Pregnant and smoking? Read this!
February 25, 2010 by Raquel
Filed under HEART AND STROKE
Pregnant, yet still smoking? Well, this latest report from the experts might motivate you to quit.
Swedish researchers compared the blood pressure of babies of moms show smoked during pregnancy, and babies of moms who did not. The results are really bad news for smoking moms and even worse news for their babies. Why bad news? Because these babies tend to suffer from a so-called circulatory dysfunction which results in abnormal control of the blood pressure during repositioning.
When we stand up, the heart rate normally increases, blood vessels constrict to keep the blood supply to the organs of the upper part of the body especially the brain and the heart, the blood pressure increases slightly.
In the first few months of their lives, babies are not able to change positions or sit/stand upright and have to be lifted for repositioning. During repositioning, the baby’s body, too, has to cope with the change in position with change in blood pressure.
The study involved 19 babies of non-smoking couples and 17 babies of moms who smoked 15 sticks of cigarettes per day on average. Both groups of babies were of normal weight at birth and were breastfed. A test for blood pressure control is by tilting the babies upright during sleep.
In this research, the babies were tilted up to an angle of 60 degrees and then returned to their lying position again. Blood pressure and heart rates were then measured during sleeping, during tilting, and after returning to the original lying position. The tilting test and the measurements were performed when the babies were aged 1 week, 3 months, and 1 year. The results of the study show:
- Babies at age one week who were not exposed experience a 2% increase in blood pressure when tilted. At age one year, this increase in blood pressure is up to 10%, a normal increase correlated to the increase in size and mobility of the baby.
- Babies who were exposed to tobacco in utero exhibit the opposite trend in blood pressure during tilting. A 10% increase was observed during the first week, which decreases down to 4% at age 12 months.
- The researchers also observed that the heart rates of the exposed babies were abnormal and highly exaggerated in response to tilting at ages 3 months and one year.
- When sleeping undisturbed, diastolic blood pressures of exposed babies were higher at 3 months, and the heart rates were 20% slower at 1 year compared to non-exposed babies.
- When upright babies were returned abruptly to their lying position, blood pressure in non-exposed babies goes back to normal; blood pressure of tobacco-exposed babies goes up.
According to lead author Dr. Gary Cohen, senior research scientist in the Department of Women and Child Health at the Karolinska Institute in Stockholm, Sweden:
In other words, the circulatory system of tobacco-exposed babies is not functioning properly and is hyperreactive in the first days of life, but becomes underreactive and less effective with time. The circulatory dysfunction and poor blood pressure control have some consequences later in life, including susceptibility to hypertension and other cardiovascular problems.
