Management of Labor and Delivery
Women who are undergoing methadone maintenance in pregnancy are frequently entering labor with great trepidation and excessive guilt. These women are at high risk of both intrapartum and postpartum complications. 19 On occasion, caretakers may lack the necessary understanding and empathy to deal effectively with these women. It is most beneficial to assume an unbiased, non-judgmental, compassionate and supportive approach toward these patients. The intrapartum period should be managed by giving the usual dose of methadone at approximately the same time of day as the patient is accustomed to receiving it. Narcotics may be given for pain control in doses that are customary for other obstetrical patients. Drugs that function as agonist-antagonist agents, e.g., nubain and stadol should not be given, as they may precipitate maternal and fetal withdrawal symptoms, with consequent fetal distress in labor. 6 Should an infant suffer from respiratory depression immediately after birth, it is important to remember that narcotic antagonists such as narcan are likely to precipitate acute, severe withdrawal symptoms in the infant and must be avoided. Respiratory depression in these newly born infants must be managed with mechanical ventilation and supportive care.
Post-Delivery Dosing Schedule
The mother's regular methadone dosing schedule should be maintained as closely as possible after she has delivered. She should be encouraged to arrange for her methadone doses to continue without interruption after discharge from the hospital. It is usually possible for the mother to begin to taper her methadone dose toward the end of the postpartum period, i.e., 4 to 6 weeks after delivery, when maternal metabolism and blood volume have returned to the pre-pregnant state.
Management of the Neonate
The pediatrician or neonatologist caring for the newborn infant should be notified of the delivery prior to, if possible, or as soon as the infant is born. Pertinent information to be communicated includes the exact maternal methadone dose and time of last administration. The half-life of methadone in the adult is about 24 to 36 hours and varies with maternal ability to metabolize the drug. ( ref. 9 )
The incidence and severity of withdrawal symptoms in the newborn do not always correlate well with maternal dose, particularly if other drugs are used concurrently; therefore it is difficult to predict the probability and intensity of the neonatal abstinence syndrome (NAS) in any individual baby. 20 21 In general, however, higher doses of maternal drug late in the pregnancy tend to be associated with earlier and more severe withdrawal symptoms in the neonate. 22 The timing of onset of neonatal abstinence syndrome varies among individuals, but averages about 48 to 52 hours after the last maternal dose. 23