What are the management and evaluation steps for a pregnant woman at 37 weeks gestation experiencing abdominal cramps after a fall, with a normal fetal heart rate?

Management of Abdominal Cramps After Fall at 37 Weeks Gestation with Normal Fetal Heart Rate

All pregnant trauma patients at 37 weeks gestation with a viable fetus should undergo electronic fetal monitoring for at least 4 hours, and those with abdominal pain, uterine tenderness, or significant mechanism of injury should be admitted for 24-hour observation. 1

Immediate Assessment and Monitoring

Initial Evaluation Priority

• The pregnant woman's stabilization is the first priority, followed by fetal assessment once maternal stability is confirmed. 1 At 37 weeks with a viable fetus, fetal heart rate monitoring should be initiated as soon as feasible after maternal assessment. 1

• Perform a focused physical examination looking specifically for: uterine tenderness, vaginal bleeding, sustained uterine contractions (>1 per 10 minutes), rupture of membranes, and signs of placental abruption. 1 These are the key adverse factors that determine need for extended monitoring.

Fetal Monitoring Requirements

• Continuous electronic fetal monitoring must be performed for a minimum of 4 hours for all pregnant trauma patients at ≥23 weeks gestation. 1, 2 This is the evidence-based standard regardless of initial presentation.

• Normal fetal heart rate monitoring combined with absence of early warning symptoms (vaginal bleeding, uterine contractions, abdominal/uterine tenderness) has a 100% negative predictive value for adverse outcomes directly related to trauma. 2 However, the presence of abdominal cramps in your patient constitutes an early warning symptom requiring extended evaluation.

Criteria for Extended 24-Hour Admission

Your patient meets criteria for 24-hour admission based on the presence of abdominal pain (cramps) following trauma. 1 The specific adverse factors requiring admission include:

• Uterine tenderness 1
• Significant abdominal pain 1
• Vaginal bleeding 1
• Sustained contractions (>1 per 10 minutes) 1
• Rupture of membranes 1
• Atypical or abnormal fetal heart rate pattern 1
• High-risk mechanism of injury 1

Even though the fetal heart rate is currently normal, the presence of abdominal cramps after a fall constitutes significant abdominal pain and warrants the full 24-hour observation period.

Essential Laboratory and Imaging Studies

Maternal Blood Work

• Obtain complete blood count, coagulation panel including fibrinogen level. 1 A fibrinogen level <200 mg/dL is an additional adverse factor requiring admission. 1

• For Rh-negative patients: administer anti-D immunoglobulin to all Rh-negative pregnant trauma patients and perform Kleihauer-Betke testing to quantify maternal-fetal hemorrhage and determine need for additional doses. 1 For Rh-positive patients, Kleihauer-Betke testing is not recommended as it rarely affects management. 2

Ultrasound Evaluation

• All pregnant trauma patients admitted for monitoring >4 hours should have an obstetrical ultrasound prior to discharge. 1 This ultrasound should assess fetal well-being, amniotic fluid volume, and placental location.

• Be aware that ultrasound is not sensitive for diagnosing placental abruption, so management should not be delayed pending ultrasound confirmation if clinical suspicion is high. 1 Clinical signs (vaginal bleeding, uterine tenderness, sustained contractions, abnormal fetal heart rate) take precedence.

Critical Pitfalls to Avoid

Do Not Rely on Reassuring Initial Findings Alone

While normal fetal heart rate monitoring is encouraging, early warning symptoms (abdominal cramps in this case) have only 52% sensitivity and 48% specificity for adverse outcomes. 2 The key is that when monitoring is normal AND early warning symptoms are absent, the negative predictive value is 100%—but your patient has symptoms. 2

Placental Abruption Surveillance

Placental abruption occurs in 1.58% of pregnant trauma patients and is the most common cause of fetal death after trauma. 2 The incidence is highest with motor vehicle accidents. 2 Continuous monitoring during the observation period is essential as abruption can evolve over hours.

Monitoring Evolution

Repetitive monitoring over several days in previous studies did not identify patients whose tracings evolved from normal to abnormal. 2 This supports the 4-24 hour monitoring window rather than prolonged hospitalization, but the initial observation period must be completed.

Discharge Criteria and Follow-Up

The patient may be discharged after 24 hours if:

• Fetal heart rate monitoring remains reassuring (Category I: normal baseline 110-160 bpm, moderate variability, no late or variable decelerations) 3
• No vaginal bleeding develops 1
• Uterine contractions resolve or remain <1 per 10 minutes 1
• Abdominal pain/cramping resolves 1
• Ultrasound shows no evidence of abruption or other complications 1
• Fibrinogen level remains ≥200 mg/dL 1

Provide clear discharge instructions to return immediately for vaginal bleeding, regular contractions, decreased fetal movement, or worsening abdominal pain. 1

Gestational Age Considerations

At 37 weeks gestation, the fetus is term and delivery would not be considered preterm. 1 If concerning findings develop during monitoring (Category III fetal heart rate pattern, signs of abruption with maternal or fetal compromise), expedited delivery should be considered as neonatal outcomes at this gestational age are excellent. 1