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Maternal drug abuse—effects on the child
Mini-symposium
D r u g abuse
effects on the
Maternal drug abuse child
T. Lissauer, K. Ghaus, R. Rivers Table 1 Drugs taken by notified drug addicts in the UK in 1992
Although everyone is aware of the increase in drug abuse in the U K and worldwide, the true scale of the problem is difficult to assess. In the U K the number of drug abusers notified to the Home Office has been rising by 20% annually to a total of 24 700 in 1992 (Fig. 1). Notified drug abusers mainly take multiple drugs including narcotics and are concentrated in the inner cities, particularly London and the large cities in the North West of England. The proportion addicted to heroin fell to about 70%, but this is balanced by a rise in methadone, which now accounts for over 40% of notifications. Less than 10% were reported to abuse cocaine (Table 1). The proportion of people injecting drugs continues to fall
20000
m 15000
g 10000 Z
5000
F 1989
1990
1901
1992
Year
Fig. I--Increase in number of drug abusers in the UK notified to the Home Office.
FRCP, Consultant Paediatrician, Karena Ghaus MRCP, Senior Registrar (Temporary), Rodney Rivers FRCP, Reader in Paediatrics, Department of Paediatrics, St Mary's Hospital and Medical School,Paddington, London, W2 1PG. Correspondenceand requests for reprints to TL. Tom Lissauer
Current Paediatrics (1994) 4, 235-239 9 1994 Longman Group Ltd
Number of persons
(%)
Heroin Methadone Cocaine Morphine Others Total
16,984 10,011 1,951 321 640 24,703
(69%) (41%) (8%) (1%) (2%)
and now represents 54% of the total. A quarter of notified drug abusers are female, almost all of child bearing age. Much less is known about the recreational use of cocaine and other drugs, though they are undoubtedly increasingly available throughout the country. It is difficult to evaluate the extent of the problem in pregnancy. There have been a number o f prevalence studies in the USA based on urine analysis at antenatal clinics. A study in Florida detected marihuana in 12%, cocaine in 3%, opiates in 0.3% and alcohol in 1%. 1 At Boston City Hospital, 30% of pregnant women either admitted use or were positive for marihuana or cocaine (14% for marihuana, 5% for cocaine and 12% for both substances)) The prevalence for women testing positive for cocaine ranges from 6-27%. 3-5 The largest experience in the management o f babies born to drug abusing mothers comes from the USA. However, there are marked differences from the U K in the drugs abused, in the abusers' lifestyles, in the social support available and the laws relating to the welfare of children. Management needs to be tailored to local conditions. This article will be confined to considering the effects of illicit drugs on the fetus and child and their management. There are many reasons why relating specific adverse developmental outcomes to individual drugs is problematic and the results of studies are
25000
1988
Type of drug
235
236
CURRENT PAEDIATRICS
often conflicting. Many drug abusers take multiple drugs, including alcohol and cigarettes; they often provide inaccurate information about their drug use, the routes of intake and dosage; drug purity also varies and their lifestyle has many adverse features in regard to the provision of appropriate child care.
Cocaine The leaves of the coca bush, indigenous to parts of South America, have been chewed for many centuries to produce a feeling of euphoria and well-being, a lowering of social inhibitions and to reduce fatigue and appetite. It is, though, only relatively recently that cocaine has become widely available in the US and Europe. In its natural form it can be taken by nasal insufflation (snorting) or intravenously. Crack is a highly purified derivative, with a lower melting point, which makes it suitable for smoking (free basing). It derives its name from the crackling sound when it vaporises.
Effects on the fetus and infants It has proved extremely difficult to identify the adverse effects of cocaine on the fetus and infant. It has been proposed that there are two modes of action whereby cocaine may adversely affect the fetus (Table 2). 6 The first results from the indirect effects of cocaine causing maternal and fetal vasoconstriction. In the mother, stimulation of the pregnant uterus results in an increased rate of preterm delivery. Poor placental blood flow results in intrauterine growth retardation with microcephaly. In the fetus, vasoconstriction may result in intracerebral ischaemic lesions and limb reduction defects. Cocaine can also have direct effects by interfering with dopamine and noradrenaline re-uptake at the post-synaptic junction, which causes central nervous system signs from increased neurotransmission. The infants are irritable, have abnormal sleep patterns and increased tone; abnormal EEG's have been reported. The central nervous signs occur during the first 5 days after birth when cocaine has been used in the immediate antepartum period, Any signs are generally Table 2
Effects o f cocaine on the fetus and infants
Vasoconstriction
Blocked neurotransmitter uptake
Fetal hypoxia, stillbirth
Central nervous system toxicity: - fetal hyperactivity - irritability - abnormal sleep patterns - increased tone - abnormal EEG
Placental abruption S p o n t a n e o u s abortion Preterm labour Precipitate labour Intrauterine g r o w t h retardation Microcephaly Intracerebral ischaemic lesions Limb reduction defects
mild and rarely require any treatment, in contrast to those from withdrawal from narcotics. The symptoms diminish with elimination of cocaine from the infant. Cocaine is highly lipid soluble and is therefore readily transmitted to breast milk. Seizures in a newborn infant following a breast feed from a mother shortly after taking crack have been described, and we have also observed such an incident. It would therefore seem prudent to advise against breastfeeding in mothers taking cocaine. An increased risk of sudden infant death syndrome has been reported, 7 but another study has failed to shown an association,s
Marihuana Marihuana is the most widely used illicit drug amongst women of childbearing age in the USA. The drug crosses the placenta, though maternal blood levels are 2-6 times higher than in the fetus. Although some reports have ascribed intrauterine growth retardation, preterm delivery and neurobehavioural abnormalities in the infant to its use, none appear to be consistent. 9
Narcotics Natural opiates such as morphine are harvested from the opium producing poppy, Papaver somniferum. Synthetic and semi-synthetic opioids include heroin and methadone. Heroin is the drug of choice amongst addicts as it is highly lipid soluble and acts quickly. Methadone is widely used as part of drug maintenance programmes. The management of the pregnant narcotic abuser continues to be controversial. Many centres will try to convert heroin users to methadone. The advantages are that methadone can be taken orally and has a long half-life, the latter reducing the risk to the fetus of death from sudden drug withdrawal. It also removes the need to use illicit drugs. Finding the equivalent dose of methadone can be problematic. In addition, high dose methadone appears to produce particularly severe withdrawal in newborn infants, but in women who are able to keep to a lowdose methadone (<20mg/day) regimen there are usually no or only mild clinical features of neonatal withdrawal. Another area of controversy is whether or not pregnant women should be maintained on methadone or encouraged to stop taking the drug completely. Any detoxification should be done gradually, monitoring the fetus for increased movements and tachycardia indicating withdrawal. Clonidine, an alpha adrenergic agonist has also been used as an alternative to methadone to suppress opioid withdrawal. Complications of maternal narcotic use in the fetus include intrauterine growth retardation and preterm delivery; fetal hyperactivity, tachycardia on the CTG and stillbirth from fetal withdrawal. 1~There does not
MATERNAL D R U G ABUSE Table 3
Signs of neonatal drug withdrawal
EFFECTS ON THE CHILD
237
vomiting and diarrhoea are features ascribed to autonomic nervous system dysfunction. When there is a history of drug abuse, the constellation of clinical features associated with withdrawal are readily recognised. When there is no maternal history or drug abuse is denied, its recognition is much more difficult. Drug withdrawal must be remembered when no other cause of these features can be identified. In order to try to introduce some objectivity into assessing clinical severity, scoring systems have been devised. Some are very detailed, but a relatively simple system we have found easy to use is shown in Figure 2.11 To avoid over weighting of related clinical signs, e.g. yawning and hiccoughs, both abnormalities related to the autonomic nervous system, the presence of one of the pair scores one point. Treatment is commenced if the score is 6 on 2 consecutive occasions, 4 h apart, or if seizures occur.
Central nervous system Irritability and restlessness Tremulousness with skin excoriation High pitched cry Hypertonia Sleep disturbance Seizures Autonomic system dysfunction Yawning Sweating Nasal stuffiness Sneezing Temperature instability Hiccoughs Gastrointestinal Poor feeding with disorganised sucking Vomiting/diarrhoea Weight loss and failure to thrive Respiratory Tachypnoea
appear to be an increased prevalence of congenital malformations.
Drug treatment Medical care of the infant
Many of" the features of narcotic withdrawal appear to be from excitation of noradrenergic cells of the locus coeruleus in the brainstem. Suppression of these cells can be achieved with morphine or clonidine, whilst the effects of their activation, with projections to hypothalamus, thalamus, cortex and spinal cord, may be partially blocked by chlorpromazine. The objectives of treatment are the suppression of abnormal clinical signs and the avoidance of excessive sedation and other side effects. Swaddling, quiet and darkness reduce irritability but do not reduce the need for medication.
At delivery, giving the infant naloxone is contraindicated as it may precipitate acute withdrawal, which could be fatal. The neonate may develop clinical features of withdrawal, also called the neonatal abstinence syndrome (Table 3). The most noticeable features are those of the central nervous system with irritability and restlessness, a high pitched cry or, most seriously, seizures. Feeding is often poor, with disorganised sucking and swallowing accompanied by weight loss. Yawning, sneezing and sweating,
Name Baby's No. D.O.B
Withdrawal Chart Please chart 4 hourlyor when necessary Irritability with scratching
Excessivewakefulness High-pitchedcry Tremors
Hypertonicity Convulsions Hyperthermia Tachypnoea Vomiting
> 38~ _>60 per min
Diarrhoea
Yawning Hiccoughs Salivation Stuffy Nose Sneezing
I .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Sweating Dehydration Score
Time
Date Fig. 2 - - A chart used to score the severity of drug withdrawal according to clinical signs. The maximum score is 10 (Reproduced from Rivers R P A, Archives of Disease in Childhood 1986; 61: 1236-1239, with permission of the author and publishers).
238
CURRENT PAEDIATRICS
A number of drugs have been used: 12 p a r e g o r i c - - was widely used in the US but is now
less popular as it contains not only morphine and opium alkaloids but also camphor, benzoic acid and a high concentration of alcohol, each of which may have adverse side effects. m o r p h i n e and m e t h a d o n e - - these have become widely used. They are particularly useful in treating seizures. The prolonged plasma half-life of methadone makes dose adjustment difficult. p h e n o b a r h i t o n e - - is long acting and may cause sedation and depressed sucking behaviour. It does not control gastrointestinal or nasal features or prevent seizures. d i a z e p a m - - may cause sedation, poor sucking behaviour and hypotension, and has a long half-life. chlorpromazine - - has been widely used in the UK. There has been concern that it may cause seizures. Sedation and poor feeding may occur. It does not effectively prevent seizures, which occur in 20-40% of symptomatic infants. clonidine - - has been used infrequently in neonates. It may cause hypotension. Drug treatment of withdrawal symptoms may involve an initial loading dose and maintenance regimen, the daily drug dosage then being gradually reduced. It is not uncommon for this to take several weeks in severe cases. In addition to the scores on the withdrawal chart, the baby's feeding and weight chart are helpful. Infants whose symptoms are poorly controlled have disorganised feeding and do not gain weight. Over treatment causes lethargy and poor feeding with failure to gain weight. Satisfactory control is accompanied by avid feeding and rapid weight gain. Two regimens involving the use of methadone or morphine are given. Methadone 0.1 mg/kg given every 6 h with increases of 0.05 mg/kg/dose until control of withdrawal is achieved. After 24 h the daily dose may be divided b.d. and then reduced by 10-20% per day. Doses of 0.6-1.2 mg/kg/day may be required to achieve control. The baby should be observed for 72h following discontinuation of therapy. Morphine (as 0.4 rag/rot of diluted i.v. formulation) can be given at a dose of 0.04 mg/kg (0.1 ml/kg) orally every 4h, increasing by 0.02mg/kg (0.05 ml/kg) per dose until control is achieved. Dose reductions may be achieved by reducing the dose frequency on a daily basis to 6-hourly, 8-hourly, 12-hourly and 24-hourly, discontinuing at a dose of 0.04 mg/kg. The baby should be observed for 48 h following discontinuation of therapy. Because there may not be equivalent receptormediated cell suppression by the different opiates, selection of treatment might be best based on the use of the drug to which the mother was exposed, substituting morphine for heroin when indicated. Seizures are best treated by a single dose of
parenteral methadone (0.25mg/kg) or morphine (0.15mg/kg) followed by maintenance therapy. Causes of the seizure other than withdrawal should always be sought and monitoring for apnoea maintained.
Breast-feeding In mothers taking methadone or intravenous narcotics there has been concern about the drug level in breast milk. 13 Measurements of drug concentrations have shown extremely low levels in the milk, so we have not discouraged breast-feeding on these grounds alone. Mothers known to be HIV positive or at high risk are currently advised against breast-feeding in developed countries where there is a safe alternative.
Associated risks Hepatitis B
Mothers who abuse narcotics are at increased risk of hepatitis B and their hepatitis B surface antigen status should be measured during pregnancy. This is usually done early in pregnancy and will not identify those who develop the infection later in pregnancy. We advise hepatitis B immunisation for all babies of drug abusing mothers even if the mother is hepatitis B surface antigen negative. H I V infection
Intravenous drug users are at markedly increased risk of HIV infection. If their HIV status is unknown they should be counselled about the advantages and disadvantages of testing. The advantage for a mother who is HIV positive to be aware of her status is that vertical transmission can be reduced. Avoiding breastfeeding halves the vertical transmission rate. 14 Data are emerging indicating reduction in transmission from 25 to 8% with zidovudine treatment to the mother and to the infant for the first few weeks of life. It also appears that delivery by caesarean section reduces transmission. For the infant, identification of positive maternal HIV status allows testing for transmission, close monitoring for complications, prophylaxis against p n e u m o e y s t i s earinii to be given and the appropriate management of any illness. S e x u a l l y t r a n s m i t t e d diseases
As the mothers are at increased risk of sexually transmitted diseases the infants should be observed for transmitted infection e.g. conjunctivitis from c h l a m y d i a trachomatis or gonococcus.
Overall management Many of the mothers will have contact with a drug dependency or needle exchange unit, social services
MATERNAL DRUG ABUSE--EFFECTS ON THE CHILD
and other health and welfare agencies. Planning the care of the mother and her baby will also involve the obstetrician, midwives, paediatrician, health visitor and general practitioner. The management plan we have adopted is: A n t e n a t a l l y - - a planning meeting is held, so that information can be shared and postnatal care for the mother and baby planned. It is also arranged for the parents and paediatrician to meet so that care of the baby can be discussed. A f t e r birth - - the mother and baby are transferred to the postnatal ward where the baby is observed for signs of drug toxicity or withdrawal. Observations are for up to 5 days for mothers taking cocaine alone or 2 weeks if on methadone or heroin. A cranial ultrasound scan is performed to check for any intracerebral ischaemic lesions or haemorrhage. Babies requiring treatment are looked after in the neonatal unit. A second planning meeting or case conference is held prior to discharge, when discharge and followup arrangements are made. A f t e r discharge - - Regular advice and monitoring of the baby's growth and well-being is provided by the health visitor and there is usually input from social services. The babies tend to remain irritable and difficult to settle. Response to social interaction is poor, and they are often difficult and frustrating babies to look after. There is also an increased risk of sudden infant death. The baby's development is monitored by the paediatrician and general practitioner. Although there are a number of reports suggesting that many of the babies have language and other developmental delay followed by poor school performance, outcome for these children is profoundly influenced by their social environment. Whether or not they are more likely to become drug abusers as teenagers and adults is unknown. Overall, it is the disorganised social life-style of the mothers and their partners that proves to be the greatest problem in caring for the baby. The constant attention and demands of a newborn baby are often incompatible with the need to obtain drugs and fund the habit; the altered periods of highs and drug withdrawal experienced by the parents are not conducive to stable care. Many lead chaotic lives, have employment and housing problems and are in trouble with the law. A survey of 50 drug users attending a drug dependency unit found that 78% funded their drug habit through illegal activities (30% mainly from shoplifting, 18% by dealing in drugs, 12% by burglary, 6% by pick-pocketing and
239
6% by prostitution). The plans for the baby made at the antenatal planning meeting are often radically changed once the infant is born and the constant demands of a newborn baby are realised. Most of the babies are discharged home with their mother, but some go to a mother and baby unit or foster care; some are placed on a Child Protection Register. A long term follow-up of 85 symptomatic babies discharged from this unit between 1968 1983, showed that: 25% were living with both parents; 20% were with their mother; 12% were with their father and 36% were with relatives or adopted or fostered. 15 Six of the parents had died of drug related problems; there were four deaths amongst the children of the study group, highlighting the risk of drug abuse not only for adults but also for their children.
References 1. Chasnoff I J, Londress H J, Barrett ME. The prevalence of illicit drug or alcohol use during pregnancy and discrepancies in mandatory reporting in Pirellas County, Florida. N Engl J Med 1990; 332: 1202. 2. Zuckerman B, Frank DA, Higson R et al. Effects of maternal marijuana and cocaine use on fetal growth. N Engl J Med 1989; 320: 762. 3. Schutzman D, Frankfield-ChernicoffM, Clatterbaugh M, Singer J. Incidence of intrauterine cocaine exposure in a suburban setting. Pediatrics 1991: 88; 825-827. 4. Neerhof M, MacGregor S, Retzity S, Sullivan T. Cocaine abuse in pregnancy: Peripartum prevalence and perinatal outcome. Am J Obstet Gynecol 1989; 161: 633-638. 5. Matera C, Warner W, Moomjy M, Fink D, Fox M. Prevalence of use of cocaine and other substances in an obstetric population. Am J Obstet Gynecol 1990; 163:797 801. 6. Chasnoff IJ. Cocaine and Pregnancy: Clinical and Methodologic Issues. Clin Perinatol 1991; 18:113-123. 7. Chasnoff 1J, Burns W J, Schnoll SH, Burns KA. Cocaine use in pregnancy. N Engl J Med 1985; 313: 666-9. 8. Bauchner H, Zuckerman B, McClain M, Frank D, Fried LE, Kayne H. Risk of sudden infant death syndrome among infants with in utero exposure to cocaine. J Pediatr 1988; 113: 831-4. 9. Day NL, Richardson GA. Prenatal Marijuana Use: Epidemiology, Methodologic Issues, and Infant Outcome. Clin Perinatol 1991; 18: 77-91. 10. Stone ML, Salermo LJ, Green M et al. Narcotic addiction in pregnancy. Am J Obstet Gynaecol 1971; 109: 716-723. 11. Rivers RPA. Neonatal opiate withdrawal. Arch Dis Child 1986; 61:1236 1239. 12. Committee on Drugs. Neonatal drug withdrawal. Pediatrics 1983; 72: 895-902. 13. Committee on Drugs. American Academy of Pediatrics. Transfer of drugs and other chemicals into human milk. Pediatrics 1989; 84: 924-936. 14. Dunn DT, Newell ML, Ades AE, Peckham CS. Risk of human immunodeficiency virus type 1 transmission through breastfeeding. Lancet 1992; 340:585 588. 15. Williams MJH. The problems of children born to drug addicts. Maternal and Child Health 1983; 8: 258-263.
D r u g abuse
effects on the
Maternal drug abuse child
T. Lissauer, K. Ghaus, R. Rivers Table 1 Drugs taken by notified drug addicts in the UK in 1992
Although everyone is aware of the increase in drug abuse in the U K and worldwide, the true scale of the problem is difficult to assess. In the U K the number of drug abusers notified to the Home Office has been rising by 20% annually to a total of 24 700 in 1992 (Fig. 1). Notified drug abusers mainly take multiple drugs including narcotics and are concentrated in the inner cities, particularly London and the large cities in the North West of England. The proportion addicted to heroin fell to about 70%, but this is balanced by a rise in methadone, which now accounts for over 40% of notifications. Less than 10% were reported to abuse cocaine (Table 1). The proportion of people injecting drugs continues to fall
20000
m 15000
g 10000 Z
5000
F 1989
1990
1901
1992
Year
Fig. I--Increase in number of drug abusers in the UK notified to the Home Office.
FRCP, Consultant Paediatrician, Karena Ghaus MRCP, Senior Registrar (Temporary), Rodney Rivers FRCP, Reader in Paediatrics, Department of Paediatrics, St Mary's Hospital and Medical School,Paddington, London, W2 1PG. Correspondenceand requests for reprints to TL. Tom Lissauer
Current Paediatrics (1994) 4, 235-239 9 1994 Longman Group Ltd
Number of persons
(%)
Heroin Methadone Cocaine Morphine Others Total
16,984 10,011 1,951 321 640 24,703
(69%) (41%) (8%) (1%) (2%)
and now represents 54% of the total. A quarter of notified drug abusers are female, almost all of child bearing age. Much less is known about the recreational use of cocaine and other drugs, though they are undoubtedly increasingly available throughout the country. It is difficult to evaluate the extent of the problem in pregnancy. There have been a number o f prevalence studies in the USA based on urine analysis at antenatal clinics. A study in Florida detected marihuana in 12%, cocaine in 3%, opiates in 0.3% and alcohol in 1%. 1 At Boston City Hospital, 30% of pregnant women either admitted use or were positive for marihuana or cocaine (14% for marihuana, 5% for cocaine and 12% for both substances)) The prevalence for women testing positive for cocaine ranges from 6-27%. 3-5 The largest experience in the management o f babies born to drug abusing mothers comes from the USA. However, there are marked differences from the U K in the drugs abused, in the abusers' lifestyles, in the social support available and the laws relating to the welfare of children. Management needs to be tailored to local conditions. This article will be confined to considering the effects of illicit drugs on the fetus and child and their management. There are many reasons why relating specific adverse developmental outcomes to individual drugs is problematic and the results of studies are
25000
1988
Type of drug
235
236
CURRENT PAEDIATRICS
often conflicting. Many drug abusers take multiple drugs, including alcohol and cigarettes; they often provide inaccurate information about their drug use, the routes of intake and dosage; drug purity also varies and their lifestyle has many adverse features in regard to the provision of appropriate child care.
Cocaine The leaves of the coca bush, indigenous to parts of South America, have been chewed for many centuries to produce a feeling of euphoria and well-being, a lowering of social inhibitions and to reduce fatigue and appetite. It is, though, only relatively recently that cocaine has become widely available in the US and Europe. In its natural form it can be taken by nasal insufflation (snorting) or intravenously. Crack is a highly purified derivative, with a lower melting point, which makes it suitable for smoking (free basing). It derives its name from the crackling sound when it vaporises.
Effects on the fetus and infants It has proved extremely difficult to identify the adverse effects of cocaine on the fetus and infant. It has been proposed that there are two modes of action whereby cocaine may adversely affect the fetus (Table 2). 6 The first results from the indirect effects of cocaine causing maternal and fetal vasoconstriction. In the mother, stimulation of the pregnant uterus results in an increased rate of preterm delivery. Poor placental blood flow results in intrauterine growth retardation with microcephaly. In the fetus, vasoconstriction may result in intracerebral ischaemic lesions and limb reduction defects. Cocaine can also have direct effects by interfering with dopamine and noradrenaline re-uptake at the post-synaptic junction, which causes central nervous system signs from increased neurotransmission. The infants are irritable, have abnormal sleep patterns and increased tone; abnormal EEG's have been reported. The central nervous signs occur during the first 5 days after birth when cocaine has been used in the immediate antepartum period, Any signs are generally Table 2
Effects o f cocaine on the fetus and infants
Vasoconstriction
Blocked neurotransmitter uptake
Fetal hypoxia, stillbirth
Central nervous system toxicity: - fetal hyperactivity - irritability - abnormal sleep patterns - increased tone - abnormal EEG
Placental abruption S p o n t a n e o u s abortion Preterm labour Precipitate labour Intrauterine g r o w t h retardation Microcephaly Intracerebral ischaemic lesions Limb reduction defects
mild and rarely require any treatment, in contrast to those from withdrawal from narcotics. The symptoms diminish with elimination of cocaine from the infant. Cocaine is highly lipid soluble and is therefore readily transmitted to breast milk. Seizures in a newborn infant following a breast feed from a mother shortly after taking crack have been described, and we have also observed such an incident. It would therefore seem prudent to advise against breastfeeding in mothers taking cocaine. An increased risk of sudden infant death syndrome has been reported, 7 but another study has failed to shown an association,s
Marihuana Marihuana is the most widely used illicit drug amongst women of childbearing age in the USA. The drug crosses the placenta, though maternal blood levels are 2-6 times higher than in the fetus. Although some reports have ascribed intrauterine growth retardation, preterm delivery and neurobehavioural abnormalities in the infant to its use, none appear to be consistent. 9
Narcotics Natural opiates such as morphine are harvested from the opium producing poppy, Papaver somniferum. Synthetic and semi-synthetic opioids include heroin and methadone. Heroin is the drug of choice amongst addicts as it is highly lipid soluble and acts quickly. Methadone is widely used as part of drug maintenance programmes. The management of the pregnant narcotic abuser continues to be controversial. Many centres will try to convert heroin users to methadone. The advantages are that methadone can be taken orally and has a long half-life, the latter reducing the risk to the fetus of death from sudden drug withdrawal. It also removes the need to use illicit drugs. Finding the equivalent dose of methadone can be problematic. In addition, high dose methadone appears to produce particularly severe withdrawal in newborn infants, but in women who are able to keep to a lowdose methadone (<20mg/day) regimen there are usually no or only mild clinical features of neonatal withdrawal. Another area of controversy is whether or not pregnant women should be maintained on methadone or encouraged to stop taking the drug completely. Any detoxification should be done gradually, monitoring the fetus for increased movements and tachycardia indicating withdrawal. Clonidine, an alpha adrenergic agonist has also been used as an alternative to methadone to suppress opioid withdrawal. Complications of maternal narcotic use in the fetus include intrauterine growth retardation and preterm delivery; fetal hyperactivity, tachycardia on the CTG and stillbirth from fetal withdrawal. 1~There does not
MATERNAL D R U G ABUSE Table 3
Signs of neonatal drug withdrawal
EFFECTS ON THE CHILD
237
vomiting and diarrhoea are features ascribed to autonomic nervous system dysfunction. When there is a history of drug abuse, the constellation of clinical features associated with withdrawal are readily recognised. When there is no maternal history or drug abuse is denied, its recognition is much more difficult. Drug withdrawal must be remembered when no other cause of these features can be identified. In order to try to introduce some objectivity into assessing clinical severity, scoring systems have been devised. Some are very detailed, but a relatively simple system we have found easy to use is shown in Figure 2.11 To avoid over weighting of related clinical signs, e.g. yawning and hiccoughs, both abnormalities related to the autonomic nervous system, the presence of one of the pair scores one point. Treatment is commenced if the score is 6 on 2 consecutive occasions, 4 h apart, or if seizures occur.
Central nervous system Irritability and restlessness Tremulousness with skin excoriation High pitched cry Hypertonia Sleep disturbance Seizures Autonomic system dysfunction Yawning Sweating Nasal stuffiness Sneezing Temperature instability Hiccoughs Gastrointestinal Poor feeding with disorganised sucking Vomiting/diarrhoea Weight loss and failure to thrive Respiratory Tachypnoea
appear to be an increased prevalence of congenital malformations.
Drug treatment Medical care of the infant
Many of" the features of narcotic withdrawal appear to be from excitation of noradrenergic cells of the locus coeruleus in the brainstem. Suppression of these cells can be achieved with morphine or clonidine, whilst the effects of their activation, with projections to hypothalamus, thalamus, cortex and spinal cord, may be partially blocked by chlorpromazine. The objectives of treatment are the suppression of abnormal clinical signs and the avoidance of excessive sedation and other side effects. Swaddling, quiet and darkness reduce irritability but do not reduce the need for medication.
At delivery, giving the infant naloxone is contraindicated as it may precipitate acute withdrawal, which could be fatal. The neonate may develop clinical features of withdrawal, also called the neonatal abstinence syndrome (Table 3). The most noticeable features are those of the central nervous system with irritability and restlessness, a high pitched cry or, most seriously, seizures. Feeding is often poor, with disorganised sucking and swallowing accompanied by weight loss. Yawning, sneezing and sweating,
Name Baby's No. D.O.B
Withdrawal Chart Please chart 4 hourlyor when necessary Irritability with scratching
Excessivewakefulness High-pitchedcry Tremors
Hypertonicity Convulsions Hyperthermia Tachypnoea Vomiting
> 38~ _>60 per min
Diarrhoea
Yawning Hiccoughs Salivation Stuffy Nose Sneezing
I .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Sweating Dehydration Score
Time
Date Fig. 2 - - A chart used to score the severity of drug withdrawal according to clinical signs. The maximum score is 10 (Reproduced from Rivers R P A, Archives of Disease in Childhood 1986; 61: 1236-1239, with permission of the author and publishers).
238
CURRENT PAEDIATRICS
A number of drugs have been used: 12 p a r e g o r i c - - was widely used in the US but is now
less popular as it contains not only morphine and opium alkaloids but also camphor, benzoic acid and a high concentration of alcohol, each of which may have adverse side effects. m o r p h i n e and m e t h a d o n e - - these have become widely used. They are particularly useful in treating seizures. The prolonged plasma half-life of methadone makes dose adjustment difficult. p h e n o b a r h i t o n e - - is long acting and may cause sedation and depressed sucking behaviour. It does not control gastrointestinal or nasal features or prevent seizures. d i a z e p a m - - may cause sedation, poor sucking behaviour and hypotension, and has a long half-life. chlorpromazine - - has been widely used in the UK. There has been concern that it may cause seizures. Sedation and poor feeding may occur. It does not effectively prevent seizures, which occur in 20-40% of symptomatic infants. clonidine - - has been used infrequently in neonates. It may cause hypotension. Drug treatment of withdrawal symptoms may involve an initial loading dose and maintenance regimen, the daily drug dosage then being gradually reduced. It is not uncommon for this to take several weeks in severe cases. In addition to the scores on the withdrawal chart, the baby's feeding and weight chart are helpful. Infants whose symptoms are poorly controlled have disorganised feeding and do not gain weight. Over treatment causes lethargy and poor feeding with failure to gain weight. Satisfactory control is accompanied by avid feeding and rapid weight gain. Two regimens involving the use of methadone or morphine are given. Methadone 0.1 mg/kg given every 6 h with increases of 0.05 mg/kg/dose until control of withdrawal is achieved. After 24 h the daily dose may be divided b.d. and then reduced by 10-20% per day. Doses of 0.6-1.2 mg/kg/day may be required to achieve control. The baby should be observed for 72h following discontinuation of therapy. Morphine (as 0.4 rag/rot of diluted i.v. formulation) can be given at a dose of 0.04 mg/kg (0.1 ml/kg) orally every 4h, increasing by 0.02mg/kg (0.05 ml/kg) per dose until control is achieved. Dose reductions may be achieved by reducing the dose frequency on a daily basis to 6-hourly, 8-hourly, 12-hourly and 24-hourly, discontinuing at a dose of 0.04 mg/kg. The baby should be observed for 48 h following discontinuation of therapy. Because there may not be equivalent receptormediated cell suppression by the different opiates, selection of treatment might be best based on the use of the drug to which the mother was exposed, substituting morphine for heroin when indicated. Seizures are best treated by a single dose of
parenteral methadone (0.25mg/kg) or morphine (0.15mg/kg) followed by maintenance therapy. Causes of the seizure other than withdrawal should always be sought and monitoring for apnoea maintained.
Breast-feeding In mothers taking methadone or intravenous narcotics there has been concern about the drug level in breast milk. 13 Measurements of drug concentrations have shown extremely low levels in the milk, so we have not discouraged breast-feeding on these grounds alone. Mothers known to be HIV positive or at high risk are currently advised against breast-feeding in developed countries where there is a safe alternative.
Associated risks Hepatitis B
Mothers who abuse narcotics are at increased risk of hepatitis B and their hepatitis B surface antigen status should be measured during pregnancy. This is usually done early in pregnancy and will not identify those who develop the infection later in pregnancy. We advise hepatitis B immunisation for all babies of drug abusing mothers even if the mother is hepatitis B surface antigen negative. H I V infection
Intravenous drug users are at markedly increased risk of HIV infection. If their HIV status is unknown they should be counselled about the advantages and disadvantages of testing. The advantage for a mother who is HIV positive to be aware of her status is that vertical transmission can be reduced. Avoiding breastfeeding halves the vertical transmission rate. 14 Data are emerging indicating reduction in transmission from 25 to 8% with zidovudine treatment to the mother and to the infant for the first few weeks of life. It also appears that delivery by caesarean section reduces transmission. For the infant, identification of positive maternal HIV status allows testing for transmission, close monitoring for complications, prophylaxis against p n e u m o e y s t i s earinii to be given and the appropriate management of any illness. S e x u a l l y t r a n s m i t t e d diseases
As the mothers are at increased risk of sexually transmitted diseases the infants should be observed for transmitted infection e.g. conjunctivitis from c h l a m y d i a trachomatis or gonococcus.
Overall management Many of the mothers will have contact with a drug dependency or needle exchange unit, social services
MATERNAL DRUG ABUSE--EFFECTS ON THE CHILD
and other health and welfare agencies. Planning the care of the mother and her baby will also involve the obstetrician, midwives, paediatrician, health visitor and general practitioner. The management plan we have adopted is: A n t e n a t a l l y - - a planning meeting is held, so that information can be shared and postnatal care for the mother and baby planned. It is also arranged for the parents and paediatrician to meet so that care of the baby can be discussed. A f t e r birth - - the mother and baby are transferred to the postnatal ward where the baby is observed for signs of drug toxicity or withdrawal. Observations are for up to 5 days for mothers taking cocaine alone or 2 weeks if on methadone or heroin. A cranial ultrasound scan is performed to check for any intracerebral ischaemic lesions or haemorrhage. Babies requiring treatment are looked after in the neonatal unit. A second planning meeting or case conference is held prior to discharge, when discharge and followup arrangements are made. A f t e r discharge - - Regular advice and monitoring of the baby's growth and well-being is provided by the health visitor and there is usually input from social services. The babies tend to remain irritable and difficult to settle. Response to social interaction is poor, and they are often difficult and frustrating babies to look after. There is also an increased risk of sudden infant death. The baby's development is monitored by the paediatrician and general practitioner. Although there are a number of reports suggesting that many of the babies have language and other developmental delay followed by poor school performance, outcome for these children is profoundly influenced by their social environment. Whether or not they are more likely to become drug abusers as teenagers and adults is unknown. Overall, it is the disorganised social life-style of the mothers and their partners that proves to be the greatest problem in caring for the baby. The constant attention and demands of a newborn baby are often incompatible with the need to obtain drugs and fund the habit; the altered periods of highs and drug withdrawal experienced by the parents are not conducive to stable care. Many lead chaotic lives, have employment and housing problems and are in trouble with the law. A survey of 50 drug users attending a drug dependency unit found that 78% funded their drug habit through illegal activities (30% mainly from shoplifting, 18% by dealing in drugs, 12% by burglary, 6% by pick-pocketing and
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6% by prostitution). The plans for the baby made at the antenatal planning meeting are often radically changed once the infant is born and the constant demands of a newborn baby are realised. Most of the babies are discharged home with their mother, but some go to a mother and baby unit or foster care; some are placed on a Child Protection Register. A long term follow-up of 85 symptomatic babies discharged from this unit between 1968 1983, showed that: 25% were living with both parents; 20% were with their mother; 12% were with their father and 36% were with relatives or adopted or fostered. 15 Six of the parents had died of drug related problems; there were four deaths amongst the children of the study group, highlighting the risk of drug abuse not only for adults but also for their children.
References 1. Chasnoff I J, Londress H J, Barrett ME. The prevalence of illicit drug or alcohol use during pregnancy and discrepancies in mandatory reporting in Pirellas County, Florida. N Engl J Med 1990; 332: 1202. 2. Zuckerman B, Frank DA, Higson R et al. Effects of maternal marijuana and cocaine use on fetal growth. N Engl J Med 1989; 320: 762. 3. Schutzman D, Frankfield-ChernicoffM, Clatterbaugh M, Singer J. Incidence of intrauterine cocaine exposure in a suburban setting. Pediatrics 1991: 88; 825-827. 4. Neerhof M, MacGregor S, Retzity S, Sullivan T. Cocaine abuse in pregnancy: Peripartum prevalence and perinatal outcome. Am J Obstet Gynecol 1989; 161: 633-638. 5. Matera C, Warner W, Moomjy M, Fink D, Fox M. Prevalence of use of cocaine and other substances in an obstetric population. Am J Obstet Gynecol 1990; 163:797 801. 6. Chasnoff IJ. Cocaine and Pregnancy: Clinical and Methodologic Issues. Clin Perinatol 1991; 18:113-123. 7. Chasnoff 1J, Burns W J, Schnoll SH, Burns KA. Cocaine use in pregnancy. N Engl J Med 1985; 313: 666-9. 8. Bauchner H, Zuckerman B, McClain M, Frank D, Fried LE, Kayne H. Risk of sudden infant death syndrome among infants with in utero exposure to cocaine. J Pediatr 1988; 113: 831-4. 9. Day NL, Richardson GA. Prenatal Marijuana Use: Epidemiology, Methodologic Issues, and Infant Outcome. Clin Perinatol 1991; 18: 77-91. 10. Stone ML, Salermo LJ, Green M et al. Narcotic addiction in pregnancy. Am J Obstet Gynaecol 1971; 109: 716-723. 11. Rivers RPA. Neonatal opiate withdrawal. Arch Dis Child 1986; 61:1236 1239. 12. Committee on Drugs. Neonatal drug withdrawal. Pediatrics 1983; 72: 895-902. 13. Committee on Drugs. American Academy of Pediatrics. Transfer of drugs and other chemicals into human milk. Pediatrics 1989; 84: 924-936. 14. Dunn DT, Newell ML, Ades AE, Peckham CS. Risk of human immunodeficiency virus type 1 transmission through breastfeeding. Lancet 1992; 340:585 588. 15. Williams MJH. The problems of children born to drug addicts. Maternal and Child Health 1983; 8: 258-263.