Mothers who give birth to two children within an 18-month period may increase their risk of having a premature baby, according to a new study.
This is the finding of a study carried out in the US, using data relating to 454,716 births recorded by the Ohio Department of Health.
All the births took place over a six-year period, with the primary focus of the investigation being to examine the length of interpregnancy interval (IPI). For the sake of the study, this was defined as the time between one birth and the next conception.
It was found that mothers with a shorter IPI were more likely to give birth prematurely (before 39 weeks of gestation), with 53.3 per cent of women with an IPI of 12 months or less in this position, in contrast to 37.5 per cent of those with an optimal IPI.
Giving birth before 37 weeks of pregnancy was also more common in women with a shorter IPI.
Interestingly, this was found to be a more prevalent occurrence in black women, with 26.4 per cent having an IPI of one year or less, compared to mothers of other races, where the figure was just 8.7 per cent.
In addition, black mothers were more likely to give birth prematurely overall, with a rate of 11.3 per cent, in significant contrast to the statistic for other ethnicities, which was 6.8 per cent.
Co-author of the study and assistant professor in maternal-foetal medicine at the University of Cincinnati College of Medicine Emily DeFranco commented: 'Short interpregnancy interval is a known risk factor for preterm birth. However, this new research shows that inadequate birth spacing is associated with shorter overall pregnancy duration.
'This study has potential clinical impact on reducing the overall rate of preterm birth across the world through counselling women on the importance of adequate birth spacing, especially focusing on women known to be at [an] inherently high risk for preterm birth.'
The paper authors suggest women should be educated about the importance of increasing their IPI in order to protect their own health and that of their baby.
Read the abstract here