Women who give birth after fertility treatment are more likely to have a stroke than those who conceived naturally, a study suggests.
Researchers at Rutgers University in New Jersey, who tracked 30 million pregnancies, found that women who conceived using fertility treatments such as in vitro fertilization (IVF) or intrauterine insemination (IUI), among others, had a 66 percent percent more likely to have a stroke within the next year. Giving birth.
They were twice as likely to have the deadliest form of stroke, a hemorrhagic stroke, when there is bleeding in the brain, and 55 percent more likely to have an ischemic stroke, caused by a blood clot than cuts off the blood supply to part of the brain. brain.
Stroke is the leading cause of death among pregnant women and is said to be due to the strain pregnancy places on the body. Approximately 30 out of 100,000 women who give birth suffer a stroke up to a year after delivery.
It was not immediately clear why women who received fertility treatments were at higher risk, but the researchers said it could be due to the hormone treatments women undergoing the procedures must take, as well as an increased risk for these women. women that the placenta does not implant. properly.
Researchers at Rutgers University in New Jersey, who tracked 30 million pregnancies, including nearly 300,000 with IVF, found that those who used IVF were 66 percent more likely to be hospitalized with a stroke one year after delivery ( stock)
This graph shows the increased risk of stroke among 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 families. A record number of women in their 40s are now giving birth, official data shows, as the US birth rate continues to decline.
IVF is one of several fertility treatments available to conceive a baby. During the process, an egg is removed from the ovaries and fertilized with sperm in a laboratory. This embryo is then implanted in the woman’s uterus to grow and develop.
IUI is a process that involves injecting sperm directly into the uterus.
While receiving treatments, patients are injected with the hormone estrogen to stimulate the release of an egg (ovulation) and the growth and maintenance of the uterine lining.
Higher levels of estrogen, which can be well above natural levels, can cause damage to the lining of blood vessels and increase the amount of clotting factors in the blood, increasing the risk of stroke .
In addition to suffering a stroke, women undergoing IVF are also at increased risk of ischemic disease of the placenta, when the placenta is too small or does not adhere properly to the lining of the uterus.
The scientists said this could increase the risk of stroke by triggering high blood pressure as the body tries to get more blood and nutrients to the uterus, higher levels of inflammation due to stress, and an increase in the amount of clotting factors in the womb. blood to prevent severe bleeding.
The scientists also suggested that women receiving fertility treatments may have more underlying health risks, such as obesity, smoking or alcohol use, all of which can make it difficult to conceive naturally.
It was also suggested that age was a factor. Although the average age of the women who used IVF in the study was 32 years (below the threshold of 35 where the risk increases), it was older than that of those who “conceived spontaneously” in the study, which was 27. years.
The scientists said that strokes did not occur 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 open JAMA networkthe scientists looked at 30 million pregnant women in the National Readmission Database, which stores data on patients and whether they were readmitted to hospitals in 28 US states.
They reviewed the records of 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 in order to conceive.
The data showed that there was a hospitalization rate of 37 readmissions per 100,000 women in 12 months for those who underwent fertility treatments.
But for those who became pregnant naturally, this rate dropped to 29 per 100,000.
An analysis was then carried out, adjusting for factors such as maternal age, multiple births, type of hospital and income, which showed a 66 percent increased risk for women who had received fertility treatment.
Among the women who underwent treatment, 52 (18 per 100,000) were hospitalized for a hemorrhagic stroke.
But among those who became pregnant naturally, 3,791 (12 per 100,000) were hospitalized for hemorrhagic stroke.
Details about how many children each woman gave birth to and whether those who received fertility treatments were in their first pregnancy or consecutive pregnancies were not documented.