Abdominal trauma in pregnancy. When is fetal monitoring necessary? The type and duration of observation and monitoring of mother and fetus after abdominal trauma are dependent on gestational age and severity of trauma. Fetal monitoring is usually not required when the fetus is not viable; the primary consideration is the safety of the mother. When the fetus is viable, 24-hour inpatient fetal monitoring is indicated in cases of major trauma, even when no symptoms of injury are obvious. 