. If the thyroid gland doesn't produce enough of these hormones, this is called an underactive thyroid, or hypothyroidism. Many women with mild hypothyroidism have no symptoms, but others may feel tired, put on weight, and get depressed. Without treatment, symptoms may get worse. It's possible this condition may also increase chances of heart disease.

Although blood pressure usually goes back to normal after women with pre-eclampsia have their babies, studies have shown some long-term risks. Women who've had pre-eclampsia are more likely to have heart disease later in life. Doctors think that an underactive thyroid gland may increase this risk.

What does the new study say?

The study was in two parts. The first part found that 24 percent of women with pre-eclampsia had levels of hormones in their blood that suggested they had an underactive thyroid gland. This compared to 14 percent of pregnant women without pre-eclampsia. The blood samples were taken shortly before the women gave birth.

The second part of the study looked at long-term medical information about a large group of women. It found that women who'd had pre-eclampsia during their first pregnancy were more likely to have levels of hormones indicating an underactive thyroid gland as long as 20 years later. The link was even stronger for women who'd had pre-eclampsia in two pregnancies.

How reliable are the findings?

All the research was done on stored blood samples from a large group of women who'd taken part in the studies. So the results should be pretty reliable.

Where does the study come from?

The research was done by researchers from universities in the US, and it also used data from a long-term study carried out in Norway. The study was published in the BMJ (British Medical Journal).

What does this mean for me?

If you've had pre-eclampsia in pregnancy, you may have an increased chance of getting an underactive thyroid gland in future. Bear in mind that having an increased chance isn't the same as saying you will definitely get thyroid problems. But if you find you have symptoms such as gaining weight without reason and feeling very tired, it's worth asking your doctor to check your thyroid function. An underactive thyroid gland can be successfully treated with hormone tablets.