Pregnant women who are dependent on opioids are at high risk of experiencing complications, generally as a result of:
- inadequate antenatal care;
- lifestyle factors including smoking, poor nutrition, high levels of stress and deprivation;
- repeated cycles of intoxication and withdrawal which can harm the foetus or precipitate premature labour or miscarriage.
- Methadone maintenance treatment:
- enables stabilisation of drug use and lifestyle,
- reduces or eliminates illicit opioid drug use and can help stabilise the in utero environment,
- facilitates access to comprehensive antenatal and postnatal care,
- does not increase the risk of congenital abnormalities in the foetus.
- Respiratory depression is not a significant problem in babies born to opioid dependent mothers receiving methadone maintenance treatment.
- Babies born to mothers on methadone maintenance treatment may experience a withdrawal syndrome. Available evidence gives little support to the existence of a relationship between the severity of the neonatal withdrawal syndrome and maternal methadone dose at delivery, and its occurrence is unpredictable. The benefits of methadone maintenance treatment for both the mother and the baby outweigh any risks from the neonatal withdrawal syndrome.
Dose reductions or detoxification during pregnancy
Neonatal withdrawal syndrome
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Management in pregnancyOpioid using pregnant women not already in treatment should be given high priority for assessment.
- Naloxone challenge should not be used in pregnant women because this may precipitate miscarriage or premature labour.
- Women already in methadone treatment who become pregnant can safely be maintained on their current dose.
- The bioavailability of methadone is decreased in the later stages of pregnancy due to increased plasma volume, an increase in plasma proteins which bind methadone and placental metabolism of methadone.
- It may be necessary to divide the daily dose and possibly to increase the dose in the third trimester of pregnancy to avoid withdrawal symptoms and minimise additional drug use.
Dose reductions or detoxification during pregnancyOpioid withdrawal in the first trimester of pregnancy is thought to be associated with an increased risk of miscarriage. Opioid withdrawal in the third trimester of pregnancy may be associated with foetal distress and death. Therefore, it is important that pregnant women are not exposed to withdrawal during the first and third trimesters.
If dose reductions or detoxification are to be undertaken during pregnancy these should be implemented in the second trimester.
- Dose reductions should only occur if the pregnancy is stable.
- The magnitude and rate of reduction needs to be flexible and responsive to the symptoms experienced by the woman concerned.
- Withdrawal symptoms should be avoided as much as possible as they cause considerable distress to the foetus.
- Careful monitoring of the pregnancy and foetus should be undertaken during dose reduction.
- In most instances, dose reductions of 2.5mg-5 mg per week are considered safe.
- Breast milk contains only small amounts of methadone and mothers can be encouraged to breastfeed regardless of methadone dose provided that they are not using other drugs.
- Breastfeeding may reduce the severity of the neonatal withdrawal syndrome.
- Women receiving high doses of methadone should be advised to wean their babies slowly to avoid withdrawal in the infant.
Neonatal withdrawal syndromeThe occurrence and severity of neonatal withdrawal is very unpredictable. Severity of withdrawal is probably ameliorated if neonates can be kept with their mothers rather than in the neonatal intensive care nursery, which may be stressful and overstimulating. However, this is not always possible.
All babies born to opioid dependent mothers should be observed by experienced staff for the development of withdrawal signs. It is recommended that a validated scale be used to assess the presence and severity of the neonatal withdrawal syndrome (see Appendix 3).
Top of pageCommon signs include:
- Irritability and sleep disturbances
- Fist sucking
- A shrill cry
- Watery stools
- General hyperactivity
- Ineffectual sucking
- Poor weight gain
- Dislike of bright lights
- Increased respiration rate
- Increased mucus production
- Increased response to sound
- Convulsions (rare).
Treatment of neonatal withdrawal syndrome is being considered by an expert group of Australian neonatologists and guidelines on management are being developed.
Supportive treatment involves minimising environmental stimuli and enhancing the baby's comfort and may include:
- Soothing by holding close to the body or swaddling.
- Keeping nostrils and mouth clear of secretions.
- Use of a dummy to relieve increased sucking urge.
- Frequent small feeds.
Indications for treatment:
- Weight loss (poor feeding, diarrhoea and vomiting, dehydration)
- Poor sleep
- Use the Finnegan Screening Instrument (Appendix 3). Treatment should be commenced when the score is 9 or more on two consecutive observations.
- Improvement should be monitored using scores on the screening tool.
- Morphine Oral Preparation - 2 mg/ml morphine dilution (can be further diluted)
- Tincture of opium - 0.4mg/ml dilution
- Paregoric (camphorated tincture of opium)
It is recommended that neonatal care be managed in collaboration with a specialist obstetric or paediatric service which is experienced in the management of babies born to drug dependent mothers.