Sociodemographic variation in prescriptions dispensed in early pregnancy in Northern Ireland 2010-2016.

Aim: To establish the prevalence of prescriptions dispensed in early pregnancy by maternal age and area deprivation, for women who gave birth in Northern Ireland (NI) 2011-2016.

Study Design: Population-based linked cohort study.

Methods: The NI Maternity System (NIMATS) database was used to identify all births to resident mothers in NI between 2011 and 2016. Prescriptions dispensed between the last menstrual period (LMP) and the first antenatal care visit (mean 10.7 weeks) (2010-2016) were extracted from the Enhanced Prescribing Database (EPD) which records all prescriptions dispensed by pharmacists in NI. EPD data were linked to NIMATS using the mother's Health and Care Number. Maternal deprivation based on the NI Multiple Deprivation Measure 2017 was linked using the mother's postcode.

Results: The cohort included 139,687 pregnancies resulting in live or stillbirths to 106,206 women. A medication was dispensed in 63.5% of pregnancies, and in 48.7% of pregnancies excluding supplements (vitamins, iron, and folic acid). Folic acid was the most commonly dispensed medication (33.1%). Excluding supplements, the mean number of medications was 1.1, with 4.2% having ≥5 medications. The most common non-supplement medications were antibiotics (13.1%), antiemetics (8.7%), analgesics (6.9%), hormonal medications (6.9%) and antidepressants (6.1%). Younger women (<20 years) had more antibiotics while older women (40+ years) had more antidepressants, cardiovascular, antihypertensives, anticoagulant medications and thyroxine. The proportion of women living in the most deprived areas with prescriptions for antidepressants, sedatives, tranquilisers, analgesics, and anti-epileptic medications was double the proportion of women with these medications in the least deprived areas.

Conclusion: Half of all pregnant women in NI were dispensed a non-supplement medication between LMP and the first antenatal care visit. Younger and older mothers and those living in the most deprived areas were more likely to have medications dispensed. More antidepressants were dispensed in areas of social deprivation.