Sexually Transmitted Infections
Sexual intercourse is a risk factor for both pregnancy and the acquisition of a sexually transmitted infection (STI). Therefore, STIs represent a fairly common diagnosis in pregnant women. The Centers for Disease Control and Prevention (CDC) estimate that approximately 20 million cases of STIs are diagnosed annually in the United States (CDC, 2015a). The 15- to 24-year age group has the highest reported rates of chlamydia and gonorrhea infections, and these years overlap age groups with high-pregnancy rates. Since symptoms may be absent, vague, or generalized, a thorough history including a sexual history must be obtained on all pregnant women presenting for evaluation to an obstetric triage unit. Many STIs can cause fetal infections, which are contracted either in utero or during delivery as the infant passes through an infected birth canal. Pregnancy complications such as preterm labor are also associated with some STIs. Effective prenatal screening, diagnosis, and treatment of these infections will reduce most of the pregnancy complications that are attributable to STIs. The general clinical features of STIs in pregnancy are presented first, followed by more specific, detailed information regarding the most prevalent and clinically significant STIs.
The risk of acquiring an STI in pregnancy is related to the prevalence of STIs in the community. Information on the prevalence rates of STIs at the state level may be available at the state’s Department of Health (DOH) website or at the CDC website (www.cdc.gov). All treatment recommendations in this chapter are consistent with the CDC’s “Sexually Transmitted Diseases Treatment Guidelines, 2015” and are considered safe in pregnancy (CDC, 2015b).
Several of the STIs, including chlamydia and gonorrhea, frequently go unrecognized by women. The most effective key to diagnosis and treatment in the pregnant woman is to perform screening tests at the initial prenatal visit. STIs commonly screened for at the first prenatal visit include chlamydia, gonorrhea, hepatitis B, hepatitis C, HIV, and syphilis. At this time, there are no recommendations for routine prenatal screening for bacterial vaginosis (BV), trichomonas, and herpes simplex virus (HSV; CDC, 2015b). Given recent global infectious disease concerns, particularly with Zika virus, which can be sexually transmitted, immigration and travel histories of both the patient and any partners must be included in initial screening tests (Oster et al., 2016). Recommendations for Zika screening and testing are evolving. When a travel history raises concern for either the 320pregnant woman or partner, state departments of health or the CDC website can be consulted for updated testing recommendations.
INCREASES RISK OF SPONTANEOUS ABORTION
INCREASES RISK OF PRETERM LABOR
INCREASES RISK OF PERINATAL DEATH
BV, bacterial vaginosis.
Sources: Adapted from CDC (2011) and Klein and Gibbs (2004).
If a woman presents with symptoms, complaints typically will be dependent upon the specific infection. Symptoms of chlamydia and gonorrhea include vaginal discharge, irritation, vaginal spotting, cramping, discomfort, or pain. Herpetic lesions may present as itchy or painful ulcerations of the genital tract. Generalized symptoms of fever, fatigue, and nausea can be seen with a HSV primary outbreak, hepatitis B, hepatitis C, HIV, and Zika infection. Skin lesions or rashes on the body can appear in syphilis, disseminated gonorrhea, HIV, Zika, and scabies. Warty vulvar or vaginal lesions can appear with human papillomavirus (HPV).
If a pregnant woman presents complaining of vaginal spotting, cramping, or preterm contractions, STI testing must be considered since many STIs have been shown to increase the risk of miscarriage or preterm labor (Klein & Gibbs, 2004). Table 27.1 lists STIs that have been associated with increased risks for a pregnancy loss; causal relationships have not been proven. Note that treatment of these STIs in pregnancy has not been proven to lower risks of preterm delivery, as is discussed in the following text.
HISTORY AND PHYSICAL EXAMINATION
A complete sexual history includes any history of prior STIs and if there is an exposure to a new partner. The social history may reveal information about other risk factors, such as intravenous (IV) drug use or a partner with IV drug use. Women at high risk need screening for hepatitis C. A recent immigration or travel history may be helpful because infections in addition to Zika, such as lymphogranuloma venereum (LGV) and chancroid, are much more common in warmer, tropical countries.
At any obstetric triage visit, available prenatal records must be reviewed to verify what STI screening evaluations have already been performed. If the pregnant woman is late to prenatal care and has not been recently screened, screening for HIV, hepatitis B, syphilis, chlamydia, and gonorrhea are recommended. Ideally, STI screening is performed in the setting of continuous prenatal care, but if a woman is noncompliant, an obstetric triage or emergency setting visit might be the only contact point for screening.
A general physical examination is to be performed. Many of the STIs are manifested in the form of skin lesions, so a thorough examination of the skin is indicated. Table 27.2 describes common skin findings associated with STIs.
POSSIBLE FINDINGS ON SKIN EXAMINATION
Mild vulvar irritation secondary to excessive moisture exposure
Start as small red bumps around the genitalia that fill with pus, ulcerate, and become painful; takes weeks to heal. Frequently associated with enlarged firm inguinal lymph nodes that become tender (buboes)
No associated skin changes
Small beefy red nodules found in the genitalia, painless but persist; as the skin wears away, granulation tissue appears
Disseminated gonorrhea, which is rare, may be associated with septic emboli that start as reddened papules then turn into hemorrhagic lesions
Hepatitis B and C
With infections severe enough to raise liver function tests, one may see jaundice of sclera and skin
Initial infection may be associated with a rash typical of viral syndrome, meaning a diffuse macular reddened rash, which may or may not be pruritic and associated with fever, malaise, and fatigue; usually starts in head and neck
Kaposi’s sarcoma—seen in late stages, full blown AIDS, purple to red or brown, flat or raised skin growths
White- or flesh-colored growths, typically cauliflower-like, usually seen around vaginal opening, anus, cervix, or within the vagina
Small, reddened areas that at first may itch. They will blister, then ulcerate, then crust over and heal over the course of 5 to 7 days. Typically painful and usually seen near the vaginal opening or anus. May be associated with enlarged inguinal lymph nodes
Genital papules that ulcerate; lymphatics may be infected, and there may be significant vulvar swelling
Reddened areas of the skin, which are pruritic and may have small spots of blood where the lice fed and/or can be visualized in pubic hair, armpits
Mites burrow under the skin, leaving a red brown wavy line visible on the skin. These burrows are more commonly seen between fingers, the elbow crease, or the buttocks; itching is intense, especially at night.
Scattered itching reddened papules are allergic reaction to the mites and their feces
Primary—painless chancre typically in the genitals at the site of infection inoculation, classically described as punched out with rolled-up borders
Secondary—rash-disseminated small macules, reddened or brown, may be seen in palms, soles, and oral mucosa; these represent the disseminated organisms
Condyloma lata—painless gray white lesions in moist, warm sites
Vulvar and vaginal redness and irritation
Pruritic and diffuse, maculopapular rash +/− conjunctivitis
BV, bacterial vaginosis; HSV, herpes simplex virus; LGV, lymphogranuloma venereum; STI, sexually transmitted infection.
Source: Adapted from CDC (2015b).
322In cases of hepatitis, jaundice or right upper quadrant tenderness may be recognized. A vulvar examination and a vaginal speculum examination are essential. Herpetic blisters and lymphogranuloma venereum (LGV) classically present with painful vulvar lesions, while secondary syphilis can present as a nonpainful vulvar lesion. Occasionally herpetic lesions can also be identified on the cervix. Abnormal discharge is a hallmark feature of gonorrhea, BV, and trichomonas. Of note, BV is not considered a STI. It is typically identified as a creamy off-white, gray discharge that is adherent to the vaginal walls. Discharge from BV typically releases an amine or “fishy” odor when exposed to potassium hydroxide (KOH), consistent with a positive “whiff” test. Trichomonas is classically described as a frothy, gray to green discharge that may be malodorous. With trichomonas, the cervix may be irritated and covered with punctuate hemorrhages, a condition commonly referred to as a “strawberry cervix.” Gonorrheal vaginal discharge is frequently yellow and mucopurulent.
A saline wet mount microscopic examination of any vaginal discharge can be used to diagnose trichomonas and BV. Trichomonas will appear as a flagellated motile protozoan. However, microscopy is only 60% or less sensitive for trichomonas (van der Schee et al., 1999). The rapid antigen testing or direct hybridization techniques that are more sensitive and specific are becoming more widespread in their usage. BV is diagnosed when three out of four of Amstel’s criteria are identified. These criteria include an off-white vaginal discharge adherent to the vaginal walls, an amine odor or positive “whiff test,” a pH greater than 4.5, and greater than 20% clue cells per high-powered field. A clue cell is an epithelial cell whose borders are completely obscured by bacteria.
Nucleic acid amplification tests (NAATs) identify specific DNA sequences. NAATs have replaced cultures as the preferred test for chlamydia and gonorrhea in many institutions, as they are the most sensitive tests available. The Food and Drug Administration (FDA) has approved NAATs for use with urine, cervical, and urethral specimens. Herpetic lesions can be diagnosed with a viral culture or by polymerase chain reaction (PCR) testing. Herpes viral cultures have a very high false negative rate, especially with recurrent lesions, but more institutions are still using cultures over the more sensitive PCR tests (Geretti & Brown, 2005). Serologic testing for HSV is also available. Often HSV-1 and -2 serotypes will be positive from unrecognized prior infections. IgM is present only in the first several weeks of an infection, so a finding of IgM antibodies in the absence of IgG antibodies is indicative of a new infection. Blood work is necessary to test for HIV, hepatitis B and C, and syphilis antibodies. Both urine and serum testing are presently used to test for Zika virus.
CLINICAL MANAGEMENT AND FOLLOW-UP
Treatment recommendations are disease specific. Table 27.3 includes the 2015 CDC’s “Sexually Transmitted Diseases Treatment Guidelines” (CDC, 2015b), but it is specifically modified to include only those treatments that are safe in pregnancy. These treatment guidelines are also available, both online and as a phone app that can be downloaded for free under the title, “CDC 2015 STD Tx Guide.”