Executive functioning, behavioural, emotional, and cognitive difficulties in school-aged children prenatally exposed to methadone.

Aim: The aim of this study was to examine executive function and emotional and behavioural difficulties of children aged between 8 and 10 years who had been prenatally exposed to methadone, compared to non-exposed peers. Methods: Prospective study: third follow-up of an original cohort of 153 children born to methadone-maintained opioid-dependent mothers 2008-2010: previous investigations were at 1-3 days and at 6-7 months of age. Carers completed the Strength and Difficulties Questionnaire (SDQ) and the Behaviour Rating Inventory of Executive Function, Second Edition (BRIEF®2). Results were compared between exposed and non-exposed groups. Results: Carers of 33 of 144 traceable children completed the measures. SDQ responses showed no group differences on subscales of emotional symptoms, conduct problems, or peer relationship problems. A marginally higher proportion of exposed children had a high or very high hyperactivity subscale score. Exposed children scored significantly higher on BRIEF®2 behavioural, emotional, and cognitive regulation indices, and on the global executive composite. After controlling for potentially confounding higher reported maternal tobacco use in the exposed group via regression modelling, the effect of methadone exposure reduced. Interpretation: This study supports evidence that methadone exposure in utero is associated with adverse neurodevelopmental outcomes in childhood. Challenges in studying this population include difficulties with long-term follow-up and controlling for potentially confounding factors. Further investigation of the safety of methadone and other opioids in pregnancy must include consideration of maternal tobacco use.

Variation in use of extended pulse oximetry testing to guide decisions around home oxygen provision for ex-preterm infants; A nationwide survey of UK neonatal units.

Differences in the diagnostic approach to bronchopulmonary dysplasia (BPD) may contribute to variation in reported BPD rates. We undertook a nationwide survey of UK neonatal units (NNUs) to describe criteria applied by neonatologists to conduct pulse oximetry studies in ex-preterm infants to assess their need for supplemental oxygen near discharge, as well as criteria applied to interpret saturation studies. Responses from 112 (64.7%) NNUs demonstrated wide variation in both criteria used to select infants for assessment and thresholds for interpretation. Neither demonstrated a clear relationship with reported BPD rates. Variation in clinical practice requires further scrutiny to inform and streamline management of ex-preterm infants at risk of BPD, and potentially improve outcomes.

Opioids and the developing brain: time to rethink perinatal care for infants of opioid-dependent mothers.

Illicit use of opioids is a global health crisis with major implications for women and children. Strategies for managing opioid use disorder (OUD) in pregnancy have been tested over the past 40 years, but studies have focused on maternal and pregnancy outcomes, with less attention given to long-term follow-up of exposed children. Here, we provide a narrative review of recent advances in the assessment and management of neonatal opioid withdrawal syndrome (NOWS), and we summarise evidence from multiple domains-neuroimaging, electrophysiology, visual development and function, neurodevelopment, behaviour, cognition and education-which suggests that prenatal opioid exposure modifies child development. Further studies are required to determine the optimal management of pregnant women with OUD and babies with NOWS. We identify knowledge gaps and suggest that future study designs should evaluate childhood outcomes, including infant brain development and long-term neurocognitive and visual function.

Viability and thresholds for treatment of extremely preterm infants: survey of UK neonatal professionals.

BACKGROUND: Decisions about treatments for extremely preterm infants (EPIs) born in the 'grey zone' of viability can be ethically complex. This 2020 survey aimed to determine views of UK neonatal staff about thresholds for treatment of EPIs given a recently revised national Framework for Practice from the British Association of Perinatal Medicine. METHODS: The online survey requested participants indicate the lowest gestation at which they would be willing to offer active treatment and the highest gestation at which they would withhold active treatment of an EPI at parental request (their lower and upper thresholds). Relative risks were used to compare respondents' views based on profession and neonatal unit designation. Further questions explored respondents' conceptual understanding of viability. RESULTS: 336 respondents included 167 consultants, 127 registrars/fellows and 42 advanced neonatal nurse practitioners (ANNPs). Respondents reported a median grey zone for neonatal resuscitation between 22+1 and 24+0 weeks' gestation. Registrars/fellows were more likely to select a lower threshold at 22+0 weeks compared with consultants (Relative Risk (RR)=1.37 (95% CI 1.07 to 1.74)) and ANNPs (RR=2.68 (95% CI 1.42 to 5.06)). Those working in neonatal intensive care units compared with other units were also more likely to offer active treatment at 22+0 weeks (RR=1.86 (95% CI 1.18 to 2.94)). Most participants understood a fetus/newborn to be 'viable' if it was possible to survive, regardless of disability, with medical interventions accessible to the treating team. CONCLUSION: Compared with previous studies, we found a shift in the reported lower threshold for resuscitation in the UK, with greater acceptance of active treatment for infants <23 weeks' gestation.

Prenatal opioid exposure - Increasing evidence of harm.

Prenatal opioid exposure adversely impacts upon fetal growth and places the newborn at risk of neonatal opioid withdrawal. The severity and duration of opioid withdrawal cannot be predicted in the individual baby and may be contributed to by other drugs including benzodiazepines and alcohol as well as cigarette smoking. Mitigating factors include breastfeeding, rooming in and absence of maternal polypharmacy. Less well recognised are a variety of other complications associated with prenatal opioid exposure including epigenetic changes, effects on neurophysiological function and structural alterations to the developing brain. The visual system is significantly affected, with changes to both clinical and electrophysiological function persisting at least to mid-childhood. Longer term neurodevelopmental and behavioural outcomes are confounded by multiple factors including poverty, parent-child interaction and small study numbers, but systematic reviews consistently demonstrate poorer outcomes for those children and young people prenatally exposed to opioids. Crucially, manifestation of neonatal withdrawal is not a prerequisite for important long term problems including behavioural, emotional or motor function disorder, sensory or speech disorder, strabismus and nystagmus. A body of evidence supports an independent adverse effect of prenatal opioid exposure upon fetal brain development, mediated via a systemic neuro-inflammatory process. Children prenatally exposed to opioids should remain under appropriate follow up, at least until school entry, as difficulties may only become apparent in mid-childhood. Future studies of the management of opioid use disorder in pregnancy, including maintenance methadone, must include longer term outcomes for the baby.

Determining the pattern and prevalence of alcohol consumption in pregnancy by measuring biomarkers in meconium.

OBJECTIVE: To investigate the feasibility of determining the pattern and prevalence of alcohol consumption in pregnancy by measuring ethanol biomarkers in meconium. DESIGN: Population-based observational study. SETTING: Inner-city maternity unit in Scotland, UK. POPULATION: Random sample of singleton infants delivered after 36 completed weeks' gestation. METHODS: Fatty acid ethyl esters (FAEEs) and ethyl glucuronide (EtG) in meconium were measured by liquid chromatography-mass spectroscopy. Samples were frozen at -20°C before analysis. Results were compared anonymously with demographic data including maternal age, parity, smoking, ethnicity and postcode and with infant gestation, birth weight and head circumference. Written informed consent was obtained from all subjects. RESULTS: 235 samples of meconium were analysed (70% of eligible babies). Only four (1%) of mothers declined to participate. FAAEs were detected in all, including four samples below the limit of quantification (10 ng/g). 98 (42%) samples had FAEE concentrations >600 ng/g. EtG was detectable in 93 (40%) samples; in 35 (15%) EtG concentration was >30 ng/g. No mother reported heavy alcohol consumption in pregnancy. FAAE concentration correlated with EtG (Pearson's coefficient; p<0.001). There was no association between either biomarker and maternal age, parity, smoking, ethnicity or postcode, or infant gestation, birth weight or head circumference. CONCLUSION: Measurement of ethanol biomarkers in meconium is a feasible tool for determining the pattern and prevalence of alcohol consumption in pregnancy. Data suggest that at least 15% of pregnant women in the west of Scotland are consuming significant quantities of alcohol during latter pregnancy.

Increased DNA Methylation of ABCB1, CYP2D6, and OPRM1 Genes in Newborn Infants of Methadone-Maintained Opioid-Dependent Mothers.

OBJECTIVE: To investigate whether in utero opioid exposure, which has been linked to adverse neurodevelopmental and social outcomes, is associated with altered DNA methylation of opioid-related genes at birth. STUDY DESIGN: Observational cohort study of 21 healthy methadone-maintained opioid-dependent mother-infant dyads consecutively delivered at >36 weeks of gestation, and 2 comparator groups: smoking, "deprived" opioid-naïve mother-infant dyads (n = 17) and nonsmoking, "affluent" opioid-naïve mother-infant dyads (n = 15). DNA methylation of ABCB1, CYP2D6, and OPRM1 genes for mothers and babies was determined from buccal swabs. Plasma methadone concentrations were additionally measured for methadone-maintained opioid-dependent mothers. RESULTS: DNA methylation for ABCB1 and CYP2D6 was similar in opioid-naïve infants compared with their mothers, but was less for OPRM1 (3 ± 1.6% vs 8 ± 1%, P < .0005). Opioid-exposed newborns had similar DNA methylation to their mothers for all genes studied and greater methylation of ABCB1 (18 ± 4.8% vs 3 ± 0.5%), CYP2D6 (92 ± 1.2% vs 89 ± 2.4%), and OPRM1 (8 ± 0.3% vs 3 ± 1.6%) compared with opioid-naïve newborns (P < .0005 for all 3 genes). Infant DNA methylation was not related to birth weight, length of hospital stay, maternal smoking, dose or plasma concentration of methadone at delivery, or postcode of residence. CONCLUSIONS: In utero exposure to opioids is associated with increased methylation of opioid-related genes in the newborn infant. It is not clear whether these findings are due to opioid exposure per se or other associated lifestyle factors.

Reduced fetal growth in methadone-maintained pregnancies is not fully explained by smoking or socio-economic deprivation.

AIM: To determine if reduced fetal growth in infants of opioid-dependent mothers prescribed methadone maintenance in pregnancy is explained by cigarette smoking or socio-economic deprivation. DESIGN: Retrospective cohort study. SETTING: Inner-city maternity unit in Scotland. PARTICIPANTS: A total of 366 singleton infants of methadone-prescribed opioid-dependent mothers compared with the Scottish birth population (n=103 366) as a whole. MEASUREMENTS: Primary outcome measures were birth weight and head circumference. FINDINGS: In infants of methadone-prescribed opioid-dependent mothers mean birth weight was 259 g [95% confidence interval (CI) 214-303 g; P<0.0001] less, and mean head circumference 1.01 cm (95% CI 0.87-1.15 cm; P<0.0001) less than in controls, allowing for gestation, cigarette smoking, area deprivation, infant sex and maternal age and parity. This represents an adjusted difference of -0.61 (95% CI -0.52--0.71; P<0.0001) Z-score in mean birth weight and -0.77 (95% CI -0.66--0.89; P<0.0001) Z-score in mean head circumference. CONCLUSIONS: Reduced fetal growth in infants of opioid-dependent mothers prescribed methadone maintenance in pregnancy is not fully explained by cigarette smoking, area deprivation, maternal age or parity.

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.

Prevalence and characteristics of rib fractures in ex-preterm infants.

OBJECTIVES: This study aimed to identify the prevalence and characteristics of rib fractures in ex-preterm infants. METHODS: Infants born at <37 weeks' gestation and admitted before 2011 to 3 regional neonatal units were identified from admission registers. For 2 centers, these data were available from 2000 onward and, for another center, from 2005. Electronic records were searched to identify chest radiographs performed up to age 1 year. Chest radiograph reports were then reviewed for evidence of rib fractures, and the case notes of all affected individuals were scrutinized. RESULTS: Of the 3318 eligible preterm infants, 1446 had a total of 9386 chest radiographs. Of these infants, 26 (1.8%) were identified as having a total of 62 rib fractures. Their median (range) gestation at birth was 26 weeks (23-34). The median chronological age of these infants at the time of the radiograph was 14 weeks (5 weeks to 8 months). The median corrected gestational age at the time of the radiograph was 39 weeks (34 weeks to 4 months). Of the 62 fractures, 27 (36%) were sited posteriorly, and 15 (53%) of the infants with posterior rib fractures were diagnosed with osteopathy of prematurity. Classic risk including conjugated hyperbilirubinemia and diuretics, were present in 23 of 26 (88%) infants. A full skeletal survey was performed in 8 of 26 (31%). Investigations for nonaccidental injury occurred in 4 of 26 (15%) cases. CONCLUSIONS: Evidence of rib fractures is present in ~2% of ex-preterm infants. The evaluation of these fractures in infancy requires a detailed neonatal history irrespective of the site of rib fracture.

The management of heroin misuse in pregnancy: time for a rethink?

Heroin use in pregnancy is a worldwide problem. Methadone maintenance treatment has definite advantages for the mother and is currently recommended in the UK. There is, however, increasing evidence of adverse effects upon developing cortical and visual function in children of treated heroin-addicted mothers. The longer-term implications of this are not yet clear, and are confounded by poly-drug misuse and ongoing social deprivation. There is a paucity of evidence regarding outcome for infants who require pharmacological treatment for neonatal abstinence syndrome compared to those who have only mild symptoms. Well-controlled studies of the treatment of heroin misuse in pregnancy that take account of both neonatal and longer term outcomes for the child are urgently required.

Progesterone for the prevention of preterm birth in twin pregnancy (STOPPIT): a randomised, double-blind, placebo-controlled study and meta-analysis.

BACKGROUND: Women with twin pregnancy are at high risk for spontaneous preterm delivery. Progesterone seems to be effective in reducing preterm birth in selected high-risk singleton pregnancies, albeit with no significant reduction in perinatal mortality and little evidence of neonatal benefit. We investigated the use of progesterone for prevention of preterm birth in twin pregnancy. METHODS: In this double-blind, placebo-controlled trial, 500 women with twin pregnancy were recruited from nine UK National Health Service clinics specialising in the management of twin pregnancy. Women were randomised, by permuted blocks of randomly mixed sizes, either to daily vaginal progesterone gel 90 mg (n=250) or to placebo gel (n=250) for 10 weeks from 24 weeks' gestation. All study personnel and participants were masked to treatment assignment for the duration of the study. The primary outcome was delivery or intrauterine death before 34 weeks' gestation. Analysis was by intention to treat. Additionally we undertook a meta-analysis of published and unpublished data to establish the efficacy of progesterone in prevention of early (<34 weeks' gestation) preterm birth or intrauterine death in women with twin pregnancy. This study is registered, number ISRCTN35782581. FINDINGS: Three participants in each group were lost to follow-up, leaving 247 analysed per group. The combined proportion of intrauterine death or delivery before 34 weeks of pregnancy was 24.7% (61/247) in the progesterone group and 19.4% (48/247) in the placebo group (odds ratio [OR] 1.36, 95% CI 0.89-2.09; p=0.16). The rate of adverse events did not differ between the two groups. The meta-analysis confirmed that progesterone does not prevent early preterm birth in women with twin pregnancy (pooled OR 1.16, 95% CI 0.89-1.51). INTERPRETATION: Progesterone, administered vaginally, does not prevent preterm birth in women with twin pregnancy. FUNDING: Chief Scientist Office of the Scottish Government Health Directorate.

Maturation of rod function in preterm infants with and without retinopathy of prematurity.

OBJECTIVES: To establish normal development of rod electroretinograms in preterm infants and to assess the effects of retinopathy of prematurity (ROP). STUDY DESIGN: We measured 88 Naka-Rushton functions from 41 preterm infants at maturities from 30 to 72 weeks postmenstrual age (PMA). Outcomes (log sigma, retinal sensitivity and V(max), retinal responsivity) were compared between control (no ROP), untreated ROP, and treated ROP. RESULTS: In control infants, sensitivity increased by 1.5 log units from 30 to 40 weeks PMA and by a further 0.5 log units by 50 weeks PMA but was 0.5 log units less than in similarly-mature, healthy, term-born infants. Average retinal responsivity increased from 23 microV to 90 microV between 30 and 40 weeks PMA and was 35 muV greater at 40 weeks PMA than in similarly-mature term-born infants. At around 36 weeks PMA, (when onset of ROP peaks), infants with untreated ROP had average retinal sensitivity 0.2 log units lower than control infants; sensitivity was reduced further in infants treated for ROP. Retinal responsiveness did not differ between control subjects and untreated infants with ROP but was greatly reduced in infants treated for ROP. CONCLUSIONS: Maturation of rod sensitivity appears to be slowed by preterm birth whereas maturation of rod responsivity is accelerated. ROP reduces retinal sensitivity, and treated ROP reduces both sensitivity and responsivity.