A Chinese study published in _The BMJ_ suggests that fresh embryo transfer may be a better option than a frozen one for women with a low chance of IVF success.
Women may have a reduced chance of conception through IVF because of older age or low quality or quantity of eggs, or certain underlying conditions. The number of women with low prognosis for IVF success has been increasing.
The standard method in IVF is the "freeze-all" strategy, where all suitable embryos are frozen before transfer. While studies have shown similar IVF success rates with both fresh and frozen embryo transfers in women with a good prognosis, it was unclear whether this applied to women with a low prognosis.
To investigate, researchers compared live birth rates following fresh versus frozen embryo transfers in 838 women aged 33-34 with a low IVF success prognosis. The results showed that 40 per cent of women in the fresh embryo transfer group had a live birth, compared to 32 per cent in the frozen embryo transfer group.
The frozen embryo group also had a lower pregnancy rate than the fresh embryo group—39 per cent versus 47 per cent and a lower cumulative live birth rate after further embryo transfers within one year of randomisation—44 per cent versus 51 per cent. Pregnancy loss occurred in 31 per cent of women in the frozen group, compared with 23 per cent in the fresh group. There were no differences in birth weight, obstetric complications or illness risk in newborns between the two groups.
“Fresh embryo transfer may be a better choice for women with low prognosis for IVF in terms of live birth rate compared with frozen embryo transfer,” the study concluded.