0145 GMT December 06, 2019
The research, found that women who suffered from severe asthma during their pregnancy were around 30 percent more likely to suffer from the condition which can result in the death of the mother or child, telegraph.co.uk reported.
Scientists also found that severe asthma attacks also had an impact on the health of the child, with babies 14 percent more likely to be born prematurely and 21 percent more likely to have a birth abnormalities
Researchers compared pregnant women with well-controlled asthma with those who had experienced severe symptoms.
They noted that the findings are important because a large number of women with asthma are known to decrease or stop taking asthma medication during pregnancy.
Lead researcher, Dr. Kawsari Abdullah, a research fellow at the Children's Hospital of Eastern Ontario in Canada, said: "Asthma is the most common chronic disease in pregnant women, affecting eight to 13 of pregnant women worldwide.
"If asthma is poorly controlled, patients can suffer with severe symptoms such as wheezing, coughing, or feeling breathless or tight-chested.
“Previous research has shown that one out of every three pregnant women with asthma will suffer severe symptoms, so we need to understand what this means for women and their babies."
There were 14,352 pregnancies in 2017/18 with pre-eclampsia with 39 women in England diagnosed with the condition every day which can lead to fits that can be life threatening for the mother and child.
The study, the largest of its kind conducted to date, included data on more than 100,000 pregnancies and found that asthma was also more likely to be passed on to the child if the mother had a severe outbreak of the condition.
Of the children born between 2003 and 2012, their risk of asthma up to the age of five years was 23 percent higher, with their risk of pneumonia also rising by 12 percent.
Dr. Teresa To, the senior researcher on the study, said: "This is the biggest study looking at the risks associated with severe asthma symptoms in pregnancy and it's also the first to show the longer-term impacts on children up to the age of five years.
“Our results reinforce the findings of smaller studies that uncontrolled asthma can be bad for mothers and their babies.
"Nearly 40 percent of pregnant women decrease or stop taking asthma medication because they are worried that it could be harmful to their unborn babies. However, our study indicates that severe asthma symptoms present the greater risk to mother and baby.
"This study does not explain why asthma attacks contribute to all these health issues, but the likely mechanism is reduced oxygen supply for the mother and subsequently to the baby in the womb."