Women often wonder what the “right” length of time is after giving birth before getting pregnant again. A recent Canadian study suggests 12-18 months between pregnancies is ideal for most women.

But the period between pregnancies, and whether a shorter or longer period poses risks, is still contested, especially when it comes to other factors such as a mother’s age. It’s important to remember that in high-income countries most pregnancies go well regardless of the gap in between.

What is short and long

The time between the end of the first pregnancy and the conception of the next is known as the interpregnancy interval. A short interpregnancy interval is usually defined as less than 18 months to two years. The definition of a long interpregnancy interval varies – with more than two, three or five years all used in different studies.

Most studies look at the difference every six months in the interpregnancy interval makes. This means we can see whether there are different risks between a very short period in between (less than six months) versus just a short period (less than 18 months).

Most subsequent pregnancies, particularly in high-income countries like Australia, go well regardless of the gap. In the recent Canadian study, the risk of mothers having a severe complication varied between about one in 400 to about one in 100 depending on the interpregnancy interval and the mother’s age.