Conceiving again too soon increases the risk of premature labour, stillbirth and even maternal death, scientists discover.
A new study now says that couples should wait at least a year after their baby is born before trying for another child.
According to experts from harvard, a gap of 12-to-18 months between pregnancies was shown to be the safest for both mother and child.
Experts said last night the findings are particularly important for older mothers, who tend to try to have several children in a short period to complete their family before their fertility declines.
Study leader Dr Laura Schummers, whose findings are published in the JAMA Internal Medicine journal, said that the study found increased risks to both mother and infant when pregnancies are closely spaced, including for women older than 35.
She added, “The findings for older women are particularly important, as older women tend to more closely space their pregnancies and often do so intentionally.”
The researchers found the risks were different according to a woman’s age.
For those over 35, a short gap between pregnancies was particularly dangerous for the mother herself.
For younger women, the risk to the mother of a short gap between pregnancies was negligible, but there was an increased risk of the baby being born premature.
Among women over 35 who conceived six months after a previous birth, the researchers found a 1.2 per cent risk of maternal death or severe harm.
If they waited 18 months between pregnancies, the risk was more than halved to 0.5 per cent.
Scientists believe a short gap between pregnancies does not leave the body enough time to recover.
On the other hand, leaving it too long brings the risk of complications associated with an ageing mother.