Subchorionic hematomas are not an infrequent finding during the first trimester. They are usually small and not thought to substantially increase the risk of a nonviable pregnancy. Large (two-thirds or more of the gestational sac circumference) subchorionic hematomas may be associated with an increased risk of nonviable pregnancy [30]. Ectopic pregnancy Whenever an IUP is not identified in a patient with a positive pregnancy test, extrauterine locations for the pregnancy should be carefully evaluated [31,32]. This involves identification of the ovaries and corpus luteum along with a careful search for any extraovarian mass that is not a paraovarian cyst or pedunculated fibroid because the vast majority of ectopic pregnancies are in the fallopian tube. Ectopic pregnancies are located ipsilateral to the corpus luteum in 70% to 80% of cases [33,34] and it is important to distinguish between the First Trimester Vaginal Bleeding Although visualization of an extrauterine gestational sac with a live embryo is 100% specific for an ectopic pregnancy, this situation is uncommon [39]. More common, though slightly less specific, is an extrauterine mass with a fluid center and hyperechoic periphery, which has been termed a tubal ring [40,41]. Additionally, the ectopic pregnancy may appear as a nonspecific heterogeneous mass with no identifiable gestational sac within it. This latter appearance has been reported as the most common sonographic finding of a tubal pregnancy [39]. Even with such a nonspecific-appearing mass, tubal pregnancy is likely when the mass is outside the ovary (with no other obvious cause, such as a pedunculated fibroid or paraovarian cyst) in a patient with a positive serum hCG and no sonographic evidence of an IUP [41]. Given the potential for inappropriate management with methotrexate or surgical intervention, the diagnosis of ectopic pregnancy should generally be based on positive findings and not solely on the absence of an IUP.
First Trimester Vaginal Bleeding. Subchorionic hematomas are not an infrequent finding during the first trimester. They are usually small and not thought to substantially increase the risk of a nonviable pregnancy. Large (two-thirds or more of the gestational sac circumference) subchorionic hematomas may be associated with an increased risk of nonviable pregnancy [30]. Ectopic pregnancy Whenever an IUP is not identified in a patient with a positive pregnancy test, extrauterine locations for the pregnancy should be carefully evaluated [31,32]. This involves identification of the ovaries and corpus luteum along with a careful search for any extraovarian mass that is not a paraovarian cyst or pedunculated fibroid because the vast majority of ectopic pregnancies are in the fallopian tube. Ectopic pregnancies are located ipsilateral to the corpus luteum in 70% to 80% of cases [33,34] and it is important to distinguish between the First Trimester Vaginal Bleeding Although visualization of an extrauterine gestational sac with a live embryo is 100% specific for an ectopic pregnancy, this situation is uncommon [39]. More common, though slightly less specific, is an extrauterine mass with a fluid center and hyperechoic periphery, which has been termed a tubal ring [40,41]. Additionally, the ectopic pregnancy may appear as a nonspecific heterogeneous mass with no identifiable gestational sac within it. This latter appearance has been reported as the most common sonographic finding of a tubal pregnancy [39]. Even with such a nonspecific-appearing mass, tubal pregnancy is likely when the mass is outside the ovary (with no other obvious cause, such as a pedunculated fibroid or paraovarian cyst) in a patient with a positive serum hCG and no sonographic evidence of an IUP [41]. Given the potential for inappropriate management with methotrexate or surgical intervention, the diagnosis of ectopic pregnancy should generally be based on positive findings and not solely on the absence of an IUP.