Neonatal Withdrawal Syndrome
Definition- infant whose mother has taken drugs that may potentially cause
neonatal withdrawal
Incidence- 5-10 % of deliveries are to women who have abused drugs (excluding
alcohol) during pregnancy
Pathophysiology- drugs of abuse are of low molecular weight and are usually
water-soluble and lipophilic. Both of these characteristics help the transfer of
these drugs across the placenta and into the fetus and amniotic fluid. The halflife of drugs is usually prolonged in the fetus compared to adults. Most drugs
either bind to CNS receptors or affect the release and reuptake of various
neurotransmitters. This may have a long-lasting effect on developing dendritic
structures. Some drugs are directly toxic to the fetal cells. The developing fetus
may be affected by the direct physiology of the drug- cocaine for example causes
teratogenic effects on the fetus, cocaine is a potent vasoconstrictor.
The major concern in infants of drug-abusing mothers is the long-term outcomes.
Limitations of studies on NWS- testing of the urine for drugs of abuse does not
reflect drug exposure through out pregnancy. Many women who use drugs are
multiple drug users and also drink alcohol and smoke cigarettes. Thus it is
difficult to isolate the effect of one drug.
Risk factors- associated with an increased incidence of drug abuse:
1) poor socioeconomic circumstances
2) poor antenatal care
3) teenage mother
4) poor education
Associated conditions
1) Infectious disease- hep. B syphilis, and other STDs
2) HIV
3) Multiple drug abuse
4) Poor nutritional status
5) Anemia
Obstetric complications
1)
2)
3)
4)
5)
6)
Premature delivery
PROM
Chorioamnionitis
Fetal distress
IUGR
Specific to cocaine: hypertension, abruption, cardiac arrhythmias,
myocardial ischemia, and infarction, CVA, respiratory arrest, fetal
demise
Diagnosis:
HISTORY- many drug users withhold information. Details of the extent,
quantity, and duration of the abuse are unreliable.
LABS- Urine only reflects the intake in the last few days prior to the
delivery. Urine may be obtained from both mom and baby (in whom it may
persist for a longer time).
False-positive immunoassays i.e. morphine positive if took in codeine
which is in cold and cough medicine. Poppy seeds can result in detectable
amounts of morphine in the urine. Chromatography or mass spectrometry may
determine the source
Meconium is a more sensitive test than urine for testing drug abuse and
reflects usage over a longer period than is detected by urine. Major disadvantage
is that the specimen requires processing prior to testing.
Hair is the most sensitive test available for drug abuse. Maternal hair can
be segmented and each analyzed for drug use. There is a qualitative relationship
between amounts of drug used and amounts incorporated in the hair. Hair can
also be obtained from the baby reflecting the last trimester. Hair may also be
obtained from the infant a long time after delivery should symptoms occur that
suggest in utero drug exposure that was previously unsuspected.
SIGNS AND SYMPTOMS- CNS irritability, altered neurobehavioral and
abnormal sympathetic activation. Drug abuse should be suspected in infants
exhibiting this behavior.
Hyperirritability
Increased deep tendon and primitive reflexes
Hypertonus
Tremors
High-pitched cry
Seizures
Wakefulness
Increased rooting reflexes
Uncoordinated or ineffectual sucking and swallowing
Regurgitation
Loose stools and diarrhea
Tachypnea
Yawning, hiccups
Sneezing, stuffy nose
Mottling
Fever
Failure to gain weight
Lacrimation
Scoring of symptoms- absince scoring is a way to assess withdrawal signs (see
attached).
Specific DrugsOpiates: onset of symptoms may occur minutes after delivery but usually
exposed babies due not show symptoms until 2-3 days of life. Clinical course is
variable. Restlessness, agitation, tremors and feeding problems may persist up
to 3-6 months. Prognosis is good, usually by 1-2 years of age they have good
catch up growth. Long-term follow up 5-6 year old children appear to function
in normal mental and motor development. Some children will require special
education classes. An environment can improve outcome significantly.
Cocaine: causes a decrease in uterine and placental blood flow with
consequent fetal hypoxemia. It also causes hypertension in the mother and the
fetus with a reduction in fetal cerebral blood flow. Symptoms are irritability,
tremors, hypertonia, frantic fist sucking, abnormal sleep pattern. Teratogen
because of the vascular affects. CNS anomalies, CV anomalies, limb reduction
defects, intestinal atresia and other malformations are all associated with cocaine.
Prognosis for growth is good; usually children have catch up growth by 1 year.
At 3-4 there are problems with expressive and receptive speech. Children are
described as being hyperactive, distractible and having problems with
socializing. Studies have shown no major difference in drug exposed vs. placebo
with respect to intellectual ability.
Alcohol: foremost drug used today. Ethanol is a depressant on the CNS.
The risk of affecting the fetus is related to the alcohol dose. The risk that an
alcoholic woman will have a child with fetal alcohol syndrome is 35-40%.
Alcohol is the major cause of mental retardation today.
Fetal alcohol syndrome
1) prenatal or postnatal growth retardation
2) CNS involvement irritability in infancy or hyperactivity in
childhood.
3) Facial dysmorphology- microcephaly, microphthalmus, or short
palpebral fissures a poorly developed philtrum, a thin upper
lip, and hypoplastic maxilla
Numerous congenital anomalies associated with FAS. Symptoms
may appear within 24 of delivery and include tremors, irritability,
hypertonicity, twitching and hyperventilation. Symptoms may be
severe but are usually short duration.
Barbiturates: symptoms are similar to opiates, except usually appear later. Most
infants become symptomatic at the end of the first week of life. The duration of
symptoms is usually 2-6 weeks.
Benzodiazepines: Symptoms similar to the narcotic withdrawal. The onset is
usually after birth.
Methamphetamine: Symptoms appear to be little, babies do seem to be smallerIUGR; after birth, more irritable and more difficulty with sleep. Prognosis is still
unclear, not that many studies also difficult population to follow, may be
associated neurocognitive deficits
Marijuana: studies have suggested shorter gestation and lower birth weight.
Prognosis is that these babies have higher incidence of ADHD
Treatment- Manifestations of drug withdrawal in some infants will resolve
within a few days and drug therapy is not required. The infant’s withdrawal
score should be assessed to monitor the progression of symptoms and the
adequacy of the treatment.
Supportive care1) minimal stimulation- attempt to keep the baby in a darkened
and quiet environment
2) Swaddling and positioning- use gentle swaddling and position
that encourages flexion rather than extension.
3) Prevent excessive crying with pacifier; cuddling ect.- feeding
should be on demand if possible.
Drug Treatment- see Pediatric Protocol
BreastfeedingEtOH- not recommended if in excess, in moderation is ok; with large amounts
causes drowsiness, diaphoresis, deep sleep, weakness, decreased linear growth ,
abnormal weight gain and decreased maternal production.
Nicotine- controversial because the question is whether to BF with smoking or
bottle-feed with smoking? ; Nicotine is present in the breast milk; possible
decreased milk production and decreased weight gain of the baby.
Amphetamine- not recommended; irritable and poor sleeping habits
Cocaine- not recommended; cocaine intoxication, irritability, vomiting, diarrhea,
tremulous and seizures
Heroine- not recommended; tremors, restlessness, vomiting and poor feeding
Marijuana- not recommended; no effect only one study
Methadone- recommended; does not appear to cross into breast milk
Long-term Management- During the first few years, children exposed to drugs
can have neurological problems. This places a difficult infant/child in a difficult
environment. Thus, close follow-up and social services involvement maybe
required.