What are the steps for a per abdominal examination in a pregnant patient?

Per Abdomen Examination in a Pregnant Patient

The per abdominal examination in pregnancy should follow a systematic approach that includes inspection, palpation for fundal height and fetal position, auscultation of fetal heart tones, and assessment for uterine tenderness, peritoneal signs, or masses—with ultrasound serving as the primary imaging modality when pathology is suspected. 1

Systematic Examination Steps

Inspection

• Observe abdominal contour and symmetry to assess for distension, surgical scars, or visible fetal movements 1
• Evaluate skin changes including striae gravidarum, linea nigra, and any signs of trauma or bruising 2
• Note the position of the umbilicus which typically everts in the third trimester 3

Palpation Technique

• Position the patient in left lateral tilt (15-30 degrees) to prevent supine hypotension from inferior vena caval compression by the gravid uterus 3
• Assess fundal height by measuring from the pubic symphysis to the uterine fundus—this should correlate with gestational age in centimeters after 20 weeks 4
• Perform Leopold's maneuvers (after 28 weeks) to determine fetal lie, presentation, position, and engagement 4
• Palpate systematically for masses, organomegaly, or areas of tenderness outside the gravid uterus, recognizing that anatomical displacement occurs as pregnancy progresses 4, 5
• Assess for peritoneal signs including rebound tenderness, guarding, and rigidity—though these may be less pronounced in pregnancy due to abdominal wall stretching 6, 5
• Evaluate uterine tone and tenderness to detect potential placental abruption or uterine rupture if trauma is present 7

Auscultation

• Auscultate fetal heart tones using Doppler ultrasound, with normal fetal heart rate ranging from 110-160 beats per minute 4
• Listen for bowel sounds in all four quadrants, noting that decreased motility is physiological in pregnancy due to progesterone effects 4, 3

Critical Clinical Pitfalls

Anatomical Displacement Considerations

• The appendix migrates superiorly and laterally as the uterus enlarges, so appendicitis pain may not localize to McBurney's point in the second and third trimesters 4, 7
• Physiologic hydronephrosis occurs in >80% of pregnant patients (more commonly on the right), typically beginning in the second trimester, and should not be automatically attributed to pathology 8

When Physical Examination is Insufficient

• Ultrasound is the first-line imaging modality for acute abdominal pain in pregnancy, providing high sensitivity (99.7% specificity) for detecting clinically significant injuries and pathology without radiation exposure 1, 2, 5
• MRI without gadolinium is the second-line modality when ultrasound is nondiagnostic, as it avoids ionizing radiation and provides excellent soft tissue characterization 4, 5
• CT should not be delayed when early diagnosis is critical for maternal or fetal survival, as most diagnostic CT studies deliver far less than 20 mGy to the uterus 4, 8, 5

Common Causes Requiring Specific Examination Focus

Obstetric Emergencies

• Placental abruption presents with uterine tenderness, rigidity, and vaginal bleeding—though ultrasound sensitivity is only 40-50% 7
• Uterine rupture requires immediate recognition through severe abdominal pain, loss of fetal heart tones, and palpable fetal parts outside the uterus 7

Non-Obstetric Surgical Emergencies

• Appendicitis is the most common cause requiring emergency surgery in pregnancy, with atypical presentation due to anatomical displacement 4, 7
• Cholecystitis presents with right upper quadrant tenderness and positive Murphy's sign, diagnosed via ultrasound showing gallbladder wall thickening >3mm 7
• Ovarian torsion manifests as acute unilateral lower abdominal pain with a palpable adnexal mass 7

Essential Monitoring During Examination

• Maintain left lateral tilt positioning throughout the examination to optimize cardiac output and prevent maternal hypotension 4, 3
• Monitor maternal vital signs including blood pressure and heart rate, recognizing that pregnancy creates a hyperdynamic circulatory state 3
• Assess for vaginal bleeding as part of the complete examination, as this may indicate obstetric complications 7