Sexual and reproductive health

Over a million pregnant women infected with syphilis worldwide

Can the Perinatal Information System in Peru be used to measure the proportion of adverse birth outcomes attributable to maternal syphilis infection?

August 2014

Syphilis still affects large numbers of pregnant women worldwide, causing serious health problems and even death to their babies, yet this infection could be prevented by early testing and treatment, according to a study by international researchers published in PLOS Medicine (26 February 2013).

Accelerating dual elimination of Mother-To-Child Transmission of Syphilis and HIV through use of new diagnostic tools.

Syphilis testing in pregnancy

Finger stick testing for syphilis in Mozambique

Not all women are tested for syphilis in pregnancy. In order to eliminate mother-to-child transmission of syphilis, countries should test at least 95% of pregnant women for syphilis at first antenatal care visit.

Estimate show that in 2008, 1.4 million pregnant women around the world were infected with syphilis, 80% of whom had attended antenatal care services.

The researchers reached this figure by using information on the number of syphilis infections from 97 countries and on antenatal clinic attendance from 147 countries and then inputted this information into a model.

In consultation with experts, the authors used a realistic scenario to estimate the percentage of pregnant women tested for syphilis and adequately treated, ranging from 30% for Africa and the Mediterranean region to 70% for Europe. Based on this scenario, the authors estimate that in 2008, syphilis infections in pregnant women caused approximately 520,000 harmful outcomes, including 215,000 stillbirths, 90,000 neonatal (baby) deaths, 65,000 preterm or low birth-weight babies, and 150,000 babies with congenital infections.

Syphilis continues to be an important cause of adverse outcomes of pregnancy, including substantial numbers of perinatal deaths and disabilities

The authors estimate that in 2008, testing and treating pregnant women for syphilis prevented a quarter of such harmful outcomes but worryingly, the authors found that about two-thirds of these harmful effects occurred in women who had attended antenatal care but were not treated or tested for syphilis. They continue: “Countries also need to ensure that quality-assured syphilis testing is available in all antenatal clinic settings, now possible even in remote care settings with the introduction of rapid point-of-care diagnostics.”

The authors add: “In addition, efforts are needed to ensure universal access to early antenatal care, as well as improved quality of antenatal care so that all pregnant women receive an essential package of services that includes routine and early access to point-of-care testing and adequate treatment for syphilis if seropositive.”

Tool to estimate burden of maternal syphilis and adverse outcomes

A health worker reports data on sheets in a health center, Sri Lanka. Photo credit: World Bank/Simone D. McCourtie
World Bank/Simone D. McCourtie

This tool is intended for use by countries to estimate the burden of syphilis in pregnancy and associated adverse outcomes using readily available data. This simple tool can be used at a national or a subnational level. The methodologies used in the tools have been reviewed and approved by the Child Health Epidemiology Research Group and used for the recent global estimates. An accompanying set of instructions is available to guide the user through the estimation process.