Table II. Definitions of pregnancy outcomes.

	Definitions
Biochemical pregnancy	HCG >5
Clinical pregnancy	HCG >5, amniotic sac visible on ultrasound 6–8 weeks of gestation
Ongoing pregnancy	Amniotic sac present, beating heart 9–11 weeks of gestation
Implantation	Amniotic sac present (clinical pregnancy)
Implantation rate	Number of amniotic sacs per patient/number of embryos transferred per patient
Miscarriage	Amniotic sac present at 6–8 weeks, no beating heart at 9–11 weeks
Birth rate	All births
Live birth rate	All live births