Continuing Education Activity

Subchorionic hemorrhage is bleeding beneath the chorion membranes that enclose the embryo in the uterus. It is thought to occur due to partial detachment of the chorion membranes from the wall of the uterus. This activity reviews the evaluation and management of subchorionic hemorrhage in pregnant patients and explains the role of the interprofessional team in managing patients with this condition. Subchorionic hemorrhage and subchorionic hematoma are the most common cause of vaginal bleeding in patients who are 10 to 20 weeks gestational age and make up about 11% of cases.

Objectives:

• Summarize the evaluation for a subchorionic hemorrhage.
• Review the complications for a subchorionic hemorrhage.
• Describe the typical imaging findings associated with subchorionic hemorrhage.
• Explain the importance of improving care coordination amongst the interprofessional team to enhance the delivery of care for pregnant patients with a subchorionic hemorrhage.

Introduction

Vaginal bleeding in the first trimester of pregnancy is a common complication, with an incidence of 16 to 25%.[1] Subchorionic hemorrhage and subchorionic hematoma are the most common cause of vaginal bleeding in patients who are 10 to 20 weeks gestational age and make up about 11% of cases.[2] Subchorionic hemorrhage is bleeding beneath the chorion membranes that enclose the embryo in the uterus. It appears to occur due to partial detachment of the chorion membranes from the wall of the uterus.[3] 

Subchorionic hematoma is another commonly used term for subchorionic hemorrhage. Most women present with light vaginal bleeding, but some are asymptomatic with incidental ultrasound findings.

Etiology

The etiology of subchorionic hematoma remains unclear.[4] Subchorionic hematomas appear to be a result of the partial separation of the chorionic membranes from the uterine wall. The presence of a uterine malformation, a history of recurrent pregnancy loss, or pelvic infections is all possible predisposing factors to a subchorionic hemorrhage.[1]

Epidemiology

Subchorionic hemorrhages occur in females of reproductive age. They are common sonographic findings in patients with vaginal bleeding in weeks 9 to 20 of pregnancy.[5] Since the first description of a subchorionic hemorrhage in 1981, the clinical significance has been a topic of debate. Some studies have shown that a subchorionic hematoma is associated with adverse outcomes in pregnancy, including hypertensive disorders, placental abruption, and preterm delivery. On the contrary, there have been studies that show there are no adverse outcomes associated with subchorionic bleeding.[6] Studies have shown that subchorionic hemorrhage is more frequent with a history of previous recurrent pregnancy loss, multiparous, and known uterine malformations.[7]

History and Physical

Patients can be asymptomatic or experience vaginal bleeding. Abdominal pain is usually absent; however, a minority of patients can experience cramping or contractions.[8] Due to risk factors described in previous studies, it is essential to obtain a detailed obstetric and gynecologic history. Up to 25% of pregnancies are complicated by first-trimester bleeding. Should a patient present with vaginal bleeding, the characteristics of the bleeding need to be documented, including quantity, if it is intermittent or constant, and if it is associated with any abdominal pain or contractions [1]. The patient’s medical history needs to be obtained, including a history of previous pregnancies and gynecologic history (history of sexually transmitted infections or pelvic inflammatory disease), and risk factors for life-threatening conditions such as ectopic pregnancy need to be identified.[9]

The abdomen should also be examined, starting by using gentle percussion in the quadrant with the least pain [10]. When a patient presents with vaginal bleeding, a speculum exam is warranted to evaluate the amount of bleeding as well as the appearance of the cervix. If there are any blood clots or products of conception on the exam, this tissue should be examined and sent for pathologic examination for further evaluation.[11] Obtaining transabdominal or transvaginal ultrasound will show that up to 22% of these patients will have sonographic evidence of intrauterine hemorrhage.[1] If the pregnancy is 10 to 12 weeks gestational age, fetal heartbeat should be checked, with 110 to 160 beats per minute being the normal range.[12]

Evaluation

All women of reproductive age presenting with abdominal pain, vaginal bleeding, or menstrual abnormalities should undergo a urine pregnancy test and determination of beta hCG. Pregnant patients who present with vaginal bleeding and or abdominal cramping should undergo an evaluation to exclude any life-threatening conditions. This differential includes ectopic pregnancy, which should be ruled out using ultrasound. Ultrasound is the imaging of choice when assessing these patients and can diagnose several pathologies that may lead to bleeding in early pregnancy.[13] 

Ultrasound findings will reveal a hypoechoic or anechoic crescent-shaped area behind the fetal membranes, which may also elevate the edge of the placenta.[14] At times, it may be challenging to identify and diagnose a subchorionic hematoma; this is due to the thin membranes and the consistency of the hematoma. If the consistency appears anechoic, it may be confused with amniotic fluid. If more isoechoic, it can be mistaken for myometrium, and when hyperechoic may be confused with placental tissue.[13] In cases where a patient presents with severe vaginal bleeding, hemoglobin/hematocrit, coagulation studies, and the type and crossmatch should be ordered. It is essential to avoid delays in the treatment of patients who are or may become hemodynamically unstable.[15]

Treatment / Management

Treatment and management should focus on specific patient complaints, gestational age, and if the patient is hemodynamically stable or unstable. Depending on the severity of the patient’s complaint (which is commonly vaginal bleeding in the setting of a subchorionic hemorrhage), treatment should be rapidly initiated.[15] Those patients who present with vaginal bleeding and are RhD negative should be given anti-D immune globulin for protection against alloimmunization in subsequent pregnancies.[16] Treatments should be tailored to the patient, the type and severity of their symptoms, as well as the size and location of the subchorionic hematoma.[17] 

Some sources suggest vaginal progesterone supplementation for patients with vaginal bleeding in the first trimester; however, this has not been shown to increase live birth rates, and its routine use is not recommended.[18] Researchers have noted fewer spontaneous abortions and a higher rate of term pregnancy in patients undergoing bed rest; however, these studies have not been significant enough to change current recommendations and guidelines.[2] In a mother that is stable with a stable fetus, with no evidence of a large volume of blood loss, conservative management with follow-up ultrasound evaluation is adequate.[19]

Differential Diagnosis

The differential diagnosis for a female patient of reproductive age presenting with abdominal pain or vaginal bleeding is vast. The initial goal is to identify patients with a serious or life-threatening disease or condition for their symptoms. If the patient is known or found to be pregnant, intrauterine pregnancy should be confirmed via ultrasound to rule out a life-threatening ectopic pregnancy. Other common differential diagnoses include early pregnant loss (miscarriage or spontaneous abortion), threatened abortion, implantation bleeding, placental abruption, placenta previa, vasa previa, gestational trophoblastic disease, uterine rupture, ovarian torsion, a tubo-ovarian abscess.

Prognosis

For women with a subchorionic hematoma that is sonographically identified, the fetal outcome is dependent on the size of the hematoma, maternal age, and gestational age.[17] Subchorionic hematoma is associated with an increased risk of pregnancy loss if it accounts for 25% or more of the volume of the gestational sac. There is also an increased risk of an adverse outcome when the location of the hematoma is retroplacental versus marginal.[14] The earlier in pregnancy, a subchorionic hematoma is identified, the higher the rate of subsequent pregnancy failure.[20]

Subchorionic hematoma increases the risk of spontaneous abortion, while premature delivery rate and delivery mode are not affected if pregnant women can continue the pregnancy.[21] First-trimester subchorionic hematoma is not associated with adverse pregnancy outcomes at more than 20 weeks gestation.[22] The hospitalization period and the ratio of pregnancy loss increase when the ratio of surrounding hematoma to gestational sac increases when accompanied by nonspecific pelvic pain.[23]

Complications

Pregnant women with subchorionic hematoma (SCH) are associated with an increased risk of early pregnancy loss.[4] Women with subchorionic hematoma are at a fivefold or more increased risk of developing placental abruption. Patients with subchorionic hematoma also at risk for other complications, including preterm labor, premature rupture of membranes, early and late pregnancy loss.[14] 

Subchorionic hematoma diagnosed at the beginning of pregnancy is a risk factor of pregnancy-induced hypertension in the third trimester.[7] SCH diagnosed in early pregnancy does not influence the method of delivery and does not increase the risk of adverse pregnancy outcomes.[7]

Deterrence and Patient Education

Subchorionic hematoma, although not considered normal in pregnancy, is not an unusual occurrence. It is important to let patients know that this does not mean they will lose the pregnancy. With close monitoring, the majority of these cases go on to deliver healthy babies. Subchorionic bleeding does not mean that the pregnancy is in imminent danger; however, it is important to follow up with the physician. Patients need to know the necessary precautions and when to be concerned or return to the hospital. These precautions include but are not limited to vaginal bleeding or spotting, abdominal pain.

Enhancing Healthcare Team Outcomes

Because of the many causes of bleeding in the first trimester, when a subchorionic hematoma would normally present, this must be managed by an interprofessional healthcare team that encourages close follow-up with the patient. This team can include primary care, emergency providers, obstetricians, midwives, and specialty trained nurses in obstetrics. In cases where patients present with heavy vaginal bleeding and pelvic cramping, it is important to stabilize the patient if needed, followed by evaluating the pregnancy. In most cases, a subchorionic hematoma is managed by an obstetrician and gynecologist, who follows up with serial ultrasounds and monitoring patient symptoms.