Substance Use Disorder in Pregnancy

Question 1

Epidemiology

Answer 1

33% adults who access drug services are women of reproductive age

Tobacco > Alcohol > cannabis > other illicit substances

Polysubstance use is common + psych comorbidities, environmental stressors, limited/disrupted parental care

Question 2

Social problems

Answer 2

Housing, crime, children in care/abuse

Co-existent addictions – alcohol or smoking

Malnutrition – iron, vitamin B, C

Risk of viral infections – HIV, Hep B

Question 3

Alcohol

Answer 3

more cognitive and behavioural abnormalities:

Crosses the placenta

Intake of < 100g per week (~ 2 glasses of wine or 1 pint of beer) is not associated with adverse effects

• Miscarriage, stillbirth, infant mortality, congenital abnormalities, LBW, preterm delivery, SGA, FGR
• Foetal alcohol spectrum disorders with later neurodevelopmental abnormalities
• Prenatal drinking associated with long-term effects – cognitive/behavioural change, adverse language outcomes
• Executive functioning defects, psychosocial consequences in adulthood
• Massive doses, > 2g/kg of body weight (17 drinks per day), have been associated with foetal alcohol syndrome (FAS)

FAS is irreversible

=> poor growth, birth defects, seizures and other neuro problems, developmental delay, behavioural issues (babies may be fussy or jittery, and have trouble sleeping)

Characteristic facies: smooth philtrum, thin vermillion, small palpebral fissures

This is not consistently seen in infants born to women who are heavy consumers

Mx:

• Involve social workers to arrange for formal psychiatric/ addiction assessment
• Vitamin B supplements
• Iron supplements

Question 4

Smoking

Answer 4

more distinct outcomes:

ACUTELY REDUCES PLACENTAL PERFUSION

Smoking < 5 cigarettes per day has barely discernible obstetric effects

MOTHER

• Damage to umbilical cord structure
• Miscarriage
• Increased risk of ectopic pregnancy
• Placental abruption
• preterm birth

FOETUS

• Increased foetal mortality
• LBW
• FGR
• Stillbirth
• SIDS

Mx:

• Smoking cessation @ booking app

Question 5

Cannabis

Answer 5

Preterm labour, LBW, SGA, increased NICU admission

o Prenatal cannabis use linked to:

• Adverse consequences of growth of foetal and adolescent brains
• Reduced attention and executive functioning skills
• Poorer academic achievement
• Behavioural problems

Question 6

Cocaine

Answer 6

Cocaine use results in vasospasm and so placental pathology

MATERNAL

• PROM
• Placental abruption - VERY IMP RISK FACTOR
• Preterm birth

FOETAL

• LBW, SGA 
• NAS

Similar to cocaine, methamphetamine use linked with shorter gestational ages, LBW, foetal loss, developmental and behavioural defects, preeclampsia, gestational HTN, intrauterine foetal death

Question 7

Opioids

Answer 7

MOTHER

• Placental pathology e.g. abruption and insufficiency
• Premature rupture of membranes, preterm labour
• Pre-eclampsia
• Miscarriage, stillbirth
• PPH

FOETUS

• Greater risk of LBW
• Respiratory problems
• 3rd trimester bleeding
• Toxaemia
• Mortality
• Growth deficiency
• Microcephaly
• Behavioural problems
• SIDS 

Neonatal abstinence syndrome (NAS) à opiate exposure in utero triggers postnatal withdrawal syndrome

45-94% of infants exposed to opioids in utero (inc. methadone, buprenorphine)

NAS = substantial neonatal morbidity + increased healthcare utilisation

Presentation:

• Irritability
• Feeding difficulties
• Tremors
• Hypertonia
• Emesis
• Loose stools
• Seizures
• Respiratory distress

Most babies do not require medical treatment for NAS, however, the length of the withdrawal process varies

Neonatal abstinence syndrome (NAS) -> opiate exposure in utero triggers postnatal withdrawal syndrome

• 45-94% of infants exposed to opioids in utero (inc. methadone, buprenorphine)
• NAS = substantial neonatal morbidity + increased healthcare utilisation

Question 8

Management of opioid use

Answer 8

Try NOT to reduce opiate dose too rapidly in pregnancy

Sudden detoxification can be dangerous for the baby, especially in the 3rd trimester where mild maternal withdrawal can lead to foetal stress, foetal distress, stillbirth

For HEROIN USERS: Administer the lowest effective dose of methadone liquid, divided into 3 doses per day

Screen for infections e.g. Hepatitis B and HIV

Question 9

General symptoms and signs

Answer 9

Tiredness/ fatigue, sleepiness

Depression

Antepartum haemorrhage

Headaches

Tremors

Restlessness, agitation

Mood changes- irritability, euphoria, dysphoria

Heroin- pinpoint pupils, needle track marks

Cocaine use- dilated pupils, hyperreflexia

Question 10

Investigations/ Prognosis

Answer 10

Ix

• Basic observations
• Bloods- FBC, U&Es, LFTs (gGT for women with alcohol misuse), toxicology screen
• Foetal CTG if indicated

Management

• AIM: stabilise the mother’s drug-taking abits and ensure contact with social/ care workers and psychiatric/ drug liaison services as appropriate
• MULTIDISCIPLINARY CARE!

Prognosis

• Cessation of smoking by 15 weeks reduces the risk as much as quitting BEFORE pregnancy
• Cessation of drug use in pregnancy will help improve maternal and foetal outcomes, preventing complications from occurring