Drug use in pregnancy in Ireland's capital city: A decade of trends and outcomes.

OBJECTIVE: The aim of this study was to present contemporary trends in opiate use disorder (OUD) and substance use in pregnancy in Ireland, with associated obstetric outcomes, over the last ten years. STUDY DESIGN: This retrospective observational cohort study was conducted at an Irish tertiary maternity unit. All women with OUD or substance use in pregnancy delivered under this service between 2010 and 2019 were included. Drug-exposure was self-reported. Data was collected by combining electronic and hand-held patient records. Trends and outcomes were analysed by year of delivery. Approval for the study was granted by the institution's clinical governance committee. RESULTS: Of the 82,669 women delivered, 525 had OUD or substance use in pregnancy (1 in every 160 women booking). 11.6% were homeless, 20.0% were in full-time employment and 91.0% smoked tobacco in pregnancy. 66.3% had a history of psychiatric disorders. Over the ten years, there was a significant reduction in women delivered with OUD or substance use in pregnancy (0.8 % to 0.4 %, RR 0.55, 95 % CI 0.36-0.85), significant reduction in the proportion of women on Opioid-Substitute-Treatment (OST, RR 0.66 95 % CI 0.51-0.87) and an increase in mean maternal age (30.7to32.0 years). Rates of cocaine and cannabis consumption increased (20.6 %, RR 3.8, 95 % CI 1.57-9.44: 24.0 %, RR 3.7, 95 % CI 1.58-8.86 respectively). The maternal mortality rate was 380.9:100,000 births. The perinatal mortality rate was 15.6:1000 births. The preterm birth rate was 17.9 %, with a mean birth weight of 2832 g. The rate of NICU admission was 52.0 % and the mean length of stay was 22.4 days. Amongst the smaller OUD population, the rate of NICU admission for Neonatal Abstinence Syndrome (NAS) and treatment for NAS increased over the study timeframe (36.0 %, RR 2.97, 95 % CI 1.86-4.75: 28.5 %, RR 2.92, 95 % CI 1.70-5.0 respectively). CONCLUSIONS: The obstetric population attending an Irish antenatal service with opiate use disorder or substance exposure is reducing in size with older patients, less opioid substitute therapy and increasing cocaine and cannabis use. These women have high rates of maternal and perinatal morbidity and mortality. Specialist antenatal addiction services, coordinated by the drug-liaison midwife, are critical in adapting care to respond to this dynamic and vulnerable patient cohort.

Methadone dosing and prescribed medication use in a prospective cohort of opioid-dependent pregnant women.

AIMS: This study aimed to (i) describe methadone dosing before, during and after pregnancy, (ii) to compare the incidence of neonatal abstinence syndrome (NAS) between those with dose decreases and those with steady or increasing doses and (iii) to describe prescribed medication use among opioid-dependent pregnant women. DESIGN: Prospective cohort study. SETTING: Two Irish tertiary care maternity hospitals. PARTICIPANTS: A total of 117 pregnant women on methadone maintenance treatment (MMT) recruited between July 2009 and July 2010. MEASUREMENTS: Electronic dispensing records from addiction clinics and the Primary Care Reimbursement Service were used to determine methadone doses and dispensed medications in the year preceding and the month following delivery. The Finnegan score was used to determine need for medical treatment of NAS. FINDINGS: Of the 117 participants, sufficient dosing data were available for 89 women treated with MMT throughout pregnancy; 36 (40.4%) had their dose decreased from a mean pre-pregnancy dose of 73.3 mg [standard deviation (SD) 25.5] to a third-trimester dose of 58.0 mg (SD 26.0). The corresponding figures for those with increased doses (n = 31, 34.8%) were 70.7 mg (SD 25.3) and 89.7 mg (SD 21.0), respectively. The incidence of medically treated NAS did not differ between dosage groups. Antidepressants were dispensed for 29 women (25.7%) during pregnancy, with the rate decreasing from pre-pregnancy to postpartum. Benzodiazepines were prescribed for 43 women (38.0%). CONCLUSION: In the Irish health service, opioid-dependent women frequently have their methadone dose decreased during pregnancy but this does not appear to affect the incidence of the neonatal abstinence syndrome in their babies.

Methadone and perinatal outcomes: a prospective cohort study.

AIMS: Methadone use in pregnancy has been associated with adverse perinatal outcomes and neonatal abstinence syndrome (NAS). This study aimed to examine perinatal outcomes and NAS in relation to (i) concomitant drug use and (ii) methadone dose. DESIGN: Prospective cohort study. SETTING: Two tertiary care maternity hospitals. PARTICIPANTS: A total of 117 pregnant women on methadone maintenance treatment recruited between July 2009 and July 2010. MEASUREMENTS: Information on concomitant drug use was recorded with the Addiction Severity Index. Perinatal outcomes included pre-term birth (<37 weeks' gestation), small-for-gestational-age (<10th centile) and neonatal unit admission. NAS outcomes included: incidence of medically treated NAS, peak Finnegan score, cumulative dose of NAS treatment and duration of hospitalization. FINDINGS: Of the 114 liveborn infants 11 (9.6%) were born pre-term, 49 (42.9%) were small-for-gestational-age, 56 (49.1%) had a neonatal unit admission and 29 (25.4%) were treated medically for NAS. Neonates exposed to methadone-only had a shorter hospitalization than those exposed to methadone and concomitant drugs (median 5.0 days versus 6.0 days, P = 0.03). Neonates exposed to methadone doses ≥80 mg required higher cumulative doses of morphine treatment for NAS (median 13.2 mg versus 19.3 mg, P = 0.03). The incidence and duration of NAS did not differ between the two dosage groups. CONCLUSIONS: The incidence and duration of the neonatal abstinence syndrome is not associated with maternal methadone dose, but maternal opiate, benzodiazepine or cocaine use is associated with longer neonatal hospitalization.