Women who have suffered a miscarriage or undergone an abortion have three times the normal risk of giving birth to a baby with low birthweight subsequently, say researchers.
The study, based on data from the United States Collaborative Perinatal Project set up in 1959, is published in the Journal of Epidemiology and Community Health.
Low birthweight (under 2500 g) and premature birth (less than 37 weeks) are two of the major contributors to deaths among newborn babies and infants.
Researchers who assessed more than 45,500 mother and child pairs found that nearly 40pct of the mothers had one or two children and almost two thirds were between 20 and 29 years of age.
Rates of low birthweight and premature birth were highest among mothers who were black, young or old, poorly educated, and unmarried.
However, the researchers also found a strong link between miscarriage and abortion and an early or underweight birth in the subsequent child.
This was noted even after adjusting for other influential factors, such as smoking, high blood pressure and heavy drinking.
According to the researchers, women who had had one, two, or three or more miscarriages or abortions in the past are almost three, five, and 9 times as likely to give birth to an underweight child as those without previous miscarriages or abortions.
They also found that women who had one miscarriage or abortion were 67pct more likely to have a premature birth, while those who had had three or more were over three times as likely to do so compared with those with no history of miscarriage or abortion.
Based on this, they state that women and healthcare professionals should be aware of the potential risks of either abortion or miscarriage.