Fewer twins

23/12/2008 15:00

Multiple births accounted for 3,062 babies born in the Netherlands in 2007. This is down from 3,762 in 2002. Fewer twins in particular are being born. The fall in the number of twin births is connected with developments in in vitro fertilisation (IVF).

Multiple births

Multiple births

IVF accounts for most of increase and decrease

The number of multiple births has shown much stronger fluctuations in recent decades than the total number of births in the Netherlands. The number of births rose by 5 percent between 1982 and 2007, while the number of babies born in multiple births rose by more than 60 percent. The rise in vitro fertilisation (IVF) and changing policies regarding embryo replacement have played a large part in these differences.

Recent drop in twin births

Until the 1980s, triplets, quadruplets and quintuplets accounted for around 1 percent of total multiple births in the Netherlands. In the beginning of IVF, four or five embryos were placed with their mothers, and as a result triplets and higher order multiple births were more common around 1990. The later practice of replacing two embryos resulted in fewer triplets and higher order multiple births, but not in fewer twins. More recently, doctors have starting replacing only one embryo, so that the number of twins is also falling.

Estimated number of identical and non-identical twin births

Estimated number of identical and non-identical twin births

One in thirty babies born in multiple birth

In 1982 around one in 45 newborns were born in a multiple birth. Around 2000 this share was one in 27. In 2007 it had dropped back to one in 30.

Number of identical twins constant

About one in every 200 births are identical twins. This share has hardly changed in the course of time.  The increase and decrease in twin births is largely the result of non-identical twins born as a result of IVF.

Share of newborns in multiple births

Share of newborns in multiple births

Joop Garssen