||Perinatal epidemiology provides the clinician
working in antenatal care information about risk factors for adverse pregnancy outcome.
However, many studies do not take account of dependencies between individuals in the study
populations, for instance between siblings. Such dependencies may modify risk to a
considerable degree. At least half of the appointments in antenatal care are with women
who have previously been pregnant and given birth. The information these mothers can
provide through their previous experiences is of great importance for the clinician when
assessing the present pregnancy.