The overall success rate of IVF does not appear to be reduced by sequential treatment with modified natural cycle IVF (MNC-IVF) and controlled ovarian stimulation IVF (COS-IVF), and the twin pregnancy rate is low, conclude Dutch researchers.
M. Pelinck, from University Medical Center Groningen, and colleagues followed-up 268 patients from an earlier study who had been offered nine cycles of MNC-IVF, assessing ongoing pregnancy and live birth rates, along with time-to-pregnancy after COS-IVF following MNC-IVF.
By the start of COS-IVF, 109 patients, aged an average of 34.2 years, remained in the study.
For COS-IVF following MNC-IVF, the actual observed cumulative ongoing pregnancy, live birth, and term live birth rates were 51.5 percent, 50.0 percent, and 43.3 percent, respectively, of which 8.0 percent, 6.7 percent, and 2.6 percent, respectively, were twins.
In addition, the cumulative ongoing pregnancy rate, including treatment-independent pregnancies, was 56.7 percent. The median time to ongoing pregnancy was 28.8 weeks.
The team says: "In conclusion, sequential treatment with MNC-IVF followed by COS-IVF does not appear to compromise overall success rates, while twin pregnancy rate is very low. Because of the patient-friendly and low-risk profile of MNC-IVF, this seems an appropriate strategy."
