Transcript Metformin and Polycystic Ovary Syndrome

The Impact of Methadone
Maintenance Treatment
During Pregnancy on
Perinatal Outcomes
Cleary BJ, Donnelly J, Strawbridge J, Gallagher PJ, Fahey T, Murphy
DJ.
Brian J Cleary
HRB PhD Scholar, Health Services Research
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
• Based on electronic records of 61043 singleton
pregnancies delivered Jan 2000 and Dec 2007
• Methadone exposure recorded prospectively by a
midwife during pregnancy before perinatal outcomes
known
– At booking interview
– At admission to delivery suite if unbooked
• Other sources of ascertainment:
– Controlled drug registers
– Hospital prescription records
• Research protocol approved by CWIUH REC
Methods
Main Study Variables
• Maternal sociodemographic, medical
and obstetric characteristics
• Methadone dose at delivery
• Perinatal outcomes
• Objective NAS diagnosis- modified
Finnegan scoring system
Methods
Statistical Analysis
Univariable and multivariable logistic
regression used to determine crude and
adjusted odds ratios and 95% confidence
intervals for the association between:
– methadone exposure and maternal characteristics
– methadone exposure and maternal/perinatal
outcomes
– methadone dose and occurrence of NAS
Results
Maternal Characteristics
• Methadone was used at delivery in 618 (1%) pregnancies
• Methadone use at delivery was more likely in women who
were:
–
–
–
–
–
–
–
–
–
–
Younger
Unemployed or manual workers
Irish
Non-married
Multiparous
Had an unplanned pregnancy
Late bookers
Public patients
Smokers
Heavy drinkers (>14 units/week)
Results
Perinatal Outcomes
• Methadone use was associated with
adverse perinatal outcomes:
– Preterm birth (<37 weeks)
– Small for gestational age (<10th centile)
– Admission to neonatal unit
– Congenital abnormality
Results
Neonatal 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
0
20
40
60
80
100
Incidence of NAS by Methadone Dose Band at Delivery
<=20mg
21-50mg
51-80mg
81-100mg
Methadone Dose at Delivery
>100mg
Incidence of NAS by Methadone Dose Band at Delivery
0
20
40
60
80
100
Excluding Neonates with Positive Urine Toxicology
<=20mg
21-50mg
51-80mg
81-100mg
Methadone Dose at Delivery
>100mg
Methadone Dose at Delivery
No NAS
NAS
150
100
50
0
Mean (SD)
Mean (SD)
50.04mg (24.44)
62.51mg (26.29)
Independent samples T-Test p<0.001
Limitations
• Retrospective study from one centre
• Unblinded assessment of NAS
• No indication of severity/duration of
NAS available
• Maternal urine toxicology results not
available
Implications
• Further interventions required to address
adverse perinatal outcomes in methadoneexposed pregnancies
• Useful information for patient counselling
• Robust prospective studies required to
confirm dose response effect
• Future studies need further objective data on
concomitant drug exposures
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
Thank You !