Chromosomal Screening Improves IVF Pregnancy Rates
(HealthDay News) – Screening embryos produced by in vitro fertilization using array comparative genomic hybridization (aCGH) plus morphology improves pregnancy rates over screening by morphology alone in single embryo transfers.
To investigate the use of comprehensive chromosomal screening to select one embryo for single embryo transfer, Zhihong Yang, PhD, from the Pacific Reproductive Center in Torrance, CA, and colleagues randomly assigned 103 women (<35 years old) undergoing in vitro fertilization to screening of day-five blastocysts by morphology and aCGH or by morphology alone. A single blastocyst was transferred on day six. Four hundred twenty-five blastocysts were biopsied and analyzed via aCGH for 55 women, and 389 were examined microscopically for the 48 women in the morphology-alone group.
The researchers found that 44.9% of the blastocysts analyzed by aCGH were aneuploid. Compared with morphology alone, the aCGH group had significantly higher clinical pregnancy rates (70.9 vs. 45.8%; P=0.017) and significantly higher ongoing pregnancy rates (after 20 weeks, 69.1 vs. 41.7%; P=0.009). No twin pregnancies were identified.
"Embryos randomized to the aCGH group implanted with greater efficiency, resulted in clinical pregnancy more often, and yielded a lower miscarriage rate than those selected without aCGH," Yang and colleagues conclude. "Although these initial single embryo transfer data are encouraging, a multi-center randomized clinical trial with a larger sample is planned to validate these preliminary findings."