In the 1990s one in four IVF births were twins. Now, a new report from the UK shows that the number of multiple births from IVF has reached a low of 6%, that is just one in twenty, which is a significant decrease. The report by the Human Fertilisation and Embryology Authority (HFEA), details how the multiple birth rate has reduced most in two different age ranges:

  • Under 35 years the number of multiple births dropped from 27% in 2007 to 6% in 2019
  • Over 44 the number of multiple births dropped from 31% in 2007 to 5% in 2019.

Substantial growth in IVF cycles

The same period has also seen a steady growth in use of IVF together with an improvement in IVF success rates. For instance, in 1991 there were 1,238 successful IVF births in the UK, that number grew to 390,000 in 2021.

Julia Chain, Chair of the HFEA said, “This is a major success for UK healthcare. Multiple births can be dangerous for both patients and unborn babies and can put an additional burden on the NHS. Multiple births were the biggest single health risk from IVF treatment and that is why we have campaigned for this since 2007 working closely with health professionals and fertility clinics. The numbers of babies born from IVF has continued to rise, confirming that transferring only one embryo does not impact on a patient’s chance of having a baby.”

Multiple birth risk

The main risk posed by multiple births arises because these babies tend to be born early, preterm’ is defined as under 37 weeks. About 60% of IVF twin babies are pre-term compared to around only 10% of IVF single babies. As well as this problem multiple foetuses also carry a higher risk of other health problems for mothers and babies, such as late miscarriage, high blood pressure and still birth.

Ms. Chain also sounded a note of caution about complacency, particularly as the report highlighted some other important issues such as ethnic discrepancies. Multiple births and multiple embryo transfers were more common among Black patients than other ethnic groups, the average multiple birth rate for Black patients was 12%, compared to 10% across all ethnic groups.

Level playing field still needed

She concluded, “The lower number of multiple births should be celebrated but we cannot be complacent as we know this is not the case in every fertility clinic. We will continue to monitor multiple birth rates from fertility treatment and encourage clinics to review their multiple birth strategies, particularly in relation to patients from ethnic minority groups as we want to achieve a level playing field for all patients.”

Please click here for more information.