Syphilis Screening in Pregnancy Is Universal, Early, and Grade A

A first prenatal visit produces a lab slip with more lines on it than most people expect, and one of them is a test for syphilis. It arrives without much of a conversation attached, tucked between blood type and a blood count, and it reads differently from the rest — an infection with a nineteenth-century reputation, ordered for someone nobody has asked a single question about risk. Somewhere around eleven at night, with the slip still folded in a bag by the door, the reasonable thought is that a clinic somewhere has quietly formed an opinion.

No opinion was formed. In May 2025 the US Preventive Services Task Force reaffirmed that syphilis screening in pregnancy is universal and early: every pregnant adolescent and adult, as early in pregnancy as possible, whether or not risk factors for syphilis are present. It carries an A, the strongest grade the Task Force issues, and behind it sits a number that has been climbing for most of a decade.

A reaffirmation is a narrower instrument than a fresh guideline, and the difference matters for how much weight the document can carry. Rather than rebuilding the evidence base from the ground up, the Task Force ran what it calls a reaffirmation deliberation process: it commissioned an evidence update focused on the benefits and harms of screening for syphilis infection in pregnancy, then looked for new findings substantial enough to justify changing a standing recommendation. The population under review was adolescents and adults who are pregnant. The accompanying evidence report, by Asher and colleagues, ran in the same issue of JAMA.

What that update turned up on the harms side was thin, and it is the honest thing to say about it. Five studies, together enrolling 51,118 participants, evaluated the harms of screening. Two studies, enrolling 130 participants between them, evaluated the harms of treatment. That is the whole of the new harms evidence. The process is built to ask whether anything recent would overturn a settled conclusion, not to re-derive that conclusion from scratch, so the reaffirmed A rests on the prior evidence base rather than on fresh proof of benefit — a distinction the grade letter itself does not show.

The conclusion was stated with high certainty: screening for syphilis infection in pregnancy has a substantial net benefit. The recommendation is early, universal screening, performed when a pregnant patient first presents to care; and if early screening was not done, screening at the first opportunity, which the statement is explicit includes presentation for delivery. That last clause is not a technicality. It is written for the pregnancies that reach a hospital with no prenatal care behind them.

The urgency is in the surveillance data the statement leads with. In 2023 there were 3882 cases of congenital syphilis in the US, including 279 congenital syphilis-related stillbirths and neonatal or infant deaths, the highest number reported in more than 30 years. Untreated infection during pregnancy can pass to the fetus, and the list of what can follow is long: premature birth, low birth weight, stillbirth, neonatal death, deformed bones, anemia, enlarged liver and spleen, jaundice, brain and nerve problems including permanent vision or hearing loss, and meningitis.

The burden is not spread evenly. Per 100,000 live births in 2023, the rate was 680.8 among Native American and Alaska Native mothers, 295.6 among Native Hawaiian and Pacific Islander mothers, 222.0 among Black mothers, 125.0 among Hispanic and Latina mothers, 82.2 among multiracial mothers, 57.3 among White mothers, and 9.3 among Asian mothers. A recommendation that applies whether or not risk factors are present is, among other things, one that does not ask a clinician to guess which patients in front of them those rates describe.

On the other side of a positive result, the statement points to the CDC's position that parenteral penicillin G is the only treatment with documented efficacy during pregnancy. The harms it names are real and bounded: false-positive or discordant results that require additional clinical evaluation, the unnecessary anxiety that travels with them, adverse effects such as an allergy to treatment medications, and the Jarisch-Herxheimer reaction, reported in 5.1% of patients receiving penicillin therapy in one study.

Two gaps are named in the document itself. The Task Force calls for studies evaluating the benefits and harms of repeat screening later in pregnancy, and for studies evaluating screening strategies that include rapid point-of-care tests. The first is the more striking, because repeat screening is already ordinary practice: the CDC and ACOG recommend repeat screening during the third trimester and at birth, and screening at 28 weeks of gestation and again at delivery in women at high risk. The standard of care in many clinics therefore runs ahead of the evidence the Task Force says it wants. That is not unusual in obstetrics, and it is not the same as the practice being wrong.

The statement is also quiet on the questions a patient holding a positive screen would reach for first. It names false-positive and discordant results as a harm without carrying a rate for either, and it does not say how often the confirmatory workup reverses an initial result. Its new treatment-harms evidence is two studies and 130 participants. And a screening recommendation is a claim about testing rather than about everything downstream of it: what was graded is the decision to test, not the reliability of the care pathway a positive result opens.

It would be easy to read a reaffirmation as committee throat-clearing, a body restating what it already said. This one is closer to the opposite. Congenital syphilis sits in the small category of severe outcomes that a cheap, decades-old treatment prevents when it is given in time, and the failure mode is almost never that medicine does not know what to do. It is that the test was not ordered, or was ordered too late, or was ordered only for the patients someone judged to be at risk. An early, universal recommendation is aimed at that failure specifically, and 3882 cases in a single year is the measure of how much of it there was to aim at.

The strength here is not that new evidence arrived — it is that the Task Force went looking for evidence that would loosen a Grade A, at a moment when congenital syphilis is at a thirty-year high, and did not find it. That combination of a settled benefit, a severe and preventable outcome, and a rising case count is what makes early universal screening the defensible default even though the fresh harms evidence underneath the reaffirmation is genuinely thin. The caveat worth naming runs opposite to the usual one: the open question is not that screening might be overused, it is that the Task Force is requesting research on repeat testing that clinics already perform, and that neither the false-positive burden nor the confirmatory pathway is quantified in the document that sets the standard. Those gaps deserve to be said out loud, and none of them weakens the case for the first test.