INFANTS OF MOTHERS WHO ABUSE DRUGS
Saturday, August 16, 2008
The problem of newborn infants born to mothers who abuse drugs is increasing in all communities. The drugs most commonly abused are tobacco, alcohol, marijuana, and cocaine. Because these mothers may abuse many drugs and give an unreliable history of drug usage, it may be difficult to pinpoint which drug is causing the morbidity seen in a newborn infant. Early hospital discharge makes discovery of these infants based on physical findings and abnormal behavior much more difficult.
1. COCAINE
Cocaine is currently the most commonly abused illicit drug, identified in up to 20–40% of pregnant women on urban delivery services; moreover, cocaine is often used in association with other drugs. The obstetric effects include maternal hypertension, decreased uterine blood flow, fetal hypoxemia, and uterine contractions. The rates of stillbirth, placental abruption, and preterm labor are increased two- to fourfold over nonusers, as is the rate of intrauterine growth restriction. Other effects in the fetus include microcephaly, cerebral infarctions, and congenital malformations caused by vascular infarcts such as intestinal atresia. In high-risk populations (no prenatal care, placental abruptions, and preterm labor), urine toxicology screens should be performed in mothers and infants. Analysis of meconium enhances diagnosis by indicating cumulative drug use prior to delivery.
As with other illegal drugs, cocaine seems to have long-term neurobehavioral effects, but multiple drug use and environmental factors preclude assigning specific effects to cocaine with certainty. The risk of SIDS is increased three to seven times over the risk in nonusers (0.5–1% of exposed infants).
2. OPIOIDS
The withdrawal signs in infants born to mothers who are addicted to heroin or who have been in maintenance methadone programs are similar. The clinical findings in infants born to methadone-maintained mothers may actually be more severe and prolonged than those seen with heroin. Clinical manifestations begin usually within 1–2 days. The clinical picture is typical enough to suggest a diagnosis even if a maternal history of drug abuse has not been obtained, although onset may not occur prior to discharge at 24 hours. Confirmation should be attempted with urine toxicology, but results will be negative unless the last drug dose was within a few days before delivery. Meconium can also be tested for illicit drugs and is more likely to be positive because the substances accumulate throughout pregnancy.
Treatment
Careful observation of the infant is a requirement. If opioid abuse or withdrawal is suspected, the baby is not a candidate for early discharge. Supportive treatment includes swaddling the infant and providing a quiet, dimly lighted environment. In general, specific treatment should be avoided unless the infant has severe symptoms or excessive weight loss. There is no single drug that has been uniformly effective, and the first choice varies among nurseries. The drugs that have been used include phenobarbital at an initial loading dose of 15–20 mg/kg intramuscularly, followed by a maintenance dose of 5 mg/kg/d in two divided doses, usually given orally. Opioids, diazepam, and clonidine have also been used, although the present authors prefer phenobarbital because of its safety and predictability. Treatment can be tapered over several days to a week. Both handling and procedures in the nursery should be kept to a minimum.
Prognosis
These infants demonstrate long-term neurobehavioral handicaps. However, it is difficult to distinguish the effects of in utero drug exposure from those of environmental influences during upbringing. Infants of opioid abusers have a four- to fivefold increased risk of SIDS.
3. ALCOHOL
The effects of alcohol on the fetus and the newborn are roughly proportionate to the degree of ethanol abuse. Fetal growth and development are adversely affected, and infants can experience withdrawal similar to that associated with maternal opioid abuse.
Children with full-blown fetal alcohol syndrome demonstrate postnatal growth deficiency and mild to moderate mental retardation. Those with lesser effects are at increased risk for attention-deficit/hyperactivity disorder and subtle developmental delays.
4. TOBACCO SMOKING
Smoking has been shown to have a negative impact on the growth rate of the fetus. The more the mother smokes, the greater the degree of intrauterine growth restriction. More recently, smoking during pregnancy has been associated with mild neurodevelopmental handicaps. The possible effects of multiple drug abuse apply to this category as well, and the potential interaction of multiple factors on fetal growth and development must be considered.
5. TOLUENE EMBRYOPATHY
Solvent abuse (paint, lacquer, or glue sniffing) is relatively common. The active organic solvent in these agents is toluene. Features attributable to in utero toluene exposure include prematurity, intrauterine growth retardation, microcephaly, craniofacial abnormalities similar to those associated with in utero alcohol exposure (see Table 1–15), nail hypoplasia, and renal anomalies. Long-term effects include postnatal growth deficiency and developmental delay.
6. OTHER DRUGS
There are two categories under which drugs and their effects on the newborn should be considered. In the first category are drugs to which the fetus is exposed because of its exposure to the mother. In many cases these are drugs prescribed for therapy of maternal conditions. The human placenta is relatively permeable, particularly to lipophilic solutes. Whenever possible, drug therapy of the mother should be postponed until after the first trimester. Drugs with potential fetal toxicity include antineoplastics, antithyroid agents, benzodiazepines, warfarin, lithium, angiotensin-converting enzyme inhibitors (eg, captopril, enalapril), and immunosuppressants.
In the second category are drugs the infant acquires from the mother during breast feeding. Most drugs taken by the mother at this time achieve some concentrations in breast milk, although they usually do not present a problem to the infant. If the drug is one that could have adverse effects on the baby, timing breast feeding to coincide with trough concentrations in the mother may be useful. The American Academy of Pediatrics (see second reference below) has reviewed drugs contraindicated in the breast-feeding mother.
1. COCAINE
Cocaine is currently the most commonly abused illicit drug, identified in up to 20–40% of pregnant women on urban delivery services; moreover, cocaine is often used in association with other drugs. The obstetric effects include maternal hypertension, decreased uterine blood flow, fetal hypoxemia, and uterine contractions. The rates of stillbirth, placental abruption, and preterm labor are increased two- to fourfold over nonusers, as is the rate of intrauterine growth restriction. Other effects in the fetus include microcephaly, cerebral infarctions, and congenital malformations caused by vascular infarcts such as intestinal atresia. In high-risk populations (no prenatal care, placental abruptions, and preterm labor), urine toxicology screens should be performed in mothers and infants. Analysis of meconium enhances diagnosis by indicating cumulative drug use prior to delivery.
As with other illegal drugs, cocaine seems to have long-term neurobehavioral effects, but multiple drug use and environmental factors preclude assigning specific effects to cocaine with certainty. The risk of SIDS is increased three to seven times over the risk in nonusers (0.5–1% of exposed infants).
2. OPIOIDS
- Essentials of Diagnosis & Typical Features
- Irritability, hyperactivity, incessant hunger and salivation.
- Vomiting, diarrhea, excessive weight loss.
- Tremors, seizures.
- Nasal stuffiness, sneezing.
- Often IUGR.
The withdrawal signs in infants born to mothers who are addicted to heroin or who have been in maintenance methadone programs are similar. The clinical findings in infants born to methadone-maintained mothers may actually be more severe and prolonged than those seen with heroin. Clinical manifestations begin usually within 1–2 days. The clinical picture is typical enough to suggest a diagnosis even if a maternal history of drug abuse has not been obtained, although onset may not occur prior to discharge at 24 hours. Confirmation should be attempted with urine toxicology, but results will be negative unless the last drug dose was within a few days before delivery. Meconium can also be tested for illicit drugs and is more likely to be positive because the substances accumulate throughout pregnancy.
Treatment
Careful observation of the infant is a requirement. If opioid abuse or withdrawal is suspected, the baby is not a candidate for early discharge. Supportive treatment includes swaddling the infant and providing a quiet, dimly lighted environment. In general, specific treatment should be avoided unless the infant has severe symptoms or excessive weight loss. There is no single drug that has been uniformly effective, and the first choice varies among nurseries. The drugs that have been used include phenobarbital at an initial loading dose of 15–20 mg/kg intramuscularly, followed by a maintenance dose of 5 mg/kg/d in two divided doses, usually given orally. Opioids, diazepam, and clonidine have also been used, although the present authors prefer phenobarbital because of its safety and predictability. Treatment can be tapered over several days to a week. Both handling and procedures in the nursery should be kept to a minimum.
Prognosis
These infants demonstrate long-term neurobehavioral handicaps. However, it is difficult to distinguish the effects of in utero drug exposure from those of environmental influences during upbringing. Infants of opioid abusers have a four- to fivefold increased risk of SIDS.
3. ALCOHOL
The effects of alcohol on the fetus and the newborn are roughly proportionate to the degree of ethanol abuse. Fetal growth and development are adversely affected, and infants can experience withdrawal similar to that associated with maternal opioid abuse.
Children with full-blown fetal alcohol syndrome demonstrate postnatal growth deficiency and mild to moderate mental retardation. Those with lesser effects are at increased risk for attention-deficit/hyperactivity disorder and subtle developmental delays.
4. TOBACCO SMOKING
Smoking has been shown to have a negative impact on the growth rate of the fetus. The more the mother smokes, the greater the degree of intrauterine growth restriction. More recently, smoking during pregnancy has been associated with mild neurodevelopmental handicaps. The possible effects of multiple drug abuse apply to this category as well, and the potential interaction of multiple factors on fetal growth and development must be considered.
5. TOLUENE EMBRYOPATHY
Solvent abuse (paint, lacquer, or glue sniffing) is relatively common. The active organic solvent in these agents is toluene. Features attributable to in utero toluene exposure include prematurity, intrauterine growth retardation, microcephaly, craniofacial abnormalities similar to those associated with in utero alcohol exposure (see Table 1–15), nail hypoplasia, and renal anomalies. Long-term effects include postnatal growth deficiency and developmental delay.
6. OTHER DRUGS
There are two categories under which drugs and their effects on the newborn should be considered. In the first category are drugs to which the fetus is exposed because of its exposure to the mother. In many cases these are drugs prescribed for therapy of maternal conditions. The human placenta is relatively permeable, particularly to lipophilic solutes. Whenever possible, drug therapy of the mother should be postponed until after the first trimester. Drugs with potential fetal toxicity include antineoplastics, antithyroid agents, benzodiazepines, warfarin, lithium, angiotensin-converting enzyme inhibitors (eg, captopril, enalapril), and immunosuppressants.
In the second category are drugs the infant acquires from the mother during breast feeding. Most drugs taken by the mother at this time achieve some concentrations in breast milk, although they usually do not present a problem to the infant. If the drug is one that could have adverse effects on the baby, timing breast feeding to coincide with trough concentrations in the mother may be useful. The American Academy of Pediatrics (see second reference below) has reviewed drugs contraindicated in the breast-feeding mother.
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