Providing medical care, prenatal or otherwise, to a pregnant woman with substance use disorder is a unique opportunity to address immediate medical concerns, and also to attend to health issues that may have gone unnoticed or ignored during active use. Many people, and particularly pregnant women, with substance use disorder are hesitant to seek routine medical care. In fact, assessments of utilization of health care repeatedly demonstrate that people with substance misuse, “heavy” alcohol use, and/or intravenous substance use receive less preventative and routine health care for minor ailments than any other demographic , despite having similar rates of need of treatment for chronic medical and mental health conditions as nonsubstance using people .
General Medical History
Beginning with the initial prenatal visit, taking a thorough medical history should include all the categories of assessment regularly employed for all patients, including current concerns, allergies, medications, review of systems, past medical history, past surgical history, family and social history . The first interview should, naturally, also include a thorough obstetrical and gynecological history. Given the time and attention, this type of history gathering can make this as an excellent opportunity for rapport building prior to more in-depth questions regarding substance use.
Substance Use History
In addition to these usual assessments, a thorough substance use history should be obtained with compassion and acceptance, paying special attention to history of withdrawal symptoms and/or prior hospitalizations or treatments needed for detoxification complications. As described in earlier chapters, many pregnant women have a history of polysubstance use, and careful attention should be employed to assess for need for level of care if detoxification is necessary. For example, women with use of opioids as well as benzodiazepines and/or alcohol may have history of complicated withdrawal. Knowing this information will help the prenatal provider assess for necessary referral for residential or inpatient detoxification.
Keeping in mind the significant number of women with history of emotional, physical, and/or sexual trauma who develop substance use disorders, providing a comprehensive prenatal physical exam should be completed with the patient’s safety and comfort in mind. This should include a discussion of what body parts need to be examined prior to physically contacting the patient, providing the option of patient moving or adjusting clothing, or undressing in stages, instead of completely undressing and wearing a gown, and agreeing upon a signal the patient may give, either verbal or nonverbal, should they need to signal distress during the exam. Allowing patients to ask questions about the exam prior to initiating physical contact is another way to help empower patients to feel in control of their body and their medical care .
Women with opioid use disorder often have physical findings that should be noted. Poor dentition is common in people with substance use disorders, and should not be ignored in pregnancy. Noting damaged or missing teeth, caries, or gingival disease should prompt a referral for dental care . Cardiac murmurs or rubs may be present, as well as pulmonary findings such as wheezes, crackles, or increased expiratory phase. Cutaneous signs of injection use (intravenous, subcutaneous, or intramuscular) might include a range of findings, from mild bruising and scarring to necrosis of skin and soft tissue. Edema of hands or extremities may be noted due to vascular or lymphatic injury from injection. If the patient consents, a breast exam may reveal use of veins of the breast for injection use. Noting hepatomegaly or hepatic tenderness on exam would prompt further evaluation. The provider should also note any signs concerning for interpersonal violence, such as bruising, abrasions, ligature marks, or genital or anal injuries , and document such injuries in accordance with recommendations from the National Institute of Justice. Even if the patient does not wish to file a police report about any abuse she is experiencing at that point in time, a clear and comprehensive medical record, including photographs of injuries if appropriate and patient consents, can provide helpful evidence should the abuse ever be reported or prosecuted .
One of the most commonly recognized and variable health consequences for women with opioid use disorder in pregnancy is infection. Risk for infection comes not only from the substance use itself, especially injection use, but also from sexual practices or partners with high prevalence of infectious disease and/or limited access to harm reduction programs including syringe exchange . People with substance use disorders also often have reduced immune function, nutritional deficiencies, and health complications from chronic stress and inadequate sleep, particularly salient for people also experiencing intermittent or chronic homelessness (Figure 7.1).
|Soft tissue and bone infection|
Sexually Transmitted Disease
Providing care to pregnant women with opiate use disorder provides the opportunity for a complete evaluation of and, if necessary, treatment for sexually transmitted illness. Some women with opiate use disorder are at increased risk for STI, especially if they have been involved in work in the sex trade. Women with substance use disorder in general are at higher risk than the general population for sexual assault, coerced sex, sex with multiple partners, and other risky sexual behaviors. Women with injection drug use in particular have been shown to have lower rates of use of condoms, higher rates of multiple sexual partners, and higher rates of undetected or untreated STIs . Providing testing and treatment for STIs, screening for cervical cancer, and potentially providing vaccination for HPV (human papilloma virus) after delivery can have long-reaching health impact for this patient population, as well as opportunity to increase sexual health literacy and self-efficacy .
Hepatitis B (HBV) is estimated to impact approximately 0.7–0.9 percent of pregnant women in the United States, with more than 25,000 infants at risk per year of vertical transmission leading to chronic HBV infection [15, 16]. Vertical transmission from mother to child remains a major source of perpetuation of chronic HBV worldwide. Given this high risk for vertical transmission, as well as effective available treatments to reduce risk of transmission, it has been recommended for several years that all pregnant women be screened for Hepatitis B in pregnancy with a test of hepatitis B surface antigen (HBsAg). Testing for HBV surface antibody alone does not rule chronic infection in or out, and thus HBsAg testing is the preferred assessment .
Relevant to the population of pregnant women with opiate use disorder, women who are at risk for Hepatitis B infection (>1 sexual partner during last 6 months, evaluated or treated for a sexually transmitted disease, history of or current injection substance use, or a sexual partner with known positive HBsAg) and do not have demonstrated immunity to HBV should be offered immunization.
For many women, chronic HBV may be asymptomatic, and thus screening in pregnancy may lead to their initial diagnosis of HBV. For these women, antenatal counseling is crucial, as there are approved treatments for both mother and neonate to help prevent vertical transmission.
Given that exposure to blood and body fluids is one major risk for transmission of HBV, there has been some debate about the safety of invasive antenatal testing (chorionic villous sampling or amniocentesis). Current guidelines recommend that for women with an indication for genetic testing with an invasive procedure, appropriate counseling for women with HBV RNA viral load >7 log 10 copies/mL should include a possible increased risk for maternal–fetal transmission. At time of delivery, invasive labor procedures such as internal monitors or operative vaginal delivery should not be prevented if indicated. This increased risk of transmission by exposure through either invasive prenatal or intranatal procedures is not thought to be greater than the protection conferred by perinatal infection prevention with both passive and active immunization given to exposed infants. Similarly, planned cesarean section is not recommended for the sole indication of attempt to reduce maternal–fetal transmission of HBV .
The significant advances in reducing maternal–fetal transmission of HBV have traditionally centered on providing passive and active immunity to HBV to the exposed infant within 12 hours from birth. By providing the combination of HBV immunoglobulin and HBV vaccine, it has been shown that durable protection from chronic HBV can be provided to 85–95 percent of exposed infants. Current recommendations are to provide this combination of passive and active immunity to all HBV exposed infants, including infants whose mother’s HBsAg status is unknown. For infants who receive prophylaxis, breastfeeding is recommended.
As more recent evidence has demonstrated benefit for antenatal viremia reduction in prevention of vertical transmission of HBV, antiviral therapy has been increasingly offered to appropriate pregnant candidates. Since maternal viral load has been shown to be a direct indicator of immunoprophylaxis failure, checking HBV RNA viral load at time of initial diagnosis and in the third trimester is now recommended. In pregnant women with HBV viral load greater than 6–8 log 10 copies/mL, HBV antiviral therapy should be considered for the purpose of decreasing maternal viral load and thus reducing risk of vertical transmission. Referral to maternal–fetal medicine, hepatology, or infectious disease practitioners with experience treating HBV in pregnancy is appropriate at time of diagnosis, or in the third trimester for consideration of antiviral therapy, and for continued coordinated care and surveillance for women after delivery (Figure 7.2).
Figure 7.2 Hepatitis B laboratory evaluation
As the opioid epidemic has reached critical importance in the public health, and more broadly, societal eye, so too has the increase in rates of Hepatitis C (HCV). Historically, screening tests for Hepatitis C have been offered to patients with identifiable risk factors, such as known injection substance use. Other identified risk factors for HCV that have been broadly accepted are blood transfusion or products, organ transplantation prior to 1992, hemodialysis, or HIV coinfection. Testing women with these identifiable risks in pregnancy is recommended by both the Centers for Disease Control and Prevention and the American College of Obstetrics and Gynecologists, but universal screening in pregnancy has not been considered a cost-effective strategy . However, as newer research has demonstrated, using a policy of testing for HCV in only women with such identifiable risk factors has significant limitations, such that between 28 and 40 percent of pregnant women with HCV could go unidentified (Figure 7.3) [19, 20].
Currently accepted risk factors:
If a woman with opioid use disorder is offered testing, and does in fact test positive for HCV, many laboratories will now reflexively test for HCV RNA viral load as well as genotype. Testing hepatic function studies at the same time would also be recommended. If this type of reflexive laboratory testing is not in place, a positive HCV antibody would then necessitate further testing as mentioned above. While no antiviral therapies have been yet approved for use in the treatment of HCV in pregnancy or breastfeeding, this should not discourage providers from testing for HCV in the antenatal period. Given that vertical transmission of HCV is estimated at 2–10 percent , vertical transmission remains one of the most common routes of infection, and is comparable in risk to injection substance use. Providing appropriate antenatal guidance for the pregnant woman regarding vertical transmission rates and neonatal follow up should be included as part of the care for our pregnant patients with opiate use disorder and HCV. Patients should also be educated that unless they have HIV co-infection, HCV is not a contraindication to breastfeeding. Also of note, pregnancy is not a contraindication to Hepatitis B vaccination, and should be offered to any pregnant woman with HCV who is not immune to Hepatitis B. Safety of the Hepatitis A (HAV) vaccine in pregnancy has not been determined; although, given that HAV vaccine is produced from inactivated HAV, the theoretical risk to the fetus would be expected to be low .
As mentioned above, to date there is no approved antiviral therapy for pregnant or breastfeeding women with HCV; however, some animal model data has suggested that there may be safety data for antiviral treatment in pregnancy. The impact of maternal viremia level as it relates to risk for vertical transmission of HCV is not well-defined, but reports of mothers with undetectable HCV RNA levels reveal rare transmission. Using other infectious disease models, such as HBV and HIV, which clearly demonstrate risk reduction of vertical transmission with maternal viral load reduction, it seems reasonable that a decrease in viremia in pregnant women with HCV would thus reduce risk of vertical transmission. While we await further safety data regarding use of antiviral therapy for pregnant women with HCV, more research is being conducted currently on an observational level to determine at which threshold of viremia below which vertical transmission does not occur, and whether planned cesarean section prevents mother-to-child transmission (Eunice Kennedy Shriver National Institute of Child Health and Development Maternal Fetal Medicine Units Network) . While currently there remain more questions than answers regarding evaluation and treatment of HCV in pregnant and breastfeeding women, there is hope that ongoing research and safety trials might one day make treatment for pregnant women a possibility. We should also continue to educate our patients that HCV is not an indication at this time for planned cesarean section, and nor is HCV, unless there is known co-infection with HIV, a contraindication to breastfeeding.
Human Immunodeficiency Virus
For women with opioid use disorder, the risk of exposure to HIV is considerable. Women with injection substance use are at risk from sharing of needles, as well as sexual exposure from partners with unknown serostatus for HIV. Women with opioid use disorder, injection substance use, and working in the sex trade are among the highest risk for HIV exposure. Given that approximately 1 in 8 people living in the United States with HIV are unaware of their status , testing for HIV in pregnancy as per routine obstetric care will undoubtedly result in new diagnoses of HIV for women with opioid use disorder presenting for prenatal care.
When screening for HIV, the 4th generation antibody–antigen test is preferred. For women who test positive, confirmatory testing should be completed. For confirmed new diagnosis of HIV in pregnancy, additional testing is required as well as referral to specialty care (maternal-fetal medicine and/or infectious disease with experience treating women with HIV in pregnancy). At initial time of diagnosis, this additional testing should include CD 4 count, HIV RNA level, HAV, HBV, HCV, TB, CBC, CMP, and syphilis. Women should also receive or be referred for resistance testing for antiretroviral therapy. Women should be assessed for need for prophylaxis against opportunistic infection, following current HIV treatment guidelines . Best practice also includes screening for interpartner violence and/or need for referral of patient’s partner for testing or treatment. Assessing for need for immunization should also be completed: HAV, HBV, influenza, pneumococcus, HPV, and Tdap are all recommended for HIV positive women without documented immunity or recent immunization. A dating ultrasound should also be completed as early as possible in pregnancy to aid in planning for timing and route of delivery later in pregnancy [25–27].
Although the routes of vertical transmission of HIV in pregnancy are not perfectly understood, there does appear to be increased risk for transmission in labor and delivery. One proposed mechanism is maternal–fetal microtransfusion across the placenta, especially during uterine contractions. Another exposure risk during delivery includes exposure to maternal genital secretions and blood during vaginal delivery [28, 26]. There is also significant data to support that risk of vertical transmission of HIV is directly related to concentration of HIV RNA in maternal plasma, referred to as the viral load. For women with HIV and a viral load of less than 1,000 copies per mL, the risk for vertical transmission is as low at 2 percent [25, 26, 29].
The treatment of HIV in pregnancy is targeted at improving maternal health, but also reducing risk of vertical transmission to the fetus. Early treatment for pregnant women with HIV consisted of intrapartum zidovudine (ZDV) plus postexposure prophylaxis of the newborn for 6 weeks after birth. This treatment resulted in a significant reduction in vertical transmission rates of HIV, from greater than 25 percent with no care to 8 percent with ZVD and postexposure prophylaxis for the neonate. With the advent of combination therapy and antiretroviral therapy (ART), there are more options for targeted treatment to maximize both maternal and fetal wellbeing [26, 30].
Current recommendations are to begin ART as early as possible in pregnancy. Treatment should then be modified based on resistance testing results, but ART should not be delayed until this testing is complete. Early initiation of ART recognizes the need to reduce maternal HIV viral load to as low as possible, with the goal of viral load being undetectable. As most ART regimens take between 12 and 24 weeks for complete viral suppression, initiation of ART as early as possible gives the best opportunity for complete viral suppression by time of delivery. Current guideline recommendations for monitoring of HIV viral load include at baseline, 2–4 weeks after initiation or change in ART, monthly until RNA is undetectable, and then every 3 months through the remainder of pregnancy. A viral load should also be checked between 34 and 36 weeks to assist patient and provider shared decision making regarding timing and mode of delivery (Figure 7.4) [25–27, 29, 31].
|Diagnosis of STI during current pregnancy|
|Illicit drug use during current pregnancy|
|Exchange of sex for money or drugs|
|Multiple sex partners during current pregnancy|
|Signs/symptoms of acute HIV during pregnancy|
|Living in region with increased incidence of HIV in childbearing women|
|Partner with known HIV-positive serostatus|