A study shows that women who give birth after fertility treatment are more likely to have a stroke than women who conceived naturally.
Researchers at Rutgers University in New Jersey, who tracked 30 million pregnancies, found that women who got pregnant using fertility treatments such as in vitro fertilization (IVF) or intrauterine insemination (IUI) were 66 percent more likely to conceive within a year. having a stroke after pregnancy. birth.
They were twice as likely to have the more deadly form of stroke, a hemorrhagic stroke, which involves bleeding in the brain, and 55 percent more likely to have an ischemic stroke, which is caused by a blood clot blocking blood flow to part of the brain. brain cut off. the brain.
Stroke is the number one cause of death among pregnant women, and is caused by the stress pregnancy puts on the body. About 30 in 100,000 women who give birth will have a stroke up to a year after giving birth.
It wasn’t immediately clear why women undergoing fertility treatments were at higher risk, but the researchers said this could be due to the hormone treatments women undergoing the procedures have to undergo, and a higher risk for these women of the placenta failing to implant. . the right way.
Researchers at Rutgers University in New Jersey, who tracked 30 million pregnancies — including nearly 300,000 that involved IVF — found that those who used IVF were 66 percent more likely to be hospitalized with a stroke a year after giving birth. recorded (inventory)
This graph shows the increased risk of stroke in women receiving IVF
The number of women becoming pregnant through IVF or IUI continues to rise as more Americans wait until later in life to start a family. A record number of women in their 40s are now giving birth, official data shows, as the US birth rate continues to fall.
IVF is one of the many fertility treatments available to conceive a baby. In the process, an egg cell is removed from the ovaries and fertilized with sperm in a laboratory. This embryo is then implanted into the woman’s uterus to grow and develop.
IUI is a process of injecting sperm directly into the uterus.
While undergoing treatments, patients are injected with the hormone estrogen to stimulate the release of an egg (ovulation) and the growth and maintenance of the endometrium.
The higher levels of estrogen — which can be well above natural levels — can cause damage to the lining of the arteries and increase the number of clotting factors in the blood, increasing the risk of stroke.
In addition to stroke, women undergoing IVF also have a higher risk of ischemic placental disease – when the placenta is too small or does not attach properly to the uterine lining.
The scientists said this could increase stroke risk by causing high blood pressure as the body tries to get more blood and nutrients to the uterus, higher levels of inflammation due to stress and a rise in the number of clotting factors in the blood. avoid severe bleeding.
Scientists also suggested that women undergoing fertility treatment may have more underlying health risks, such as obesity, smoking or alcohol consumption, all of which can make it more difficult to conceive naturally.
It was also suggested that age would be a factor. While the average age of women using IVF in the study was 32 years old – below the 35 year threshold where the risk increases – it was older than those who ‘got pregnant spontaneously’ in the study, at 27 years old.
Scientists said the strokes didn’t happen until after pregnancy because they were caused by a drop in blood pressure as the body returned to its pre-pregnancy state.
In the study, published Wednesday in JAMA network openedscientists looked at 30 million pregnant women in the Nationwide Readmissions Database, which stores data about patients and whether they have been readmitted to hospitals in 28 states in the US.
They reviewed data from more than 31 million women who gave birth between 2010 and 2018.
Of the pregnant women in the study, 287,000 — less than one percent — had undergone fertility treatment to conceive.
Data showed that within 12 months there was a hospital readmission rate of 37 readmissions per 100,000 women for those undergoing fertility treatments.
But for those who got pregnant naturally, the rate dropped to 29 per 100,000.
An analysis was then performed – adjusting for factors such as maternal age, multiple births, hospital type and income – which found that women who had undergone fertility treatment had a 66 percent higher risk.
Of the women who underwent treatment, 52 – 18 per 100,000 – were hospitalized for a brain haemorrhage.
But of those who became pregnant naturally, 3,791 – 12 in 100,000 – were hospitalized for a brain haemorrhage.
Details of how many children each woman gave birth to and whether those who received fertility treatments during their first or subsequent pregnancies were not documented.