Reproductive · Spontaneous Abortion
The facts most likely to be tested
Incomplete abortion presents with vaginal bleeding and cramping accompanied by the passage of some, but not all, products of conception.
Physical examination reveals a dilated cervical os with retained tissue visible or palpable in the cervical canal.
Transvaginal ultrasound demonstrates a thickened, heterogeneous endometrial stripe often containing echogenic material within the uterine cavity.
Hemodynamically stable patients are managed with expectant management, medical evacuation using misoprostol, or surgical evacuation via suction curettage.
Surgical evacuation via suction curettage is the mandatory treatment for patients presenting with hemodynamic instability, sepsis, or severe hemorrhage.
Patients who are Rh-negative require the administration of anti-D immune globulin (RhoGAM) to prevent alloimmunization.
Incomplete abortion is distinguished from inevitable abortion by the presence of retained products of conception rather than an empty uterus or intact gestational sac.
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A 28-year-old G2P1 woman at 10 weeks gestation presents to the emergency department with heavy vaginal bleeding and lower abdominal pain. She reports passing 'fleshy tissue' at home earlier this morning. On physical exam, her blood pressure is 110/70 mmHg and pulse is 88/min. Pelvic examination reveals a dilated cervical os with clots and tissue protruding through the canal. Transvaginal ultrasound shows a thickened, heterogeneous endometrial stripe measuring 22 mm with no identifiable fetal cardiac activity.
What is the most appropriate next step in management?
Surgical evacuation (suction curettage) or medical management with misoprostol
The patient's presentation of a dilated cervix and retained tissue on ultrasound confirms an incomplete abortion, which requires uterine evacuation to prevent hemorrhage and infection.
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Etiology / Epidemiology
Occurs when partial expulsion of products of conception (POC) happens before 20 weeks. Advanced maternal age and prior spontaneous abortion are primary risk factors.
Clinical Manifestations
Presents with heavy vaginal bleeding, cramping, and a dilated cervical os. Retained POC on ultrasound is the pathognomonic finding.
Diagnosis
Transvaginal ultrasound is the gold standard. Look for an endometrial stripe >15 mm with heterogeneous contents.
Treatment
Misoprostol is the first-line medical management. Do not use if hemodynamically unstable; perform Dilation and Curettage (D&C) instead.
Prognosis
Most recover fully after evacuation. Infection (endometritis) and hemorrhage are the primary complications requiring urgent intervention.
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Epidemiology & Etiology
Incomplete abortion is a common complication of early pregnancy, typically occurring in the first trimester. Major risk factors include chromosomal abnormalities, maternal endocrine disorders, and uterine anatomical anomalies. It is distinguished from other pregnancy losses by the presence of retained tissue within the uterus.
Pertinent Anatomy
The cervical os remains open, allowing for the passage of blood and tissue. The uterus is often smaller than expected for gestational age but remains enlarged due to the presence of retained POC.
Pathophysiology
The process begins with the separation of the placenta from the uterine wall, leading to uterine contractions. While some tissue is expelled, the cervix fails to close, and the uterus cannot contract effectively to achieve hemostasis. This results in persistent myometrial atony and ongoing hemorrhage.
Clinical Manifestations
Patients report heavy vaginal bleeding and persistent lower abdominal pain. Physical exam reveals a dilated cervical os with visible tissue at the os or in the vaginal canal. Signs of hemodynamic instability such as tachycardia or hypotension indicate severe blood loss requiring immediate resuscitation.
Diagnosis
Transvaginal ultrasound is the diagnostic modality of choice. Findings include a thickened, irregular endometrial stripe >15 mm containing echogenic material. A positive beta-hCG confirms pregnancy, but serial levels are less useful than imaging for acute management.
Treatment
Stable patients are managed with Misoprostol to induce complete evacuation. Surgical management via Dilation and Curettage (D&C) is indicated for patients with hemodynamic instability, signs of infection, or failure of medical management. Administer Rho(D) immune globulin if the patient is Rh-negative.
Prognosis
Prognosis is excellent with prompt evacuation. Endometritis is the most common infectious complication, presenting with fever and foul-smelling discharge. Monitor for Asherman syndrome following aggressive curettage.
Differential Diagnosis
Threatened abortion: closed cervical os
Inevitable abortion: no passage of tissue yet
Complete abortion: empty uterus on ultrasound
Ectopic pregnancy: adnexal mass on ultrasound
Molar pregnancy: snowstorm appearance on ultrasound