The rate of embryo losses for an in vitro fertilization (IVF) technique in which sperm is injected directly into an egg is similar to that seen with conventional IVF, Italian researchers report.

For some infertile couples who are not successful with the usual IVF procedure, pregnancy can be achieved with so-called intracytoplasmic sperm injection, but there has been concern that the process might be damaging to resulting embryos.

To look into this, researchers studied 543 women who underwent conventional IVF and 419 who underwent IVF with sperm injection at a public clinic in Italy.

Embryo loss was determined by subtracting the number of embryos detected by ultrasound during the second trimester from the number detected during the first.

The early loss rates of quadruplets, triplets, twins, and singletons after each procedure were similar, Dr. Isaac Blickstein, from the Kaplan Medical Center in Rehovot, Israel, and colleagues report in the medical journal Fertility and Sterility.

The highest loss rate - 33.3 percent - occurred among triplet embryos produced by conventional IVF, whereas the lowest rate - 18.6 percent - was for twins resulting from IVF plus sperm injection.

Older women (35 years of age or older) who underwent conventional IVF experienced higher loss rates than younger women, but this was not seen among women whose embryos were produced by sperm injection.

“Our observations suggest that there is no difference between loss and/or survival rates of multiple gestations after conventional IVF or intracytoplasmic sperm injection,” the authors conclude.

SOURCE: Fertility and Sterility, December 2004.