Spontaneous embryonic loss rates in twin and singleton pregnancies after transfer of top- versus intermediate-quality embryos.

OBJECTIVE: To determine whether embryo quality is associated with early spontaneous loss rates in twin and singleton pregnancies after IVF/intracytoplasmic sperm injection (ICSI).

DESIGN: Retrospective, single center analysis.

SETTING: The Center of Reproductive Medicine, Arcispedale Santa Maria Nuova, Reggio Emilia, Italy.

PATIENT(S): Women undergoing IVF/ICSI and two- or three-embryo transfer of intermediate- and top-quality embryos.

INTERVENTION(S): First-trimester sonography at 6 to 7 weeks to determine number of embryos with positive heartbeat. Number of embryos lost was calculated from a second-trimester sonogram.

MAIN OUTCOME MEASURE(S): Rates of total pregnancy loss, as related to embryo quality, initial number of embryos, maternal age <35 or > or =35 years, and IVF procedure.

RESULTS: A total of 94 losses (23.1% of 407 pregnancies) were counted, with similar proportions in pregnancies after transfer of intermediate- or top-quality embryos. Neither the mode of IVF procedure nor the number of transferred embryos affected the loss rate. In contrast, the loss rate was significantly higher in older mothers after transfer of intermediate-quality embryos (odds ratio [OR 2.4], 95% confidence interval [CI] 1.1-5.5). Losses among singletons were significantly higher compared with losses among twins (OR 2.5, 95% CI 1.1-6.0), but this was observed in top-quality embryos only.

CONCLUSION(S): Top-quality but not intermediate-quality ETs are associated with lower early spontaneous loss rates among twin pregnancies after IVF/ICSI.