Heroin misuse in pregnancy can have an adverse impact on the woman (obstetric and non-obstetric effects) and, because heroin easily crosses the placental barrier, the baby as well. Non-obstetric adverse effects include physical (malnutrition, poor dental hygiene, infections, etc), psychological (feelings of blame and guilt, self harm, depression, etc) and social (relationship difficulties, domestic violence, involvement in crime, etc).² Specific obstetric complications include antepartum haemorrhage, low birth weight, and higher neonatal mortality³; and non-specific complications include premature rupture of membranes, premature birth, and intrauterine growth retardation.⁴ Ongoing heroin use during pregnancy has also been shown to be associated with use of other illicit drugs, poor engagement with antenatal services, frequent use of emergency care facilities, and social adversity.⁵ Although heroin and other opioids have no specific teratogenic potential, 48–94% of children exposed in utero will have opioid withdrawals at birth or neonatal abstinence syndrome⁶ (NAS). A brief description of its characteristics and treatment is given in the discussion section.

The patient derives from a family of three, with no history of substance dependence in the family. Her parents separated when she was a child, but she maintains excellent relationship with both of them. Her sister is extremely supportive to her; her younger brother is autistic. She was born and raised locally, attended normal mainstream schools, and was average academically. She has no formal educational qualifications and has never been in structured employment. She has committed numerous acquisitive offences (shoplifting) to finance her drug use. Until recently, she was in an abusive relationship with a drug using partner, but is now separated and lives with her three children.

Following the initial assessment, the patient was started on methadone 40 ml daily (1mg/1ml, oral solution). In addition, her treatment package consisted of one-to-one psychological input from her keyworker and further support to address her social needs. She started making progress in treatment and reduced her heroin and cocaine use significantly. Three years into treatment, she was pregnant for a third time, but this went unrecognised until she was 16 weeks pregnant. Soon her care was transferred to our specialist mother and baby nurse. This nurse remained the patient’s keyworker throughout her further treatment and she coordinated her care with other professionals such as antenatal staff, maternity services, general practitioner, and social services. There were regular multidisciplinary reviews of her care and progress in treatment. A comprehensive care plan was drawn up, with the patient’s active participation, with extensive input from all professionals involved in her treatment. She was also informed and educated about the rationale and benefits of methadone treatment and the risk of NAS. Adequate opportunities were provided for her to understand the risk of NAS, its symptoms, and how it could be treated. During the second trimester, at her request, the dose of methadone was gradually reduced to 17 ml daily. At this dose, she remained clean of heroin and denied any craving or withdrawal symptoms. She was receiving regular antenatal care and her pregnancy was uneventful.

At 37 weeks gestation, the patient gave birth normally to a healthy baby. He weighed 8 lbs (3.6 kg) and showed no signs of NAS. They were kept in hospital for 3 days to monitor the baby for NAS, after which they were discharged.

NAS is a set of behavioural and physiological signs and symptoms in the newborn that is a result of abrupt psychoactive substance withdrawal at birth. It occurs in the majority of infants exposed to opioids in utero and estimates vary from 48–94%.⁶ NAS can vary in its onset, duration and severity depending on the severity of maternal dependence and fetal metabolism. Although symptoms of NAS are usually apparent within 24–72 hours after birth, occasionally this could be as late as 10 days. Typical characteristics of opioid NAS are irritability, high pitched cry, vomiting, diarrhoea, hypertonicity, tremor, tachypnoea and, in severe case, seizures. Some have noted methadone to cause NAS that is delayed in onset, of longer duration, and of greater severity.⁸ Most cases of NAS only require supportive treatment measures, but severe cases will need pharmacological treatment. Drugs such as morphine, tincture of opium, barbiturates and benzodiazepines have been used with good success. If adequately treated, NAS causes no long term damage to the child.

In drug using women, pregnancy often presents a window of opportunity for change: motivation levels tend to be high; they are more amenable to treatment; and hence it is an ideal time to intervene. In our case, she was already engaged in treatment (and was on methadone) when she found out that she was pregnant. Her engagement with treatment services continued to be very good. Furthermore, her care and keyworking was taken over by our specialist mother and baby nurse, who also coordinated her care with other agencies and professionals. This included ongoing liaison and regular meetings with all professionals involved in her care: the midwife, obstetrician, GP and social services. Such a comprehensive and coordinated multidisciplinary treatment package also gave the opportunity to address her psychosocial needs. The benefits of such treatment programmes have been reported previously in literature by Day et al⁹ who showed that they result in high levels of engagement and pronounced reduction of illicit drug use.

Another important aspect of our patient’s care was the gradual reduction and eventual successful maintenance on 17 ml of methadone daily during her last trimester. She was also informed of the risk of NAS and was adequately prepared for the same. She was told that methadone was a safe drug to be on during pregnancy and when she requested a detoxification, the risks of it during the last trimester (premature labour, low birth weight, neonatal morbidity, etc) were mentioned, and on balance she chose to be on a low maintenance dose of methadone. Given that the rates of NAS among those on methadone are as high as 90%, it is perhaps surprising that our patient’s child did not have NAS. But evidence suggests that specialised multidisciplinary management of drug use during pregnancy can reduce the risk of NAS to as low as 26%.¹⁰ In fact, a good outcome for the mother and baby in this case is perhaps not all that surprising: better antenatal care, healthier pregnancies and healthier babies were outcomes reported in outpatient methadone programmes for pregnant women.¹¹

We acknowledge that this is only one case and hence has obvious generalisability limitations. We also acknowledge, given that addiction can be a chronic disorder and given her past history, we cannot yet comment on her long term prognosis. Nevertheless, it seems reasonable to draw some valid conclusions. First, pregnancy is a window of opportunity for change. Second, methadone substitution treatment is safe and results in good outcomes for the mother and the baby. Thirdly, although NAS is very common it is not inevitable and measures can be put in place to minimise the risk of NAS. Finally, clinicians need to be aware of this syndrome, its presentation, its impact on the mother, and measures that can be put in place to minimise the risk.