Management of 39-Week Pregnant Woman with Contractions and Moderate Vaginal Bleeding
Perform pelvic ultrasound immediately before any digital vaginal examination to exclude placenta previa, vasa previa, or placental abruption, as digital examination before imaging can precipitate catastrophic hemorrhage. 1, 2
Critical First Step: Imaging Before Examination
Digital vaginal examination is absolutely contraindicated until ultrasound has definitively excluded placenta previa, low-lying placenta, and vasa previa, as examination before imaging can cause life-threatening hemorrhage in these conditions 3, 1, 2, 4
The American College of Radiology explicitly states that ultrasound must be the mainstay for diagnosis before performing digital examination in pregnant patients with vaginal bleeding 1
Even at 39 weeks with contractions suggesting labor, the risk of undiagnosed placenta previa (affecting approximately 1 in 200 pregnancies at delivery) makes blind digital examination dangerous 1
Ultrasound Evaluation Components
Transabdominal ultrasound with transvaginal ultrasound if needed should assess:
Placental location and relationship to the internal cervical os - the primary goal is to exclude placenta previa as the most common etiology for painless vaginal bleeding 3
Placental abruption - although ultrasound misses up to 50% of abruptions, identification changes management and is associated with worse perinatal outcomes 1, 2
Vasa previa using Doppler velocimetry - vessels overlying the internal cervical os can be subtle but carry risk of fetal exsanguination, and color/spectral Doppler is essential for distinguishing fetal from maternal vessels 3, 1
Uterine rupture in patients with prior cesarean delivery - looking for myometrial disruption or lower uterine segment thickness <2.5 mm 1
Why Other Options Are Incorrect
Oxytocin (Option A) is contraindicated until placental abnormalities are excluded, as augmenting contractions with undiagnosed placenta previa or abruption could worsen hemorrhage 5
Nitrazine paper test (Option B) evaluates for ruptured membranes, which is irrelevant to the immediate management priority of moderate vaginal bleeding 3
Sterile vaginal exam (Option D) is dangerous and explicitly contraindicated by multiple guidelines until imaging excludes placental causes of bleeding 3, 1, 2, 4
Clinical Pitfalls to Avoid
Never assume bleeding is from cervical dilation alone - even with contractions at term, pathologic causes must be excluded first 3, 1
Transvaginal ultrasound is safe even with placenta previa and provides superior visualization of the cervix and lower uterine segment compared to transabdominal approach alone 3, 1
Normal vital signs do not exclude significant placental pathology - placental abruption can present with normal hemodynamics initially but rapidly deteriorate 3, 4