Substance Use Disorder in Pregnancy

Epidemiology and Scope of the Problem

The impact of substance use disorder (SUD) upon pregnancy will be reviewed in this chapter. SUD is considered by many obstetricians to be a problem best managed by other disciplines. However, it is inevitably our problem as well. All physicians have likely contributed to overprescribing habit-forming medications to women of childbearing age, and the structure of prenatal care lends itself to an intense time of engagement in medical care during which women are uniquely motivated to optimize their health. With the proper education and tools, obstetricians stand to be fully equipped to initiate treatment when SUD is identified.

The ongoing opioid epidemic disproportionately affects women. A 2014 Substance Abuse and Mental Health Services Administration (SAMHSA) report showed female treatment admissions for opioid pain relievers (as the primary substance of abuse) outnumber male admissions in all age categories. The rate of opioid use during pregnancy is approximately 5.6 per 1000 live births, with one study reporting that greater than 85% of pregnancies in women with opioid use disorder (OUD) were unintended. This has significantly impacted not only maternal and child health but also has had a financial impact on society. In 2009 the cost of neonatal abstinence syndrome alone was $720,000,000, which increased to $1.5 billion in 2015, with approximately 80% of costs incurred by Medicaid systems.

Although opioids are the current focus nationally, previous decades have been impacted by cocaine or methamphetamines, and without a doubt a new illicit drug is on the horizon. Lessons learned from the opioid epidemic can provide a framework that may be applied to the next drug of abuse.

Addiction and the Chronic Disease Model

To optimize the care of pregnant women with SUD, it is important to understand it as a disease process independent of pregnancy . SUD is a primary, chronic disease of brain reward, motivation, memory, and related circuitry. Similar to chronic hypertension, type 2 diabetes, and asthma, without treatment or engagement in recovery activities, SUD is progressive and can result in disability or premature death. Such chronic diseases carry similar hallmarks: they are treatable with medications and intervention as well as they are prone to relapse at a rate of 50% to 60%, and combined with lifestyle changes, health status can be optimized. Although these diseases are not likely to be cured, they can be managed to reduce or eliminate symptoms.

SUD is associated with more stigma than other chronic diseases. As such, some people with SUD will not seek treatment, some doctors refuse to treat patients with addiction, and some pharmaceutical companies will not work toward developing new treatments for addicts. Over time, the stigma will likely diminish as a result of public education and broader acceptance of addiction as a chronic and treatable disease.

Highlighted is that SUD is a chronic disease so that obstetric providers can begin to medicalize our approach, rather than stigmatize pregnant women with SUD. In these cases, pregnancy is an acute and self-limited process imposed upon a chronic disease. In the same way that suboptimal control of blood sugars in pregnancies affected by diabetes may not prompt you to question the motives of a patient, relapse should be considered a part of the SUD disease process, rather than a transgression that builds barriers between providers and patients.

Neurobiology of Addiction

Many neurotransmitters have been implicated with regard to the effects of substances of abuse, but dopamine is consistently associated with the reinforcing effects. Drugs of abuse increase extracellular dopamine concentrations in ways that far surpass the effects of natural reinforcers such as nurturing, water, food, or sex. Because dopamine is a powerful reinforcer, it is easy to learn and repeat this pathway. Some substances of abuse directly increase dopamine (cocaine and methamphetamine), whereas others indirectly increase it via actions on other neurotransmitters such as γ-aminobutyric acid (GABA) that results in a loss of inhibitory control of dopamine (opioids, marijuana, and benzodiazepines). Common drugs of abuse and mechanisms of action are outlined in Table 8.1 .

Addiction can be conceptualized as a reward deficit disorder characterized by transition from controlled to impulsive and compulsive drug intake that is mediated by both positive and negative reinforcement . Initial use is characterized by the reinforcing effects of pleasure. Over time, however, one no longer uses substances to seek pleasure, rather negative reinforcement (a behavioral mechanism recruited to alleviate a negative emotional state in the absence of a drug) becomes the driver of continued use. Dopamine release occurs in the nucleus accumbens of the limbic system, which modulates neuronal activity in subcortical and cortical brain structures. When high levels of dopamine are encountered due to exposures to substances, abnormally high or prolonged dopamine-related neuronal activity in subcortical/cortical structures can produce abnormal messages about reward prediction and decision making. With prolonged drug exposure, regions of the prefrontal cortex are damaged. Drug-induced impairments of the prefrontal cortex can exert a twofold impact on addiction: first through its perturbed regulation of limbic reward regions, and second through its involvement in higher-order executive function. Therefore abnormalities in these frontal regions may underline both the compulsive nature of drug administration and the inability to control urgency to take drugs when exposed.

Although many humans have the potential to develop neuroadaptations that lead to addiction, not everyone does. There are many factors that may contribute to a predisposition to addiction, including genetics, age, environmental, and psychiatric comorbidities. It is estimated that 40% to 60% of vulnerability to addiction is attributed to genetic factors. Animal models suggest that several genes are involved in drug responses, and modification of those genes affects drug self-administration. Some candidate genes for drug responses in animals have been identified that correspond to genes and loci in human studies.

Exposure to drugs or alcohol during adolescence may result in different neuroadaptations than when exposures occur in adulthood, and the process of addiction is more likely to be triggered in the adolescent brain. Perhaps rendering adolescents vulnerable is the lack of development of the frontal cortex, with executive control, motivation, and decision making more able to be influenced by drug exposure.

Environmentally, factors associated with addiction are those that could be proxies for stress. SUD is associated with low socioeconomic status, poor parental support, within peer group deviancy, physical and psychological abuse, and drug availability. It is well established that those children affected by adverse childhood experiences are at high risk for SUD. Adverse childhood experiences include neglect; physical, emotional, and sexual abuse; a parent with a mental illness; being a victim of (or a witness to) violence in the home; divorce; substance abuse within the home; or an incarcerated family member.

For every adverse childhood experience identified, there is a two- to fourfold lifetime increase in SUD.

It is estimated that 50% to 60% of patients identified to have SUD have coexisting psychiatric diagnoses. It remains unclear if the reason for SUD is to self-medicate the underlying psychiatric disease or if substance use induces changes that increase the risk of mental illness. Co-occurrence may also reflect overlapping environmental, genetic, and neurobiologic factors for these disorders.

Screening, Brief Intervention, Referral to Treatment: SBIRT

Screening, brief intervention, and referral to treatment (SBIRT) is a public health approach to the delivery of early intervention and treatment services for individuals at risk of developing SUDs as well as those who have already developed these disorders. There are many ongoing initiatives to help with the referral process and encourage universal screening. In August 2017, the American Society of Addiction Medicine (ASAM) and American College of Obstetricians and Gynecologists (ACOG) produced a joint statement recommending that universal screening rely on validated tools, such as the 4Ps, National Institute on Drug Abuse (NIDA) quick screen, and CRAFFT screening tool for women aged 26 years or younger.

The 4P's has a sensitivity of 87% and specificity of 76% for identifying SUD in pregnancy. The NIDA quick screen has high reliability and high specificity and, if screen positive, reflexes to the Alcohol, Smoking and Substance Involvement Screening Test (ASSIST), which is a more detailed screen. The ASSIST has been validated worldwide with a sensitivity of 80% and sensitivity of 76% in discriminating substance use from substance abuse. A CRAFFT score of 2 or higher is 92% sensitive and 80% specific for identification of substance dependence. The simplicity of the single question: “How many times in the past year have you used an illegal drug or used a prescription medication for nonmedical reasons?” has been validated for the identification of drug use disorder in primary care. A positive response was 100% sensitive and 76.5% specific for identification of a drug use disorder. Although not validated in pregnancy, such a screening test would be attractive for implementation given its brevity.

Different from screening is biologic testing such as urine drug testing for drugs of abuse. Although universal screening for SUD is currently recommended, universal testing is not necessarily recommended. Clinicians must adhere to state laws for drug testing and seek consent to do so in those states where consent is required. Pregnant women should be informed of the potential ramifications of a positive test result, including any mandatory reporting requirements.

When considering biologic testing for SUD, there are many considerations. First, using universal testing with punitive implications may have a negative impact upon prenatal care. If pursuing testing, one must be reminded that a urine drug screen tells us only a single point in time, can easily be manipulated, and does not shed any light on the chronicity or extent of use. Although chronic use of marijuana can lead to detectable levels for weeks, most common drugs of abuse remain present 2 to 5 days ( Table 8.2 ).

Once identified as high risk based upon screening, establishment of a use disorder is the necessary next step. In pregnancy, this becomes simple, as continued use of illicit substances while pregnant is patho­gnomonic for a use disorder. ASAM diagnostic criteria also exist; using these criteria, a minimum of two to three criteria is required for a mild SUD diagnosis, whereas four to five is moderate, and six to seven is severe. Further classification of the disorder is based on the substance used. For example, OUD is specified instead of SUD, if opioids are the drug of abuse.

Once a use disorder is established, a brief intervention should be used. The basic goal for a patient identified with SUD is to reduce the risk of harm from continued use of substances. The greatest degree of harm reduction would obviously result from abstinence; however, the specific goal for each individual patient is determined by her use pattern, the consequences of her use, and the setting in which the brief intervention is delivered. Focusing on intermediate goals allows for more immediate successes in the intervention and treatment process. In pregnancy, intermediate goals might include transitioning from street drugs to medication-assisted treatment, decreasing frequency of use, attending the next meeting, or engaging in substance abuse counseling. Immediate successes are important to keep the client motivated.

It is common to use the skills of motivational interviewing when pursuing a brief intervention. The clinician practices motivational interviewing with five general principles in mind :

• 1

  Express empathy through reflective listening.

• 2

  Develop discrepancy between clients’ goals or values and their current behavior.

• 3

  Avoid argument and direct confrontation.

• 4

  Adjust to client resistance rather than opposing it directly.

• 5

  Support self-efficacy and optimism.

A basic tenet of motivational interviewing is to help the patient identify her goals and help the patient see that her current behavior will not help achieve those goals. Although providers may assume that a woman seeking care desires comprehensive treatment for SUD, she may simply be interested in receiving prenatal care. Until she is motivated toward behavioral change, one should provide prenatal care and continue to use brief intervention or motivational interviewing at each encounter to help guide the patient toward the most healthful option.

Essential to effective screening and brief intervention is the concept of trauma-informed care. The likelihood that a patient with SUD was exposed to adverse childhood experiences is significantly high, and therefore all such patients should be approached with the assumption they have endured trauma. Key steps to trauma-informed care include meeting client needs in a safe, collaborative, and compassionate manner; preventing treatment practices that retraumatize people with histories of trauma who are seeking help or receiving services; building on the strengths and resilience of clients in the context of their environments and communities; and endorsing trauma-informed principles in agencies through support, consultation, and supervision of staff. Implicit to trauma-informed care is the absence of judgment, retribution, or demeaning patients.

When brief intervention identifies a patient motivated for treatment, referral to treatment can be accomplished. This is perhaps the most difficult step of SBIRT. Although resources for mental health issues and SUD are lacking, pregnancy can increase the accessibility of resources in many states. Nineteen states have either created or funded drug treatment programs specifically targeted to pregnant women, and 17 states and the District of Columbia provide pregnant women with priority access to state-funded drug treatment programs. Some state perinatal quality collaboratives are focusing on facilitating resource mapping and linkage to services once a woman is identified to have SUD while pregnant.

Management of Pregnancies Affected by Substance Use Disorder