Pre‐implantation genetic diagnosis (PGD) for sickle cell disease (SCD) appears to be effective for preventing disease transmission, according to research published in the British Journal of Haematology.
SCD affects 300,000 neonates worldwide, and is associated with a reduced life expectancy. Noninvasive prenatal testing has a low sensitivity, while invasive testing carries a miscarriage rate of 1%. Although PGD is a good option in cases where the risk of infant SCD is high, previous studies have not evaluated its cumulative success rate.
For this cohort study, researchers analyzed cumulative outcomes among couples who decided to use PGD for SCD prevention. All data were obtained from an inner-London PGD tertiary referral center.
Between 2012 and 2017, 60 couples were referred to the center. The mean maternal and paternal ages were 33 and 37, respectively, the mean maternal body mass index was 25, and in 52 of the couples (80%), both mother and father were affected by SCD. In 3 of the couples (5%), the mother was affected and the father was a carrier; in 5 of the couples (8%), the father was affected and the mother was a carrier.
Overall, 70 fresh PGD cycles were initiated in all 60 included couples. The mean number of PGD cycles was 1.2 per couple, and a mean of 8 cycles did not reach biopsy stage. In all, there were 76 frozen embryo transfer (FET) cycles, with a mean of 1.3 FET cycles per couple.
There were 43 positive pregnancy tests overall (57% of FET cycles), with 42 clinical pregnancies (55% of FET cycles). Miscarriage occurred in 4 pregnancies (9%). Thirty-eight live births occurred, representing 54% of the fresh PGD cycles and 63% of couples who underwent PGD treatment.
“[C]arefully designed public health campaigns are required to highlight this important reproductive option and its high cumulative success rate, particularly when patients are able to utilise all the embryos created in the fresh cycle through multiple FET attempts,” the authors wrote.
Vali S, Mukhtar S, Nandi A, et al. Cumulative outcome of pre-implantation genetic diagnosis for sickle cell disease: a 5-year review [published online July 4, 2020]. Br J Haematol. doi: 10.1111/bjh.16930