Asian and black women who undergo in IVF are less likely to become pregnant than white or Hispanic women, according to new research presented last week at the American Society for Reproductive Medicine (ASRM) meeting in Philadelphia. Doctors at the University of Kansas-Wichita showed that while the average birth rate after IVF using fresh, rather than frozen eggs is 25.7 per cent, this figure conceals wide variation in the success rates for different ethnic groups.
The researchers studied records for more than 80,000 IVF treatment cycles carried out between 1999-2000, in which the ethnic origin of the patient was reported. They found that the birth rate was 18.7 per cent for black women, 20.7 per cent for Asian women, 26.3 per cent for white and 26.7 per cent for Hispanic women. Black women also had the highest miscarriage rate of 22 per cent, compared to 13.9 per cent for white women, 16.4 per cent for Hispanic and 16.2 per cent for Asian women.
The team are not sure of the reasons for these differences, although one possibility could be the higher rate of fibroid and uterine disease in black women. 'It's frustrating', said team leader David Grainger, adding that 'if you are 30 and black, your success rate is that of a white women aged 36'. He also said that the reason for lower success rates in Asian women was unclear, since they don't tend to have higher body weights, and have low smoking rates - two factors known to decrease the chances of successful IVF treatment.
Another US study presented at the meeting looked at records from 1,200 IVF treatment cycles, and confirmed that Asian women had a lower pregnancy rate than non-Asians. The research, carried out at the University of California, found that the birth rate for Japanese, Indian and Chinese patients is about 60 per cent that of white women. The team stressed that the differences did not apply to the chances of conceiving naturally. Marion Damewoood, president of the ASRM, said the findings were preliminary but important, and added: 'We need to further explore these apparent racial differences to see if we can better understand and hopefully address their causes'.