16.3 Substance Use Disorders: Alcohol, Nicotine, Cannabis & Opioid Use in Women

The SBIRT Framework in Women's Health

Substance use disorders (SUDs) in women represent complex, chronic neurobiological conditions influenced by sex-specific physiology, trauma history, stigma, and systemic health disparities. The Screening, Brief Intervention, and Referral to Treatment (SBIRT) framework is an evidence-based, universal public health model endorsed by SAMHSA and ACOG:

• Screening (S): Universal screening using validated tools across well-woman, preconception, and prenatal encounters identifies risky substance use before dependence or severe morbidity develops.
• Brief Intervention (BI): Structured, nonjudgmental clinical conversations utilizing motivational interviewing (MI). Clinicians explore ambivalence, provide health risk feedback, elicit change talk, and establish actionable harm reduction goals.
• Referral to Treatment (RT): Seamless, supportive handoffs to specialized outpatient or residential addiction care for patients with moderate-to-severe substance use disorders.

Clinicians must maintain trauma-informed, non-punitive communication. Stigma and the fear of child welfare involvement or criminal legal consequences represent the most substantial barriers preventing pregnant and parenting women from disclosing substance use and accessing medical care.

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Alcohol Use Disorder (AUD): Female Biological Vulnerability & Screening

Alcohol is the most prevalent teratogenic exposure in pregnancy. Women experience unique biological vulnerabilities to ethanol toxicity compared to men, progressing more rapidly from initial consumption to physiological dependence, alcoholic liver disease, dilated cardiomyopathy, and cognitive decline—a phenomenon termed the telescoping effect.

Pharmacokinetics & Biological Vulnerabilities in Women

1. Lower Gastric Alcohol Dehydrogenase (ADH) Activity: Women possess significantly lower levels of the enzyme alcohol dehydrogenase in the gastric mucosa. Consequently, women experience ~20% to 30% less first-pass gastric metabolism of ingested alcohol, allowing a greater proportion of unmetabolized ethanol to enter systemic circulation.
2. Lower Total Body Water & Higher Body Fat Percentage: Ethanol is a hydrophilic molecule that distributes into body water. Women have a lower average percentage of total body water (~52% vs. ~61% in men) and higher adipose tissue proportion. This smaller volume of distribution produces significantly higher peak Blood Alcohol Concentrations (BAC) than men for identical weight-adjusted consumption.

Consumption Definitions & Validated Screening Tools

• Risky / Heavy Drinking in Non-Pregnant Women: Consuming >3 standard drinks on any single day, or >7 standard drinks per week (>4/day or >14/week for men; 1 standard drink = 14 g pure ethanol, equivalent to 12 oz of 5% beer, 5 oz of 12% wine, or 1.5 oz of 80-proof spirits).
• Binge Drinking in Women: Consuming ≥4 standard drinks within ~2 hours, reaching BAC ≥0.08 g/dL (vs. ≥5 drinks in men).
• Pregnancy Standard: There is no known safe amount, timing, or type of alcohol during pregnancy or when attempting conception.

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Fetal Alcohol Spectrum Disorder (FASD)

Ethanol is a potent teratogen that freely crosses the placenta via passive diffusion; fetal BAC equilibrates with maternal levels within minutes. The immature fetal liver lacks functional ADH enzymes, relying entirely on maternal clearance and exposing fetal tissues to prolonged amniotic fluid recycling of ethanol and acetaldehyde.

Fetal Alcohol Spectrum Disorder (FASD) encompasses the spectrum of physical, cognitive, and behavioral deficits caused by gestational alcohol exposure. Fetal Alcohol Syndrome (FAS) represents the most severe diagnostic presentation, defined by a classic clinical triad:

1. Characteristic Facial Dysmorphisms:
   • Smooth Philtrum: Flattened or absent vertical ridges between the upper lip and nose.
   • Thin Vermilion Border: Markedly thin upper lip.
   • Short Palpebral Fissures: Reduced horizontal eye fissure length.
2. Growth Restriction: Prenatal and/or postnatal height or weight ≤10th percentile.
3. Central Nervous System (CNS) Impairment: Microcephaly (head circumference ≤10th percentile), structural brain malformations (corpus callosum agenesis), intellectual disability, executive functioning deficits, impulse control disorders, and severe attention deficits.

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Tobacco & Nicotine Use: Perinatal Morbidities & Cessation

Tobacco use during pregnancy remains a leading preventable cause of perinatal morbidity and mortality. Nicotine causes potent maternal and uterine vasoconstriction, while carbon monoxide binds fetal hemoglobin (>200 times higher affinity than oxygen), forming carboxyhemoglobin and shifting the oxygen dissociation curve to the left, causing profound fetal tissue hypoxia.

Perinatal Morbidities

• Obstetric Risks: Intrauterine growth restriction (IUGR; 150–250 g average birth weight deficit), placental abruption (2- to 3-fold increased risk), placenta previa, preterm premature rupture of membranes (PPROM), and spontaneous preterm delivery.
• Fetal/Neonatal Risks: Increased rates of stillbirth, neonatal mortality, and Sudden Infant Death Syndrome (SIDS).
• Gynecologic Risks: Accelerated follicular atresia leading to menopause 1–2 years earlier, reduced fecundability, and accelerated progression of cervical intraepithelial neoplasia (CIN).

The 5 As Behavioral Counseling Model

At every encounter, clinicians should employ the 5 As model:

1. Ask: Document tobacco and nicotine use status for every patient at every encounter.
2. Advise: Strongly urge quitting in a clear, personalized, supportive manner.
3. Assess: Determine readiness to make a quit attempt within the next 30 days.
4. Assist: Provide behavioral strategies, social support, and connect with 1-800-QUIT-NOW.
5. Arrange: Schedule follow-up contact within the first week after the target quit date.

Pharmacotherapy Guidelines

• Non-Pregnant Women: First-line treatments include combination Nicotine Replacement Therapy (NRT) (transdermal patch plus short-acting gum/lozenge), Varenicline (Chantix; partial nicotinic agonist), and Bupropion SR (Wellbutrin; contraindicated in seizure or eating disorders).
• Pregnant Women: Intensive psychosocial and behavioral therapy is first-line. If behavioral counseling fails, NRT may be considered under shared decision-making. Medicinal NRT eliminates fetal exposure to combustion carcinogens, carbon monoxide, and toxins. Intermittent formulations (gum, lozenges) are preferred over 24-hour patches to minimize total daily fetal nicotine exposure. Bupropion is second-line; varenicline lacks sufficient gestational safety data.

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Perinatal Cannabis Exposure

Cannabis is increasingly used during pregnancy, often misperceived as a safe, natural remedy for nausea. Delta-9-tetrahydrocannabinol (THC) crosses the placenta (fetal plasma levels 10%–30% of maternal) and concentrates heavily in human breast milk (milk-to-plasma ratio up to 8:1).

THC binds fetal cannabinoid type 1 (CB1) receptors, disrupting axonal guidance and synaptogenesis. In utero exposure is associated with lower birth weight and long-term neurocognitive deficits in exposed children, including impaired executive function, reduced attention span, memory deficits, and behavioral hyperactivity. ACOG and the AAP advise complete abstinence during preconception, pregnancy, and lactation; legal status does not imply developmental safety.

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Opioid Use Disorder (OUD) in Women: Harm Reduction & MAT in Pregnancy

Opioid Use Disorder (OUD) is a chronic, relapsing brain disease requiring comprehensive screening (NIDA Quick Screen, DAST-10) and harm reduction. Clinicians should co-prescribe naloxone nasal spray (Narcan 4 mg) for overdose reversal (safe during pregnancy in acute emergencies) and educate on fentanyl test strips and syringe service programs.

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Neonatal Opioid Withdrawal Syndrome (NOWS) & Breastfeeding

Neonatal Opioid Withdrawal Syndrome (NOWS) occurs in 50% to 80% of neonates with chronic in utero opioid exposure, manifesting with tremors, hypertonia, high-pitched crying, tachypnea, vomiting, and loose stools.

• Eat, Sleep, Console (ESC) Model: Replaces rigid scoring algorithms by prioritizing non-pharmacologic rooming-in, skin-to-skin holding, swaddling, and quiet environments. Pharmacotherapy (morphine/methadone) is reserved only for infants unable to eat or sleep despite optimal supportive care.
• Breastfeeding: Strongly encouraged for mothers maintained on stable methadone or buprenorphine without active illicit drug use or HIV infection. Minimal medication passes into milk, promoting maternal-infant bonding and significantly reducing NOWS severity.