Taking history of smoking in pregnant woman and following its effect on fetus is what -
Ans-B i.e., Prospective cohort o Prospective cohort study is one in which the outcome (e.g. disease) has not occurred at the time of investigation begins.o In the given question, the outcome has not occurred at the time of investigation begins. Only history of risk factor exposure (smoking) is taken. Then outcome (effect on fetus) is followed in prospective.o This is classical prospective cohort study.Types of cohort studieso Prospective cohort study'Known as 'Current cohort study' or 'Concurrent cohort study'Outcome has not yet occurred when the study has begun: Only exposure has occurred; we look for development of same disease in both exposed and non-exposed groupsExamples :- Framingham heart study, Doll & Hills prospective study on smoking & lung Cancer.o Retrospective cohort study :Known as 'Historical cohort study ' or 'Non-concurrent cohort study 'Combines advantages of both Cohort study and Case control studyBoth exposure as well as outcome have occurred when the study has begun: First we go back in time and take only exposure into consideration (cohorts identified from past hospital/ college records), then look for development of same disease in both exposed and non-exposed groupsSample size required is same as that of prospective cohort studyUsually used in occupational cancer studiesExamples :- Effect of fetal monitoring on neonatal death; PVC exposure and angiosarcoma of liver.o Combined prospective-retrospective cohort study :Known as 'Mixed cohort study'Combines designs of both prospective cohort study and retrospective cohort studyBoth exposure as well as outcome have occurred when the study has begun: First we go back in time and take only exposure into consideration (cohorts identified from past hospital/college records), then look for development of same disease in both exposed and non-exposed groups: later cohort is followed prospectively into future for outcomeExamples Court-Brown & Doll Study on effects of radiation therapy.
Case control
Prospective cohort
Retrospective cohort15.
Case report