Syphilis Infection: Screening -- Pregnant Women


General

Grade: A The USPSTF recommends the service. There is high certainty that the net benefit is substantial. Offer or provide this service.

Specific Recommendations

The USPSTF recommends early screening for syphilis infection in all pregnant women.

Frequency of Service

All pregnant women should be tested for syphilis as early as possible when they first present to care. If a woman has not received prenatal care prior to delivery, she should be tested at the time she presents for delivery. In most cases of congenital syphilis, pregnant women received prenatal care but were not screened and treated for syphilis early enough during the pregnancy to prevent transmission to the fetus.

Risk Factor Information

No information available.


Clinical

Patient Population Under Consideration

This recommendation applies to all pregnant women.

 

Screening Intervals

All pregnant women should be tested for syphilis as early as possible when they first present to care. If a woman has not received prenatal care prior to delivery, she should be tested at the time she presents for delivery. In most cases of congenital syphilis, pregnant women received prenatal care but were not screened and treated for syphilis early enough during the pregnancy to prevent transmission to the fetus.

 

The USPSTF found no new studies that examined the effectiveness of repeated testing for syphilis during pregnancy. The Centers for Disease Control and Prevention (CDC)5 and joint guidelines from the American Academy of Pediatrics (AAP) and the American College of Obstetricians and Gynecologists (ACOG)6 endorse repeat screening. Specifically, these groups recommend that women at high risk for syphilis be rescreened early in the third trimester (at approximately 28 weeks of gestation) and again at delivery. Women at high risk for syphilis infection include those living in communities or geographic areas with higher prevalence of syphilis, those living with HIV, and those with a history of incarceration or commercial sex work.7 AAP and ACOG also recommend repeat screening after exposure to an infected partner.6 Clinicians should be aware of the prevalence of syphilis infection in the communities they serve.7 Most states mandate screening for syphilis in all pregnant women at the first prenatal visit, and some mandate screening at the time of delivery.8

 

Screening Tests

Syphilis infection is caused by the Treponema pallidum bacteria. Current screening tests for syphilis rely on detection of antibodies to the infection rather than direct detection of the bacteria. Screening for syphilis infection is a 2-step process. Traditionally, screening involved an initial “nontreponemal” antibody test (ie, Venereal Disease Research Laboratory test or rapid plasma reagin [RPR] test) to detect biomarkers released from damage caused by syphilis infection, followed by a confirmatory “treponemal” antibody detection test (ie, fluorescent treponemal antibody absorption or T pallidum particle agglutination test). Because nontreponemal tests are complex, a reverse sequence screening algorithm has been developed in which an automated treponemal test (such as an enzyme-linked, chemiluminescence, or multiplex flow immunoassay) is performed first, followed by a nontreponemal test. If the test results of the reverse sequence algorithm are discordant, a second treponemal test (preferably using a different treponemal antibody) is performed. The USPSTF found no studies comparing the false-positive rate of the traditional screening algorithm with that of the reverse sequence screening algorithm among pregnant women. The CDC has provided more detailed guidance on testing for and treatment of sexually transmitted diseases, including syphilis.9

 

Treatment

In 2015, the CDC recommended parenteral benzathine penicillin G for the treatment of syphilis in pregnant women.5 Evidence on the efficacy or safety of alternative antibiotic medications for pregnant women and the fetus is very limited; therefore, women who report a penicillin allergy should be evaluated and, if found allergic, desensitized and treated with penicillin. Because the CDC updates its recommendations regularly, clinicians are encouraged to consult the CDC website for the most up-to-date information.9

 

Additional Approaches to Prevention

Trends in congenital syphilis incidence rates are closely related to trends in primary and secondary syphilis infection rates among all women. Screening for syphilis in nonpregnant populations is an important public health approach to preventing the sexual transmission of syphilis and subsequent vertical transmission of congenital syphilis. The USPSTF recommends screening for syphilis in nonpregnant adolescents and adults at increased risk for infection.10

 

Useful Resources

The USPSTF has made recommendations on screening for other sexually transmitted infections, including chlamydia and gonorrhea,11 hepatitis B virus,12 genital herpes,13 and HIV.14 National-, state-, and county-level data on syphilis infection rates are also available from the CDC.2


Rationale

Importance

Syphilis is an infection that is primarily sexually transmitted. Untreated syphilis infection in pregnant women can also be transmitted to the fetus (congenital syphilis) at any time during pregnancy or at birth. Congenital syphilis is associated with stillbirth, neonatal death, and significant morbidity in infants (eg, bone deformities and neurologic impairment).1 After a steady decline from 2008 to 2012, cases of congenital syphilis markedly increased from 2012 to 2016, from 8.4 to 15.7 cases per 100,000 live births (an increase of 87%).2 At the same time, national rates of syphilis increased among women of reproductive age.

 

Reaffirmation

In 2009, the USPSTF reviewed the evidence on screening for syphilis infection in pregnant women and issued an A recommendation.3 The USPSTF has decided to use a reaffirmation deliberation process to update this recommendation. The USPSTF uses the reaffirmation process for well-established, evidence-based standards of practice in current primary care practice for which only a very high level of evidence would justify a change in the grade of the recommendation.4 In its deliberation of the evidence, the USPSTF considers whether the new evidence is of sufficient strength and quality to change its previous conclusions about the evidence.

 

Detection

The USPSTF found adequate evidence that screening tests can accurately detect syphilis infection in pregnant women.

 

Benefits of Detection and Early Treatment

The USPSTF found convincing evidence that early universal screening for syphilis infection in pregnant women reduces the incidence of congenital syphilis and the adverse outcomes of pregnancy associated with maternal infection.

 

Harms of Detection and Early Treatment

Screening for syphilis infection in pregnant women may result in potential harms, including false-positive results that require clinical evaluation, anxiety, and harms of treatment with antibiotic medications. However, the USPSTF concluded that these harms of screening are no greater than small.

 

USPSTF Assessment

Using a reaffirmation process,4 the USPSTF concludes with high certainty that the net benefit of screening for syphilis infection in pregnant women is substantial.


Others

Other Considerations: Research Needs and Gaps Although the benefits of screening for syphilis infection in pregnant women to prevent congenital syphilis are well established, additional studies on the use of different screening algorithms in pregnant women, as well as studies to help identify optimal rescreening intervals and populations to rescreen during pregnancy, could help inform implementation of screening programs. Studies on treatment options besides penicillin could also be helpful.   Reaffirmation of Previous USPSTF Recommendation This recommendation is a reaffirmation of the USPSTF 2009 recommendation statement.3 In 2009, the USPSTF reviewed the evidence on screening for syphilis infection in pregnant women and found that the benefits of screening substantially outweighed the harms.22 For the current recommendation, the USPSTF commissioned a targeted review16 to look for substantial new evidence on the benefits and harms of screening and determined that the net benefit of screening for syphilis infection in pregnant women continues to be well established. The USPSTF found no new substantial evidence that could change its recommendation and, therefore, reaffirms its recommendation to screen for syphilis infection in all pregnant women. Recommendations of Others This recommendation statement is consistent with those of other professional and public health organizations. The CDC recommends screening for syphilis infection in all pregnant women at their first prenatal visit.5 Joint guidelines from AAP and ACOG recommend screening for syphilis infection in pregnant women as early as possible in pregnancy.6 The CDC, AAP, and ACOG also recommend repeat screening at 28 weeks of gestation and again at delivery in high-risk women. Women at high risk for syphilis infection include those living in high-prevalence communities, those living with HIV, and those with a history of incarceration or commercial sex work.10 AAP and ACOG also recommend repeat screening after exposure to an infected partner.6 The American Academy of Family Physicians recommends screening for syphilis infection in all pregnant women.29


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