PREGNANT women who smoke and have premature babies are three times more likely to develop cardiovascular disease, a new study has warned.
Smoking and having a premature baby both carry an independent, increased risk of getting heart disease but women who smoke and have premature babies face a greater risk.
Fertility treatment is pushing up rates of pre-term birthDr Anh Ngo
Research found that mothers who smoked and had a premature baby had a 3.35-times greater risk of cardiovascular disease – CVD – than non-smokers with normal births.
Women are already three times more likely to die of CVD than breast cancer. It accounted for almost 160,000 deaths in the UK in 2011.
CVD covers both disease of the heart and arteries.
The study by the University of Sydney argued that as premature births increase, because of fertility treatment, women should be warned of the dangers of CVD in later life.
The study was the first to examine the risk of both smoking and premature pregnancies to CVD risk.
Dr Anh Ngo said: “Smoking and pre-term birth are established risk factors for maternal CVD.
“Fertility treatment is pushing up rates of pre-term birth and smoking in pregnant women remains high, so knowledge of the impact of these conditions on CVD is important for prevention efforts.
“Smoking and pre-term birth synergistically increase maternal cardiovascular disease risk. When these two conditions coexist in the same individual, they then interact to produce a joint effect on maternal CVD risk that is 29 per cent greater than the sum of effects when they act alone.
“Women who smoke and have a pre-term birth more than triple their risk of cardiovascular disease.”
The study, published in the European Journal of Preventive Cardiology, looked at the natal records of 902,008 mothers during 1994 to 2011 and subsequent hospital admissions for CVD or death from CVD.
Analyses were conducted to compare the risk for CVD among mothers classified according to smoking and preterm birth.
It discovered that the CVD risk was even greater in smoking mothers with more severe or recurrent pre-term births.
Dr Ngo said: “Our research shows for the first time that smoking and pre-term birth interact to create a greater CVD risk than either risk factor on its own.
“One explanation could be the stress of caring for a preterm infant which may lead to unhealthy behaviours such as smoking, which increases the likelihood of future pre-term births.
“Stress itself causes metabolic disorders, atherosclerosis and ultimately CVD.
“Smoking women who seek assisted reproductive technology should be counselled about their risk for pre-term birth and CVD in later life so that they can make an informed decision.
“Smoking women who stop smoking when planning to get pregnant will receive dual protection.
“They will avoid the increased risk of having a pre-term birth and they will avoid the elevated risk of getting cardiovascular disease when they reach an older age.”