Most common cause of first trimester abortion is:

Ans. is a, i.e. Chromosomal abnormalitiesRef. Dutta Obs. 7/e, p 159,160; COGDT 10/e, p 259; Williams Obs. 23/e, p 215Abortion is spontaneous termination of pregnancy before 22 weeks or weight of fetus less than 500 gm.Incidence: About 15% of all conceptions end up in spontaneous abortions. Out of these 80% occur before 12 weeks i.e. in 1st trimester and among these 50-75% are due to chromosomal anomalies (Germplasm defect).