A study of an obstetric addiction clinic has found that opioid addiction has declined significantly in recent years, however other addictions have increased.

Drug and alcohol use during pregnancy is a problem worldwide and the consequences can be far reaching. Infants born to mothers who misuse substances during pregnancy face an increased risk of prematurity, low birth weight, behavioural issues and learning difficulties.

Pregnant addicts may not engage with healthcare, with some only presenting when they are already very far into the pregnancy. In an attempt to tackle this, drug liaison midwives (DLM) were appointed to Dublin’s three maternity hospitals in 1999.

There are a number of ways women can avail of this service, including self-referral, referral by a GP, or referral by community addiction services. At the Rotunda Maternity Hospital, this care is provided by the DOVE Clinic.

This study carried out a review of attendances at DOVE over the 10-year period, 2009-2018, and compared these to the general population.

It found that attendance at the clinic remained stable over the 10-year period - around 12 per 1,000 births. During this time, the number of women presenting with opioid addiction fell significantly. The number of women who began opioid substitution treatment (OST) for the first time in pregnancy, also fell in more recent years.

However, the number of women presenting with non-opioid addiction increased significantly during the study period. This included addiction to alcohol, benzodiazepines, cannabis, cocaine and over-the-counter analgesics.

Meanwhile, the study also found that the number of addicted women attending the DOVE clinic, who were also positive for HIV, hepatitis B, or hepatitis C, also fell significantly over the period.

When it came to labour outcomes, those attending the DOVE clinic were much more likely (62%) to have an unassisted vaginal birth compared to the general population. Instrumental delivery rates were also much lower in this population, while Caesarean rates were similar to the general population.

Women with addiction were much more likely to give birth before 37 weeks’ gestation (17%) compared to the general population (7%). They were also much more likely to have a baby that weighed less than 2.5kg (26% verses 7%).

The infants of addicted mothers were also more likely to require NICU admission compared to infants in the general population.

The researchers highlighted the key role of the DLM, but also warned about the increased risks around prematurity and growth restriction in relation to these infants.

“It is important that this data is used for professional development of staff involved in the provision of care for this vulnerable group, in order to enhance care and reduce stigma,” they said.

Details of these finding are published in the Irish Medical Journal.