Screen High-Risk Women Three Times for Syphilis in Pregnancy; at Initial Visit, 28 Weeks, and Delivery
January 8, 2003
Clinicians with high-risk patients in areas with a high prevalence of syphilis should screen women three times during pregnancy to decrease the risk of congenital syphilis, Dr. Virginia Caine recommended recently at the annual meeting of District V of the American College of Obstetricians and Gynecologists. "They should do the first screen at the women's initial prenatal visit," she said, "but then they should do two more in the third trimester, one at 28 weeks' gestation and then another one at the time of delivery," said Caine, who is with the division of infectious diseases at Indiana University-Indianapolis.Adapted from:
Most physicians are not aware of the need for a third screen. "They generally know they should do a screen in the third trimester, but they generally do one at delivery instead of doing it at 28 weeks," Caine noted in an interview. "Or they do it at 28 weeks but are not aware that they should do another one at delivery. Both are necessary."
Pregnant women with untreated syphilis run a 22 percent risk of delivering a stillborn; a 33 percent risk of having an infected infant; and a 33 percent chance of delivering an uninfected baby. Neonatal death occurs in 12 percent of babies born to infected, untreated mothers.
CDC's new treatment guidelines for STDs recommend benzathine penicillin G 2.4 million U IM in a single dose for primary, secondary or early latent syphilis. Some experts recommend a second dose of benzathine 2.4 million U IM for primary, secondary and early latent syphilis one week after the first dose.
Late latent syphilis and tertiary syphilis, according to CDC, should be treated with three doses of 2.4 million U IM of benzathine at one-week intervals.
Women treated for syphilis in the second half of pregnancy are "at risk for premature labor and/or fetal distress if the therapy precipitates the Jarisch-Herxheimer reaction," Caine said. The Jarisch-Herxheimer reaction, which occurs within two hours of the dose, can cause fever, chills, myalgia, headache, rapid heart and respiratory rate, and vasodilation with hypotension. The patient's temperature usually peaks about seven hours after the dose, and symptoms subside within 12 to 24 hours. Bed rest and aspirin are the recommended treatment. The Jarisch-Herxheimer reaction results from the killing of spirochetes in the blood and the release of endotoxins into the tissues, according to Caine.
Caine said that adequate treatment of an infected pregnant woman before 16 weeks' gestation should prevent transmitting the infection to the infant. However, regardless of when the mother's infection is first detected and treated, doctors should consider a sonographic evaluation of the fetus in the second half of pregnancy to check for hepatomegaly, ascites, and hydrops, all of which could indicate a greater risk of fetal infection.
OB GYN News
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This article was provided by CDC National Prevention Information Network. It is a part of the publication CDC HIV/Hepatitis/STD/TB Prevention News Update.