Exercising During Pregnancy Helps Maintain Child's Blood Pressure Later In Life
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Pregnant women who exercise regularly may be helping their babies beat high blood pressure in later life, say researchers.
They found the children of mothers who were physically active – especially in the last three months of pregnancy – had significantly lower blood pressure when they reached the age of 10. The finding even applied to babies with lower birth weight who are known to have a greater risk of high blood pressure later in life.
The US study is the first to show the exercise habits of mothers-to-be may lower a child’s chances of high blood pressure, a key factor in cardiovascular health.
James Pivarnik, lead author and kinesiology professor at Michigan State University, said: ‘We looked at a range of normal birth weight babies, some falling at the lower end of the scale, and surprisingly we found that this lower birth weight and higher blood pressure relationship in these offspring is not supported if the women were physically active.
‘The connection was disrupted, indicating that exercise may in some way alter cardiovascular risk that occurs in utero (in the womb).’
Research suggests babies who are small at birth tend to have more coronary heart disease and strokes later in life, but the latest study found this tendency may be altered through greater activity by the mother while pregnant.
The researchers initially evaluated 51 women over a five-year period based on physical activity such as running or walking throughout pregnancy and post-pregnancy.
In a follow up to the study, they found that regular exercise in a subset of 12 women, particularly during the third trimester, was associated with lower blood pressure in their children.
Those children whose mothers exercised at recommended or higher levels of activity had significantly lower systolic blood pressures at 8 to 10 years old.
Prof Pivarnik said ‘This told us that exercise during critical developmental periods may have more of a direct effect on the baby.
‘This is a good thing as it suggests that the regular exercise habits of the mother are good for heart health later in a child’s life’ he added.
The study, published in the Journal of Sports Medicine and Physical Fitness, concluded that regular physical activity by the mother is associated with ‘an alteration in the relationship between birth weight and systolic blood pressure’.
The researchers say their findings support the theory of genetic pre-programming of a child’s health characteristics while in the womb.
This phenomenon is linked to what’s known as the fetal origins hypothesis. The theory suggests if something strenuous happens to a mother and her unborn child during critical growth periods in the pregnancy, permanent changes can occur that can affect the health of the baby.
Advice for mums-to-be on the NHS Choices website says exercise is not dangerous for the baby and there is some evidence that active women are less likely to experience problems in later pregnancy and labour.
Pregnant women are currently recommended to take 30 minutes of moderate intensity exercise per day.
However, research suggests that pregnant women who exercise for more than an hour a day are at greater risk of developing pre-eclampsia, a condition that can threaten mother and baby.
NHS Choices says: ‘As a general rule, you should be able to hold a conversation as you exercise when pregnant. If you become breathless as you talk, then you’re probably exercising too strenuously.’