170 likes | 354 Views
Methadone Maintenance Treatment During Pregnancy and Perinatal Outcomes. Cleary BJ 1,2,3 ; DONNELLY JM 2 ; STRAWBRIDGE JD 3 ; GALLAGHER PJ 3 ; FAHEY T 4 ; WHITE MJ 2 ; MURPHY DJ 1,2 1 Department of Obstetrics and Gynaecology, Trinity College Dublin
E N D
Methadone Maintenance Treatment During Pregnancy and Perinatal Outcomes Cleary BJ1,2,3; DONNELLY JM2; STRAWBRIDGE JD3; GALLAGHER PJ3; FAHEY T4; WHITE MJ2; MURPHY DJ1,2 1Department of Obstetrics and Gynaecology, Trinity College Dublin 2Coombe Women and Infants University Hospital, Dublin 8 3School of Pharmacy, Royal College of Surgeons in Ireland, 123 St Stephen’s Green, Dublin 2 4HRB Centre for Primary Care Research, Royal College of Surgeons in Ireland, 123 St Stephen’s Green, Dublin 2
Disclosure Statement • None of the study authors have any conflicts of interest to declare • This research was funded by an unrestricted educational grant from the charity Friends of the Coombe and the School of Pharmacy, Royal College of Surgeons in Ireland
Background • Methadone maintenance- current treatment of choice for pregnant opiate-dependent women • Few studies have compared perinatal outcomes in methadone-exposed and non-exposed pregnancies • Neonatal abstinence syndrome (NAS) develops in 40-90% of neonates exposed to methadone in utero • Results of studies of relationship between methadone dose and NAS have been equivocal
Aims • Compare the likelihood of adverse perinatal outcomes in methadone exposed and unexposed pregnancies • Explore the determinants of the occurence of neonatal abstinence syndrome (NAS) in methadone-exposed neonates
Methods • Retrospective cohort study • Based on electronic records of 61043 singleton pregnancies delivered Jan 2000 and Dec 2007 • Methadone exposure at delivery • Exposure recorded by a midwife during pregnancy before perinatal outcomes known • At booking interview • At admission to delivery suite if unbooked • Other sources of exposure ascertainment: • Controlled drug registers • Hospital prescription records • Research protocol approved by REC
MethodsMain Study Variables & Outcomes • Maternal sociodemographic, medical and obstetric characteristics • Methadone dose at delivery • Perinatal outcomes • Congenital anomalies- EUROCAT classification • NAS diagnosis- objective scoring system (Finnegan)
MethodsStatistical Analysis • Univariable and multivariable logistic regression • Odds ratios and 95% confidence intervals for the association between: • methadone exposure and maternal/perinatal outcomes • adjusted for differences in maternal characteristics between exposed and unexposed • risk factors and the occurrence of NAS • adjusted for neonatal and maternal characteristics that differ between NAS and non-NAS groups • Mixed effects logistic regression used to adjust for lack of independence in perinatal outcomes
ResultsMaternal Characteristics • Methadone used at delivery in 618 (1%) pregnancies • Factors associated with methadone use: • Age 20-29y • Unemployment OR 15.4,95% CI 11.2-21.1 • Irish nationality OR 4.7, 95% CI 3.3-6.8 • Single marital status OR 42.5,95% CI 28.7-62.9 • Unplanned pregnancy OR 4.6, 95% CI 3.8-5.4 • Public patient OR 209, 95% CI 29-1485 • Smoking in pregnancy OR 53.1, 95% CI 38.2-73.8 • Hepatitis C and HIV more common in methadone-exposed
ResultsPerinatal Outcomes • Methadone exposure associated with adverse perinatal outcomes: • Preterm birth (<37/40) aOR 3.1, 95% CI 2.3-4.1 • Very preterm birth (<32/40) aOR 2.5, 95% CI 1.4-4.3 • SGA (<10th centile) aOR 2.2, 95% CI 1.8-2.6 • Apgar score <3 (1 min.) aOR 1.9, 95% CI 1.1-3.4 • Apgar score <7 (5 min.) aOR 2.1, 95% CI 1.2-3.5 • Neonatal unit admission aOR 6.2, 95% CI 5.1-7.4 • Perinatal death: 2.4% (15/618) vs. 0.8% (491/60412)
ResultsPerinatal Outcomes Major Anomalies Categorised Into EUROCAT Subgroups * Includes Pierre Robin Sequence
ResultsPerinatal Outcomes • Pierre Robin Sequence • Exposed: 4 cases in 618 (1 in 155) • Non-exposed: 8 cases in 60412 (1 in 7,552) • Methadone exposure associated with major congenital anomalies: • aOR1.9, 95% CI 1.1-3.4
ResultsNeonatal Abstinence Syndrome • A diagnosis of NAS was recorded for 236 (40.1%) methadone exposed neonates • NAS was more likely with increasing methadone dose at delivery • >50mg vs. ≤50mg aOR2.1, 95%CI 1.5-3.0
Limitations • Retrospective study using routinely collected data from one centre • Residual confounding may explain some of adverse perinatal outcomes • Incomplete ascertainment of congenital anomalies • Unblinded assessment of NAS • Maternal urine toxicology results not available
Implications • Dedicated, well-resourced, multi-disciplinary care required for these women & their infants as they are at increased risk of very preterm birth, low Apgar scores and other adverse perinatal outcomes • Findings relating to congenital malformations need to be evaluated in other populations • Robust prospective studies of large cohorts of opioid-dependent pregnant women required to assess all the determinants of NAS and provide further information on perinatal and longer-term outcomes
Acknowledgements Thanks to: • Funders • Friends of the Coombe • School of Pharmacy, RCSI • Supervisors • Midwives and other staff who collected the data • Emma McNamee who extracted the data