Asthma attacks in pregnancy tied to complications for mothers, babies

Asthma attacks during pregnancy are associated with an increased risk of complications for mothers and their babies, a Canadian study suggests.

Researchers examined data on more than 103,000 pregnancies among more than 58,000 women with asthma who had babies in Ontario, Canada, from 2003 to 2012.

Compared to women who didn’t have asthma attacks during pregnancy, those who did were 17% more likely to have pregnancy-induced hypertension and 30% more likely to have dangerously high blood pressure known as preeclampsia, the study found.

Women who had asthma attacks were also 14% more likely to have low-birthweight or preterm babies and 21% more likely to have infants with birth defects.

“Nearly 40% of pregnant women decrease or stop taking asthma medication because they are worried that it could be harmful to their unborn babies,” senior study author Teresa To of the Hospital for Sick Children in Toronto and the Children’s Hospital of Eastern Ontario Research Institute in Ottawa said in a statement.

“However, our study indicates that severe asthma symptoms present the greater risk to mother and baby,” To said.

While the study wasn’t designed to prove whether or how asthma attacks during pregnancy might cause complications for mothers or babies, it’s possible this happens because flare-ups reduce oxygen supplies for both women and their developing infants, To said.

Asthma is the most common chronic disease encountered in pregnancy, occurring in up to 13% of pregnancies, To and colleagues write in the European Respiratory Journal.

About one in three pregnant women with asthma have exacerbations during pregnancy, previous research has found. These exacerbations have been previously linked to complications like high blood pressure for mothers and early arrivals for babies, but much of the research to date has compared women with and without asthma, making it unclear how much uncontrolled asthma might play a role, the study team notes.

For the current study, researchers followed women through pregnancy then followed their babies for up to five years.

Asthma attacks during pregnancy were rare, even though all of the study participants had asthma. A total of 2,663 women had asthma attacks during a total of 4,455 pregnancies, the study found.

Pregnant women who had asthma attacks were more likely to be older, and more likely to smoke or to have limited income or insecure housing, the study found.

Preeclampsia developed in 5.3% of pregnancies among women who did have asthma attacks, and just 3.8% of pregnancies among other women in the study.

In addition, women developed pregnancy-induced hypertension in 7% of pregnancies involving asthma attacks, compared with 5.4% of other pregnancies.

Low birth weights occurred in 6.8% of pregnancies with asthma attacks, compared with 5.3% of other pregnancies, the study also found. Similarly, preterm births occurred in 8.2% of pregnancies involving asthma attacks compared with 6.7% of other pregnancies.

When women had asthma attacks during pregnancy, their children were also more likely to experience allergies and respiratory infections like pneumonia.

And, 6.2% of babies had birth defects in pregnancies involving asthma attacks, compared with 5% of infants born to mothers who didn’t have asthma attacks during pregnancy.

Children were also 23% more likely to develop asthma in early childhood when mothers had asthma attacks during pregnancy. These children were also 12% more likely to have pneumonia during their first five years of life.

Women were considered to have asthma attacks or severe asthma exacerbations if they visited a doctor at least five times for asthma problems during pregnancy or if they went to a hospital or emergency room for asthma symptoms.

One limitation of the study is that this definition might not always correctly identify women with uncontrolled symptoms, the study authors note. Some women with five or more checkups for asthma symptoms during pregnancy could in fact be controlling their illness well.

Even so, the results underscore the importance of careful asthma management during pregnancy, Professor Jorgen Vestbo, chair of the European Respiratory Society’s Advocacy Council and a researcher at the University of Manchester in the UK, said in a statement.

SOURCE: bit.ly/2P7lzhD European Respiratory Journal, online November 26, 2019.

Prenatal smoking tied to worse asthma in kids

NEW YORK- Children whose mothers smoked during pregnancy may have a tougher time controlling their asthma than other kids do, a new study suggests.

The findings, from a study of nearly 2,500 U.S. kids, add to evidence that prenatal smoking may affect children's future lung health.

There are already plenty of reasons for women to quit smoking during, and ideally before, pregnancy, said lead researcher Sam Oh, of the University of California San Francisco.

This study offers more motivation for women, and for doctors to ask moms and expectant moms about smoking, Oh said in an interview.

"Pregnancy is a great opportunity for smoking cessation," he said.

Smoking during pregnancy is linked to increased risks of miscarriage, low birth weight, certain birth defects and other pregnancy complications.

As for asthma, many studies have found that secondhand smoke may worsen children's asthma symptoms, or possibly raise their risk of developing the lung disease in the first place. The same risks have been linked to moms' prenatal smoking.

But, Oh's team says, it has not been clear how much of an impact prenatal smoking might have on kids' asthma symptoms later in life, independent of any current exposure to secondhand smoke.

HIGHER RISK AMONG POOR MINORITIES

For their study, the researchers focused on 2,481 black and Hispanic kids between the ages of 8 and 17 who all had asthma and were mostly from low-income families.

In the U.S., poor, minority children are at particular risk of asthma. About 16 percent of low-income black children have asthma, versus the national prevalence of 9 percent, according to the U.S. Centers for Disease Control and Prevention.

In this study, almost 19 percent of African-American moms smoked at some point during pregnancy, as did 5.5 percent of Hispanic moms.

Overall, their kids were at greater risk of poor asthma control later in life, even when childhood secondhand-smoke exposure was taken into account -- as well as other factors like a child's age and asthma medication use.

About 30 percent of Hispanic kids and 38 percent of black kids had poorly controlled asthma symptoms -- and the risk was 50 percent for those exposed to smoking in the womb, versus unexposed kids.

"There are measurable effects even years down the road," Oh said.

The findings do not, however, prove that prenatal smoking, itself, causes more-severe asthma symptoms later in life. They can only point to a correlation.

But there is lab research, in animals and human cells, suggesting there could be a direct effect, Oh pointed out.

Fetal exposure to tobacco smoke may, for example, impair early lung development, or have lasting effects on the activity of certain genes.

The bottom line, according to Oh, is that there is already a host of reasons for pregnant women to quit smoking for good, and this may be one more.

"This study provides more impetus for healthcare providers to ask about smoking at each visit," he said.

Some pregnant women may be able to quit with behavioral counseling. In some cases, a doctor may prescribe nicotine replacement therapy or other medication.

source: interaksyon.com