Research has taken place at Washington University into what is the optimum time spacing between pregnancies for healthy babies. The results have been published in the American Journal of Obstetrics and Gynecology. The results indicated that a gap of six months or less between pregnancies can lead to to a 41% increase in the risk of a premature birth, a gap of six months to a year can lead to a 14% increase in the risk of a premature birth but with a gap of over 1 year there is no increase in risk. This is obviously a particular issue with those who have already had a premature birth.

Previous research from Bogota in Columbia supported this and also said that babies born after a gap of six months or less between pregnancies were 61% more likely to be underweight at birth. This study also said that mother who had a gap of at least five years between pregnancies were up to 43% more likely to have health problems.

The general summary is that a gap of between 20 and 40 months between giving birth and conceiving the next child is ideal.

Studies offer insight into timing of subsequent pregnancies