eMedicine Specialties > Radiology > Obstetrics/Gynecology
Subchorionic Hemorrhage
Updated: Jun 23, 2009
Introduction
Background
Subchorionic hemorrhage (subchorionic hematoma) is the most common sonographic abnormality in the presence of a live embryo. Vaginal bleeding affects 25% of all women during the first half of pregnancy and is a common reason for first-trimester ultrasonography. Sonographic visualization of a subchorionic hematoma is important in a symptomatic woman because pregnant women with a demonstrable hematoma have a prognosis worse than women without a hematoma. However, small, asymptomatic subchorionic hematomas do not worsen the patient's prognosis.1,2,3,4,5,6,7
Sagittal endovaginal scan of the uterus in a 19-year-old woman in 20th week of gestation demonstrates a small anterior subchorionic hematoma adjacent to the lower edge of the placenta.
Sagittal endovaginal scan of the uterus demonstrates a small subchorionic hematoma (red arrow) in a 26-year-old woman in the 7th week of gestation. Also note the prominent retroplacental veins (blue arrow), which are normally in pregnancy.
Color Doppler scan in a 21-year-old woman in 33rd week of pregnancy (same patient as in Image 12 in Multimedia) demonstrates prominent retroplacental vessels mimicking a retroplacental hematoma.
In women whose sonogram shows a subchorionic hematoma, the outcome of the fetus depends on the size of the hematoma, the mother's age, and the fetus's gestational age. Rates of miscarriage increase with advancing maternal age and increasing size of hematoma. Late first- or second-trimester bleeding also worsens the prognosis.
Pathophysiology
Sagittal endovaginal scan of the uterus in a 19-year-old woman in 20th week of gestation demonstrates a small anterior subchorionic hematoma adjacent to the lower edge of the placenta.
Transverse scan demonstrates a hematoma in the same patient as in Image 2 in Multimedia.
The subchorionic hemorrhage (subchorionic hematoma) collects between the uterine wall and the chorionic membrane and may leak through the cervical canal. Later in the first trimester and early second trimester, the subchorionic hematoma may partially strip the developing placenta away from its attachment site. Therefore, the prognosis of patients with this type of hematoma is worse than the prognosis of patients with hematoma early in first trimester8 (see Images above and Images 2-3 in Multimedia).
The subchorionic hematoma often regresses, especially if it is small or moderate in size. Large hematomas, which strip at least 30-40% of placenta away from endometrium, may enlarge further, compressing the gestational sac and leading to premature rupture of membranes with consequent spontaneous abortion.
Frequency
United States
The incidence of subchorionic hemorrhage (subchorionic hematoma) is 1.3% of all pregnancies. In pregnant patients with first-trimester vaginal bleeding, the incidence increases to almost 20%. Bennett et al9 reported a spontaneous abortion rate of 9.3% in patients with first-trimester vaginal bleeding who had a live fetus and subchorionic hematoma. Overall, hematoma is associated with a 4-33% rate of miscarriage depending on the gestational age when the complication occurs.
Mortality/Morbidity
- The presence of sonographically detected subchorionic hemorrhage (subchorionic hematoma) increases the risk of miscarriage, stillbirth, abruptio placentae, and preterm labor.
- The rate of spontaneous abortion directly varies with the size of subchorionic hematoma and the mother's age. The rate of spontaneous abortion is inversely related to gestational age. The frequency of fetal demise is higher with retroplacental hematoma than with marginal subchorionic hematoma.
Race
No significant racial differences have been reported with subchorionic hemorrhage (subchorionic hematoma).
Age
Bennett et al9 reported that the spontaneous abortion rate in women aged 35 years or older is twice as high as that in younger women. After age 35 years, the first-trimester miscarriage rate reflects maternal age.
Anatomy
Before the fertilized ovum reaches the uterus, the mucous membrane of the body of the uterus increases in vascularity and thickness; it is then called the decidua. The part that covers the ovum is named the decidua capsularis. The portion that intervenes between the ovum and the uterine wall is named the decidua basalis; the placenta subsequently develops here. A small amount of bleeding may result from the implantation of the fertilized ovum in the first trimester.
The chorion consists of 2 layers: an outer layer formed by the trophoblast and an inner layer formed by the somatic mesoderm. The trophoblast undergoes rapid proliferation and forms numerous processes called chorionic villi, which invade the uterine decidua and simultaneously absorb from it nutritive materials for embryonic growth. The chorionic villi increase in size and ramify, while the mesoderm, which carries branches of the umbilical vessels, grows into them; in this way, they are vascularized. Branches of the umbilical arteries carry blood to the villi. After circulating through the capillaries of the villi, the umbilical veins return blood to the embryo.
The placenta connects the fetus to the uterine wall and is the organ by which the nutritive, respiratory, and excretory functions of the fetus are performed. The placenta is composed of fetal and maternal portions. The fetal portion consists of the villi of the chorion, and the maternal portion is formed by the decidua placentalis containing the intervillous space.
Chorionic separation from its site of endometrial attachment can lead to hemorrhaging (hematomas) in various locations in the vicinity of its original implantation. These hematomas are referred to as marginal subchorionic hematomas, in which only the placental margin is separated; retroplacental hematoma, in which bleeding is behind the placenta; and subamniotic (preplacental) hemorrhage, in which a hematoma collects anterior to the placenta and is limited by the umbilical cord.10
Subchorionic hemorrhage (hematoma) is the most common, and preplacental hematoma is the rarest. The incidence of retroplacental hematoma increases in the third trimester.
Presentation
Most patients with a small subchorionic hemorrhage (subchorionic hematoma) in the first trimester are asymptomatic.11 Common manifestations of subchorionic hematoma are idiopathic premature labor, painless vaginal bleeding, abdominal pain, and threatened abortion in the first or second trimesters.12
Symptoms of third-trimester placental abruption, observed in approximately 1% of gestations, are vaginal bleeding, a painful and tense uterus, fetal distress,13 and disseminated intravascular coagulation. Marginal abruptions are more common than retroplacental abruptions in women with mild clinical symptoms.
Preferred Examination
Ultrasonography is the imaging modality of choice for subchorionic hemorrhage (subchorionic hematoma) because it can be performed rapidly at the patient's bedside and because it has no known risk, as with radiation.14,15
Limitations of Techniques
The sensitivity of sonography is low and varies between 2% and 20%, as blood may pass vaginally and not collect in the subchorionic space. Hematomas may also appear isoechoic relative to the placenta.
Differential Diagnoses
Other Problems to Be Considered
Focal myometrial contraction (see Image 8)
Chorioamnionic separation (see Image 5)
Intra-amniotic hemorrhage (see Image 10)
Umbilical-cord hematoma
Prominent retroplacental veins (see Images 4, 11-13)
Empty gestation sac in a twin pregnancy (see Image 8)
More on Subchorionic Hemorrhage |
 Overview: Subchorionic Hemorrhage |
| Imaging: Subchorionic Hemorrhage |
| Follow-up: Subchorionic Hemorrhage |
| Multimedia: Subchorionic Hemorrhage |
| References |
| Further Reading |
| Next Page » |
References
Deutchman M, Tubay AT, Turok D. First trimester bleeding. Am Fam Physician. Jun 1 2009;79(11):985-92. [Medline].
Johns J, Hyett J, Jauniaux E. Obstetric outcome after threatened miscarriage with and without a hematoma on ultrasound. Obstet Gynecol. Sep 2003;102(3):483-7. [Medline].
Kadir R, Chi C, Bolton-Maggs P. Pregnancy and rare bleeding disorders. Haemophilia. Feb 27 2009;[Medline].
Koifman A, Levy A, Zaulan Y, Harlev A, Mazor M, Wiznitzer A, et al. The clinical significance of bleeding during the second trimester of pregnancy. Arch Gynecol Obstet. Jul 2008;278(1):47-51. [Medline].
Kurjak A, Schulman H, Zudenigo D, et al. Subchorionic hematomas in early pregnancy: clinical outcome and blood flow patterns. J Matern Fetal Med. Jan-Feb 1996;5(1):41-4. [Medline].
Pearlstone M, Baxi L. Subchorionic hematoma: a review. Obstet Gynecol Surv. Feb 1993;48(2):65-8. [Medline].
Pedersen JF, Mantoni M. Prevalence and significance of subchorionic hemorrhage in threatened abortion: a sonographic study. AJR Am J Roentgenol. Mar 1990;154(3):535-7. [Medline].
Leite J, Ross P, Rossi AC, Jeanty P. Prognosis of very large first-trimester hematomas. J Ultrasound Med. Nov 2006;25(11):1441-5. [Medline].
Bennett GL, Bromley B, Lieberman E, Benacerraf BR. Subchorionic hemorrhage in first-trimester pregnancies: prediction of pregnancy outcome with sonography. Radiology. Sep 1996;200(3):803-6. [Medline].
Nagy S, Bush M, Stone J, et al. Clinical significance of subchorionic and retroplacental hematomas detected in the first trimester of pregnancy. Obstet Gynecol. Jul 2003;102(1):94-100. [Medline].
Trop I, Levine D. Hemorrhage during pregnancy: sonography and MR imaging. AJR Am J Roentgenol. Mar 2001;176(3):607-15. [Medline].
Hodgson DT, Lotfipour S, Fox JC. Vaginal bleeding before 20 weeks gestation due to placental abruption leading to disseminated intravascular coagulation and fetal loss after appearing to satisfy criteria for routine threatened abortion: a case report and brief review of the literature. J Emerg Med. May 2007;32(4):387-92. [Medline].
Yoshida S, Kikuchi A, Sunagawa S, Takagi K, Ogiso Y, Yoda T, et al. Pregnancy complicated by diffuse chorioamniotic hemosiderosis: obstetric features and influence on respiratory diseases of the infant. J Obstet Gynaecol Res. Dec 2007;33(6):788-92. [Medline].
Abu-Yousef MM, Bleicher JJ, Williamson RA, Weiner CP. Subchorionic hemorrhage: sonographic diagnosis and clinical significance. AJR Am J Roentgenol. Oct 1987;149(4):737-40. [Medline].
Ball RH, Ade CM, Schoenborn JA, Crane JP. The clinical significance of ultransonographically detected subchorionic hemorrhages. Am J Obstet Gynecol. Mar 1996;174(3):996-1002. [Medline].
Gupta R, Sharma R, Jain T, Vashisht S. Antenatal MRI diagnosis of massive subchorionic hematoma: a case report. Fetal Diagn Ther. 2007;22(6):405-8. [Medline].
Linduska N, Dekan S, Messerschmidt A, Kasprian G, Brugger PC, Chalubinski K, et al. Placental pathologies in fetal MRI with pathohistological correlation. Placenta. Jun 2009;30(6):555-9. [Medline].
Poulose T, Richardson R, Ewings P, Fox R. Probability of early pregnancy loss in women with vaginal bleeding and a singleton live fetus at ultrasound scan. J Obstet Gynaecol. Nov 2006;26(8):782-4. [Medline].
Nyberg DA, Cyr DR, Mack LA, et al. Sonographic spectrum of placental abruption. AJR Am J Roentgenol. Jan 1987;148(1):161-4. [Medline].
Richards DS, Bennett BB. Prenatal ultrasound diagnosis of massive subchorionic thrombohematoma. Ultrasound Obstet Gynecol. May 1998;11(5):364-6. [Medline].
Dighe M, Cuevas C, Moshiri M, Dubinsky T, Dogra VS. Sonography in first trimester bleeding. J Clin Ultrasound. Jul-Aug 2008;36(6):352-66. [Medline].
Akhlaghpoor S, Tomasian A. Safety of chorionic villus sampling in the presence of asymptomatic subchorionic hematoma. Fetal Diagn Ther. 2007;22(5):394-400. [Medline].
Further Reading
ACR Appropriateness Criteria® first trimester bleeding. American College of Radiology - Medical Specialty Society. 1996 (revised 2005). 9 pages. NGC:004650
ACR Appropriateness Criteria® second and third trimester bleeding. American College of Radiology - Medical Specialty Society. 1996 (revised 2005). 2 pages. NGC:004652
Early Pregnancy Evaluation by Three-Dimensional Ultrasound
Keywords
subchorionic hemorrhage, subchorionic hematoma, vaginal bleeding, first-trimester bleeding, second-trimester bleeding, marginal subchorionic hematoma, retroplacental hematoma, subamniotic hemorrhage, preplacental hemorrhage, abruptio placentae, placenta, abruption, gestational bleeding
