Using frozen embryos gets better results for mother and baby in IVF treatments, a study concludes.
The study showed that babies which grow from thawed embryos are less likely to be born preterm or underweight and have a lower risk of dying in the days after their birth.
Thawed embryos also reduced the risk of bleeding for the mother during pregnancy.
Existing research has also shown there is no difference in pregnancy rate whether fresh or frozen embryos are used, but experts from Aberdeen University reviewed 11 previous studies which followed more than 37,000 pregnancies from implantation of either fresh or thawed embryos to birth, and have concluded differently.
The Aberdeen University experts showed that when frozen embryos were used, there was a
- 30 per cent lower risk of bleeding during pregnancy,
- 30 to 40 per cent less chance of the baby being born underweight,
- 20 per smaller risk of it being born preterm and
- 20 per cent less likelihood of it dying shortly after birth.
Researchers put the increased reliability of frozen embryos down to the delay between removing the eggs from the mother and implanting it back in the mother after fertilisation.
The fact that only the healthiest embryos survive the freezing and thawing process could also increase the likelihood of the pregnancy going according to plan, it was claimed.
The study by Dr Abha Maheshwari of Aberdeen University was published in the Fertility Sterility journal and was presented at the British Science Festival in Aberdeen on Wednesday.
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