Syphilis Rates Increasing in Peripartum Women in the United States

Pregnant woman
Pregnant woman
The rate of syphilis has been increasing in peripartum women in the United States.

The rate of syphilis has been increasing in peripartum women in the United States, according to study results recently published in Sexually Transmitted Diseases. This underscores the need for improved prenatal screening and treatment, as infection with Treponema pallidum can have adverse effects on the pregnancy and can also be vertically transmitted to the infant.

Researchers in this study examined discharge records from the National Inpatient Sample from 2010 to 2014 and found that 7518 of 18.7 million women who gave birth in US hospitals had a diagnosis of syphilis, and delivered either a live-born neonate or a still-born. Researchers then used ICD-9 codes from those delivery discharge records to compute quarterly changes per 100,000 births in frequency of syphilis diagnoses. The researchers also evaluated relative risks as a mechanism to investigate the relationship between a diagnosis of syphilis and demographic characteristics.

During the 4-year period studied, there was little change in the number of delivery hospitalizations, however the number of women discharged with a syphilis diagnosis decreased slightly between 2010 (n=1523; 95% CI, 1050-1995) and 2011 (n=1401; 95% CI, 965-1836), but increased between 2012 (n=1310; 95% CI, 1076-1544) and 2014 (n=1830; 95% CI, 1562-2098). This represented a 1.8% quarterly percentage change (P <.001) from 2012 to 2014, which was significant across all socioeconomic strata. However it was noted that the quarterly percentage was especially increased in patients receiving Medicaid (15.1% quarterly percentage increase; <.001) and white patients (35.2%; <.001).

A syphilis diagnosis was 13.02 times more likely (95% CI, 9.46-17.92) for black women and 4.53 times more likely (95% CI, 3.19-6.42) for Hispanic women compared with white women in 2014. Compared with privately insured individuals, a diagnosis of syphilis was 4.63 times more likely (95% CI, 3.38-6.33) for women receiving Medicaid and 2.84 times more likely (95% CI, 1.74-4.63) for women without insurance. Women with household incomes at the lowest tier were 5.32 times more likely (95% CI, 3.55-7.97) to be diagnosed with syphilis than those with the highest, and women from the southern part of the country were 2.42 times more likely (95% CI, 1.66-3.53) than women from the western regions.

The study investigators concluded that “[public] health and clinical action are needed to reduce the increasing rate of syphilis among pregnant females… [and c]oordinated efforts involving [women] with syphilis diagnoses, health care providers, and public health professionals can reduce the risk for mother-to-child transmission of T pallidum.”

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Aslam MV, Owusu-Edusei K, Kidd SE, Torrone EA, Dietz PM. Increasing syphilis diagnoses among females giving birth in US hospitals, 2010-2014 [published online November 19, 2018]. Sex Transm Dis. doi: 10.1097/OLQ.0000000000000945