Twins in decline for first time in a decade, ONS data reveals, following changes to IVF rules

Twins, triplets and quadruplets are in decline for the first time in a decade, official statistics show, following changes to IVF rules.

The Office for National Statistics (ONS) today published data revealing that out of every 1,000 women giving birth, 15.4 had a multiple birth in 2018. This was the lowest multiple maternity rate since 2007, when the rate was 15.3.

The 2018 data also marks a decrease in the multiple maternity rate for the third consecutive year (15.9 for 2016, and 15.8 for 2017, respectively).

There were 9,873 women who gave birth to twins in 2018, and 132 women gave birth to triplets or above.

The British Pregnancy Advisory Service (BPAS) said that the reduction in multiple pregnancies is likely to be as a result of the latest National Institute for Health and Clinical Excellence (NICE)

guidelines on IVF (published 2013) which recommend that women under 37 should only have one embryo transferred in their first cycle of IVF.

Clare Murphy, Director of External Affairs at BPAS, said: “Multiple birth rates following IVF have historically been very high, at one stage up to 20 times higher than natural conception. However, multiple maternities represent the single greatest risk in IVF treatment since they can lead to higher complication rates.

“It is great to see that initiatives to reduce them have had an impact, but crucially without reducing the overall success rate of IVF - meaning women can access this treatment safely while retaining the chances of a healthy pregnancy.”

Babies born from multiple births tend to have lower birthweights than those born individually.

Multiple pregnancies are also associated with a higher risk of stillbirth, infant deaths and child disability. However, the ONS said that while most multiple births occur naturally, many occur because of fertility treatment. It is estimated that IVF conceptions are seven times more likely to result in a multiple birth than natural conceptions.

Since the first successful full-term pregnancy through IVF in 1978 and the subsequent rise in assisted fertility treatments, the multiple maternity rate for women aged 45 years and over increased from 15.2 maternities with multiple births per 1,000 maternities in that age group in 1978, to a peak of 115.5 in 2012.