SAN FRANCISCO – Make sure a woman who has uterine bleeding or abdominal pain in the first trimester of pregnancy gets an ultrasound the same day you see her, whether you do the ultrasound yourself, refer her to another physician for a same-day ultrasound, or send her to the emergency department, Dr. Rebecca Jackson advised.
The same-day ultrasound is essential to diagnose ectopic pregnancy early, Dr. Jackson said at a conference on women’s health sponsored by the University of California, San Francisco. The ultrasound is unlikely to show an ectopic pregnancy, but if you see an intrauterine pregnancy, "you’re done," she said.
Ectopic pregnancy occurs in 2% of pregnancies and is the leading cause of U.S. maternal deaths in the first trimester. "The key thing about ectopic pregnancy is that two-thirds of the women dying from an ectopic pregnancy had recently seen a clinician, but had an incorrect or delayed diagnosis," said Dr. Jackson, professor of obstetrics and gynecology at the university and chief of obstetrics and gynecology at San Francisco General Hospital.
Dr. Rebecca Jackson
If an ultrasound doesn’t show the location of the pregnancy, obtain serial quantitative beta-HCG levels to determine whether the pregnancy is normal or abnormal, she advised. "If it rises appropriately, it’s likely normal, but ectopics can also rise in the same way" as beta-HCG levels with intrauterine pregnancies, she said. "But if it drops or rises very little you know it’s abnormal."
Get a uterine aspiration in women with an abnormal beta-HCG level to look for placental tissue in the uterus, which indicates an intrauterine pregnancy, she said. If there’s no placental tissue in the uterus, treat for ectopic pregnancy.
There’s a shortcut in all of this to keep in mind, she added. If a woman presents with abnormal uterine bleeding or abdominal pain and she tests positive for pregnancy, ask if she desires the pregnancy. If not, you can skip the ultrasound and beta-HCG levels and go straight to the uterine aspiration, Dr. Jackson said.
These steps to diagnosing ectopic pregnancy may sound simple but in reality take ob.gyn. residents years to master. "There are so many flavors of how women present, and you combine that with their desires and their fertility desires, and it’s a really hard thing to manage," she said.
Only approximately 2% of ultrasounds done for possible ectopic pregnancy will show a gestational sac with a yolk sac or fetal pole visible outside the uterus, and thus be diagnostic, Dr. Jackson said. A normal adnexal exam does not exclude an ectopic pregnancy. An empty uterus on ultrasound and a beta-HCG level above the discriminatory zone suggests an ectopic pregnancy, and will be in 86% of cases. An ultrasound showing a complex mass and fluid in a cul-de-sac will be an ectopic pregnancy in 94% of cases. The main role of the ultrasound is to rule in an intrauterine pregnancy.
Diagnosing ectopic pregnancy early decreases the risk of rupture, which has been associated with decreased fertility and increased morbidity and mortality. "Just as an aside, rupture can occur at any level of beta-HCG and whether beta-HCG is rising or falling or plateauing, so that doesn’t help you," she said.
More treatment options are available if ectopic pregnancy is diagnosed early, including methotrexate or conservative surgical treatment, and methotrexate is more efficacious in earlier than in later ectopic pregnancy, Dr. Jackson said.
Methotrexate treatment, which is relatively new for ectopic pregnancy, "is not for everyone," she added. "It involves a lot of follow-up. Patient compliance is incredibly important. There’s still 5% who will rupture despite methotrexate treatment. And all of these things need to be explained to the patient so she can make an informed choice." Methotrexate is less effective than salpingostomy, and the efficacy of the drug decreases with increasing beta-HCG levels. Fifteen percent of patients treated with methotrexate will require a second dose.
A decrease in future intrauterine pregnancy rates in women with ectopic pregnancy is no different in those treated with methotrexate than in those treated with surgery, and the risk of a future ectopic pregnancy is increased by 10%-15% in both groups, she said.
Dr. Jackson reported having no relevant financial disclosures.
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