• Abortion is the expulsion or extraction from its mother of an embryo or fetus at less than 20 weeks, or weighing 500 g or less when it is not capable of independent survival.
• Viability is a stage when fetus becomes capable of living independently, this has been fixed administratively at 28 weeks, when the fetus weighs approximately 1000g.
• Early Pregnancy Loss: Currently ACOG (2017) defines this as a nonviable intrauterine pregnancy with either an empty gestational sac or gestational sac containing an embryo or fetus without fetal heart Sounds (FHS) within the first 12 6/7 weeks of gestation.
→ Period of viability depends on the medical facilities of a country and hence varies.
→ As per USA-20 weeks; WHO-24 weeks; In India: beyond 28 weeks.
→ Weight of fetus @ 20weeks-300gm
→ WHO definition– Pregnancy loss with wt. of fetus <500gm (@ 24 weeks of pregnancy)