Infants of opioid-dependent mothers: neurodevelopment at six months.

OBJECTIVE: The aim of this study is to describe infant neurodevelopment in 81 infants of methadone-prescribed opioid-dependent mothers. METHODS: Griffith MD scores at six months. RESULTS: Scores were lower in all domains compared to controls (p<0.001). Poly-drug exposed infants and those treated for neonatal abstinence syndrome performed significantly poorer (p=0.002 and p=0.008 respectively). CONCLUSIONS: Infants of methadone-maintained opioid-dependent mothers show poorer neurodevelopment at six months of age than non-drug exposed comparison infants. Developmental difficulties are confounded by delayed visual development. PRACTICE IMPLICATIONS: These highly vulnerable children merit close surveillance throughout infancy. SUMMARY: Griffith MD scores at six months in 81 infants born to methadone-prescribed opioid-dependent mothers were lower in all domains compared to controls (p<0.001). Poly-drug exposed infants and those treated for neonatal abstinence syndrome performed significantly poorer (p=0.002 and p=0.008 respectively). Co-existing visual problems were common.

Visual outcome in infants born to drug-misusing mothers prescribed methadone in pregnancy.

BACKGROUND: Flash visual evoked potentials (VEPs) were abnormal in a cohort of 100 neonates exposed to maintenance methadone in utero. This prospective cohort study now describes clinical visual and electrophysiological outcomes at 6 months. METHODS: Visual assessment included modified Atkinson test battery; strabismus, nystagmus, reduced visual acuity, delayed visual maturation or refractive error (>3 dioptres) defined a fail. Pattern-onset VEPs were recorded to 120', 60' and 15' checks. RESULTS: 81 drug-exposed and 26 comparison infants (79% and 52% of the original cohorts) were assessed at a median age of 27 weeks (range 26-30). 90% of drug-exposed infants had been additionally exposed to illicit drugs and 41% to excess alcohol in utero. 40% of the drug-exposed cohort failed clinical visual assessment: the relative risk of abnormal assessment was 5.1 (95% CI 1.3 to 20; p=0.02). Nystagmus was particularly common. VEP peak times were slower and amplitudes smaller in drug-exposed infants, of whom 70% had one or more abnormal VEP parameter. Abnormal visual outcome at 6 months was not associated with the pattern of additional drug exposure or a history of neonatal abstinence. CONCLUSIONS: Abnormal visual electrophysiology in infants born to drug-misusing mothers prescribed maintenance methadone persists to 6 months of age, and is associated with abnormal clinical visual assessment.

In utero drug and alcohol exposure in infants born to mothers prescribed maintenance methadone.

AIMS: To describe the prevalence of in utero alcohol and illicit drug exposure in infants born to mothers prescribed methadone in pregnancy, and to compare the accuracy of maternal interview with infant toxicology. METHODS: Urine and meconium samples were collected from 56 infants born to mothers prescribed methadone during pregnancy and a confidential interview conducted soon after delivery. Samples were screened for drugs of misuse and meconium samples analysed for the presence of fatty acid ethyl esters (FAEEs) to detect prenatal alcohol exposure. RESULTS: 91% of infants had been exposed to illicit drugs in utero, including opiates (73%), benzodiazepines (70%) and cannabinoids (59%). 47% of infants had elevated FAEEs. Meconium was more sensitive at detecting in utero drug exposure than urine toxicology (p<0.01 for opiates, benzodiazepines, cannabinoids) or maternal interview (p=0.03 for opiates, p<0.01 for cannabinoids). CONCLUSIONS: The majority of infants born to mothers prescribed methadone during pregnancy are exposed to polysubstance misuse, and almost one-half additionally exposed to excess alcohol.

Neonatal visual evoked potentials in infants born to mothers prescribed methadone.

OBJECTIVE: Drug misuse in pregnancy is associated with impaired infant visual development. Pilot data showed abnormal flash visual evoked potentials (VEPs) in neonates exposed to methadone in utero, but results were confounded by intrauterine growth restriction, gestation, and ongoing drug misuse. This large cohort study aimed to clarify the effects on neonatal flash VEPs of maternal drug misuse in pregnancy, including prescription of substitute methadone and subsequent development of neonatal abstinence syndrome. METHODS: This was a prospective cohort study. Flash VEPs were recorded within 3 days of birth from 100 healthy infants of drug-misusing mothers prescribed substitute methadone during pregnancy and 50 comparison infants matched for birth weight, gestation, and socioeconomic deprivation. VEP morphology was classified as mature, typical, or immature, and amplitudes and implicit times of the major waveform components measured. Drug exposure was determined by maternal history, maternal and infant urine, and meconium toxicology. RESULTS: VEPs from maternal drug-exposed infants were more likely to be of immature waveform (P < .001) and were smaller in overall amplitude (median 27 µV vs 39 µV, P < .001) compared with non-drug-exposed infants. Most infants were exposed to illicit drugs in addition to prescribed methadone; differences in VEP parameters were independently associated with maternal prescribed methadone and persisted after correcting for birth weight, cigarette smoking, and excess in utero alcohol exposure. CONCLUSIONS: In utero exposure to prescribed substitute methadone is associated with altered flash VEPs in the newborn period and these infants may warrant early clinical visual assessment.

Short-term outcomes following intrauterine transfusion in Scotland.

AIM: To describe neonatal outcomes following intrauterine transfusion (IUT) for severe Rhesus isoimmunisation from 1993 to 2004. RESULTS: 116 neonates who had undergone 457 IUTs (median 4, range 1-9) were identified. Three neonates died, all before 1995 (two because of hypoxic ischaemic multiorgan failure and one because of overwhelming Escherichia coli sepsis). 13 neonates (11%) were delivered by emergency Caesarean section following either IUT complication or spontaneous onset of preterm labour. They were more likely to require intubation (p<0.0001), on-going respiratory support (p=0.0007) and an exchange transfusion (p=0.007). 23 (20%) required an exchange transfusion and 63 (54%) at least one top-up transfusion. CONCLUSIONS: Management of severe Rhesus disease is associated with encouraging neonatal outcomes and most infants can be managed with phototherapy and a few top-up transfusions. IUT complications are rare but significantly increase neonatal mortality and morbidity. Antenatal counselling should address the likely postnatal course for these infants.

Impaired cardiac autonomic nervous control after cardiac bypass surgery for congenital heart disease.

We undertook a study to describe changes in heart rate variability (HRV) postoperatively in children undergoing cardiac bypass surgery for congenital heart disease (CHD). HRV was recorded for a 1-h period preoperatively and a 24-h period postoperatively in 20 children with CHD. We found a highly significant reduction in HRV in both time and frequency domain indices compared to preoperative values, which was sustained throughout the 24-h study period. There was a negative correlation between both time and frequency domain HRV measurements and length of cardiac bypass. HRV is reduced postoperatively and correlates with cardiac bypass time. Length of cardiac bypass time may be one mechanism whereby HRV is reduced following surgery.