Most common abnormality for first trimester abortion is: (AIIMS Nov 2011)
|C||Placental and membrane abnormalities|
a. Abortion is the termination of pregnancy before the period of viability which is considered to occur at 28th week.
b. 10% of all pregnancies end in spontaneous abortions. 75% abortions occur before the 16th week and of these, about 75% occur before the 8th week of pregnancy.
c. The causes of abortion are usually divided into: (1) Ovular or fetal, (2) Maternal environment, (3) Parental factor and (4) Unknown.
d. The ovo-fetal factors usually operate in early fetal wastage. The defects include chromosomal abnormality (most common being autosomal trisomy), gross congenital malformation, blighted ovum (ovum without embryo) and hydropic degeneration of villi.