Sexually transmitted infections or diseases are among the most common of all infectious diseases encountered during pregnancy. Because they may be injurious to both mother and fetus, they should be aggressively sought and treated. Importantly, education, screening, treatment, and prevention are essential components of prenatal care (American Academy of Pediatrics and American College of Obstetricians and Gynecologists, 2012). Sexually transmitted infections (STIs) that affect pregnant women and potentially affect the fetus include syphilis, gonorrhea, trichomoniasis, and chlamydia, hepatitis B, human immunodeficiency virus (HIV), herpes simplex virus-1 and -2 (HSV-1, -2), and human papillomavirus (HPV) infections. Recommended therapy for most adhere to guidelines provided by the Centers for Disease Control and Prevention (CDC)(2010b). Treatment of most STIs is clearly associated with improved pregnancy outcome and prevention of perinatal mortality (Goldenberg, 2003, 2008; Ishaque, 2011; Koumans, 2012).
Despite the availability of adequate therapy for almost 70 years, syphilis remains a major issue for both mother and fetus. Syphilis rates reached an all-time low in 2000. But from 2001 through 2009 for the United States, there was a steady increase in primary and secondary syphilis rates, which then leveled in 2010 and 2011 (Centers for Disease Control and Prevention, 2013b). The primary and secondary syphilis rate among women in 2012 was 0.9 case per 100,000 persons, which is a 9-percent decrease from 2010. Congenital syphilis rates also decreased in 2012, mirroring the decline in primary and secondary syphilis rates among women since 2008. However, syphilis remains a significant global health problem, with many countries reporting high numbers of new infections (Lukehart, 2012).
Pathogenesis and Transmission
The causative agent for syphilis is Treponema pallidum. Minute abrasions on the vaginal mucosa provide an entry portal for the spirochete, and cervical eversion, hyperemia, and friability increase the transmission risk. Spirochetes replicate and then disseminate through lymphatic channels within hours to days. The incubation period averages 3 weeks—3 to 90 days—depending on host factors and inoculum size. The early stages of syphilis include primary, secondary, and early latent syphilis. These are associated with the highest spirochete loads and transmission rates of up to 30 to 50 percent. In late-stage disease, transmission rates are much lower because of smaller inoculum sizes.
The fetus acquires syphilis by several routes. Spirochetes readily cross the placenta to cause congenital infection. Because of immune incompetence prior to midpregnancy, the fetus generally does not manifest the immunological inflammatory response characteristic of clinical disease before this time (Silverstein, 1962). Although transplacental transmission is the most common route, neonatal infection may follow after contact with spirochetes through lesions at delivery or across the placental membranes. Increased maternal syphilis rates have been linked to substance abuse, especially crack cocaine; inadequate prenatal care and screening; and treatment failures and reinfection (Johnson, 2007; Lago, 2004...