Primary Infertility – those patients who have never conceived i.e. G0 P(0+0)
Secondary Infertility – indicates previous pregnancy but failure to conceive subsequently i.e. P(1+0) , P(0+1)
Infertility have affected up to 15% of reproductive-aged couples worldwide. In India prevalence of ever experienced primary and secondary infertility are 6.6% & 2.1% respectively.