Pregnant Women

pregnant
Background:
The prevalence and determinants of medication use in pregnancy have not been described in an Irish setting. Drug utilisation studies in pregnancy are important to focus research on the most commonly used medications that have potential for foetal harm. In the same way prevalence, predictors and perinatal outcomes associated with peri-conceptional alcohol consumption is poorly described in populations of pregnant Irish women, and the impact on foetal harm controversial. We aim to assess the prevalence, predictors and perinatal outcomes for medications taken during pregnancy and the impact of alcohol in the peri-conceptual period.
Lastly, we will focus on a particularly vulnerable group of pregnant women- those who are taking methadone during their pregnancy as part of a harm minimisation programme in opioid-dependent pregnant women.
Methadone’s benefits are likely to outweigh any risks posed by treatment as it reduces the harm of continued illicit drug use in pregnancy and facilitates appropriate engagement with addiction and antenatal services. However, methadone use in pregnancy has been associated with adverse perinatal outcomes including preterm birth and low birth weight. Neonatal abstinence syndrome (NAS) is a common adverse effect of methadone use in pregnancy, occurring in 45-97% of exposed neonates. The determinants of NAS are still poorly understood.

Study Aims: This research programme aims to describe current use of medications in pregnancy in an Irish setting using pharmacoepidemiological techniques. Further studies will then focus on perinatal outcomes after exposure to a commonly used medication with potential for foetal harm. Studies will examine exposures and perinatal outcomes in a large cohort of women who had a baby in the Coombe Women and Infant’s University Hospital between 2000 and 2007.

Study Objectives:

  1. Determine the prevalence of medication use in early pregnancy among a large Irish obstetric cohort, exploring the use of medications with potential for foetal harm, prescribing for women with chronic medical disorders and the determinants of medication use.
    - Study Design: retrospective cohort study using electronic hospital records. We reviewed early pregnancy medication use, as reported to a midwife at the booking interview, in women delivering between 2000 and 2007 in a large maternity hospital in Dublin, Ireland (n=61,252).
    - Progress to date: This study is now complete and a paper has been published (Cleary et al. 2010).
  2. To determine the prevalence, predictors and perinatal outcomes associated with peri-conceptional alcohol consumption.
    - Study Design: A cohort study of 61,241 women delivering in a large urban maternity hospital. Self-reported alcohol consumption at the booking visit was categorised as low (0-5 units per week), moderate (6-20 units per week) and high (> 20 units per week).
    - Progress to date: This study is now complete and has been published (Mulally et al. 2011).
  3. To determine if there is a relationship between maternal methadone dose in pregnancy and the incidence of neonatal abstinence syndrome (NAS).
    - Study Design: Systematic review.
    - Progress to date: This study is complete and has been published by the journal Addiction (Cleary et al. 2010).
  4. To examine the impact of methadone exposure in pregnancy on perinatal outcomes and NAS
    - Study Design: Retrospective cohort study using electronic hospital records. Perinatal outcomes were compared for 618 methadone-exposed pregnancies and 60412 non methadone-exposed pregnancies. The determinants of NAS were explored within the methadone-exposed group
    - Progress to date: This retrospective cohort study is complete and a paper has been published (Cleary et al. 2011).
  5. To examine the impact of methadone exposure in pregnancy on perinatal outcomes and NAS.
    - Study Design: Prospective, multicentre cohort study. Opioid-dependent pregnant women on methadone are being recruited from two Dublin Maternity Hospitals
    -Progress to date: This study is now complete and a paper has been published (Cleary et al. 2012).
  6. To examine methadone dosing and prescribed medication use in a cohort of opioid dependent pregnant women.
    -Study Design: Prospective, multicentre cohort study.
    -Progress to date: This study is complete and a paper has been published in the journal Addiction (Cleary et al. 2013).
  7. To examine the prevalence of prescribing in pregnancy using the Irish Primary Care Research Network.
    - Study Design: Retrospective review of electronic healthcare records routinely collected in primary care, of pregnant women attending nine Dublin-based General Practices affiliated to the Irish Primary Care Research Network (IPCRN) for antenatal care between January 2007 and October 2013
    -Progress to date: This study is now complete and a paper has been submitted for publication.