Ans. C: 18-22 weeks Routine USG at 18-22 weeks gestation has the following effects 1) reduces the incidence of post-term pregnancy (39%) and rates of induction of labour for post-term pregnancy, 2) increases early detection of multiple pregnancy (92%), 3) increases early detection of major fetal anomalies when termination is possible, 4) no significant differences in the clinical outcomes such as perinatal moality and 5) reduces neonatal admission to special care baby unit (14%)