Sample size

An evaluation of clinical studies using oral dydrogesterone, micronized progesterone capsules or gel for treatment in IVF predicted a ~35% pregnancy rate at 12 weeks of gestation (Ludwig et al., 2002; Kleinstein, 2005; Ganesh et al., 2011). With a non-inferiority margin of 10%, it was estimated that a sample size of 479 subjects per treatment arm would provide 90% power to demonstrate non-inferiority, should there be no difference in pregnancy rate at 12 weeks of gestation between the two treatment groups. With the addition of a dropout rate of 10%, a total sample size of 533 subjects per group would be required, or a total sample size of 1066 study subjects.