A 19-year-old G1P0 woman is transferred from a nearby urgent care with vaginal bleeding. She reported her first positive home pregnancy test was two weeks earlier, and she has not yet been seen by an obstetrician. Her last menstrual period was approximately 14 weeks prior. She first noticed the vaginal bleeding 10 days earlier, but it resolved, and today she began spotting again. She is without fever or urinary complaints. She denies antecedent trauma or domestic violence.
Her vitals are within normal limits, her abdominal exam is benign, and her pelvic exam reveals a closed os with scant blood in the vault and no cervical motion tenderness.
Her bedside ultrasound is shown. You see clear intrauterine contents but have difficulty visualizing fetal heart rate or movements. (Image 1.) There is no significant free pelvic fluid in the cul-de-sac and the endomyometrial mantle thickness is adequate. A beta-HCG level returns at 67,000 mIU/mL.
A consultative pelvic ultrasound was performed and demonstrated heterogeneous material within the endometrial cavity that may relate to failed pregnancy. What should you do next? Does this patient warrant additional workup in the ED?
Find the diagnosis and case discussion on the next page.
Diagnosis: Molar Pregnancy
Obstetrics was consulted, and this patient was discharged and returned for a scheduled dilation and curettage (D&C). Tissue was sent for pathology and ultimately revealed a complete hydatidiform mole.
Hydatidiform moles are a gestational trophoblastic disease that result from abnormal fertilization. A complete molar pregnancy occurs when an empty egg is fertilized by two sperm, creating a diploid (46, XX or 46, XY) karyotype. The resulting tissue develops into a mass of swollen chorionic villi in grapelike structures. A small percent of these moles will become invasive or give rise to choriocarcinomas. The incidence of complete hydatidiform moles is about one in 2000 pregnancies in the United States, with increased rates in women under 20 or over 40. (Robbins Basic Pathology. Philadelphia: Elsevier Saunders; 2013, 735.)
Despite the traditionally taught clinical presentation for molar pregnancies — excessive uterine size for dates, anemia, hyperemesis, preeclampsia, and clinical hyperthyroid state — the vast majority of patients will be asymptomatic or report vaginal bleeding without other systemic manifestations. (Arch Gynecol Obstet 2000;264:33.) The classic ultrasound description of a “cluster of grapes” or a “snowstorm” is present in less than two-thirds of molar pregnancies in the first trimester. (J Ultrasound Med 1999;18:589.)
Point-of-care obstetric ultrasound is commonly used to evaluate first-trimester complications. The goal of this should be to identify a viable intrauterine pregnancy and exclude first-trimester emergencies such as ectopic pregnancies. (ACEP Emergency Ultrasound Documents; http://bit.ly/1MpP0WP.) Failure to identify a clear fetal structure or fetal heart rate should prompt referral for consultative ultrasounds and follow-up with an obstetrician. Final diagnosis of molar pregnancies is achieved by D&C with tissue pathology, after which quantitative HCG levels are trended to ensure complete evacuation of the mole.
The patient sought follow-up care in the gynecology clinic and had weekly beta-HCG levels drawn to ensure appropriate downtrending until undetectable. Thyroid studies and a chest radiograph to screen for cardiopulmonary manifestations attributable to trophoblastic embolization or thyrotoxicosis were also unremarkable. She was counseled about the importance of not becoming pregnant until her molar pregnancy resolved because a new pregnancy would complicate management. A Paragard intrauterine device was placed at the time of the D&C to guard against this.
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