Abstract

Introduction and Objective Given the recent increase in the prescription and dispensation of gabapentinoids (gabapentin and pregabalin) and the importance of controlling for underlying maternal illnesses in drug safety studies, we aimed to develop algorithms for identifying maternal conditions leading to gabapentinoid prescribing among pregnant women using data from six electronic healthcare data sources across Europe. Methods The study was conducted in Finland, France (Haute-Garonne), Italy (Emilia Romagna), Norway, Spain (Valencian region), and Wales (UK), covering three million pregnancies from 2006 to 2020. Algorithms were developed to detect epilepsy, neuropathic pain, and generalized anxiety disorder (GAD) (approved indications for gabapentinoids by the European Medicines Agency, with the exception of gabapentin for GAD) using data ± 1 year around the gabapentinoid prescription date. Data included prescriber specialty, primary and specialized health care diagnoses, and co-prescription/dispensation data. Additional analyses investigated potential unlicensed indications (such as fibromyalgia, restless legs syndrome, bipolar disorder) and potential for abuse (using codes for substance use disorders and alcohol withdrawal). Results Gabapentinoids were prescribed/dispensed in 1770 pregnancies (7.7 per 1000) in Spain, 2912 pregnancies (6.6 per 1000) in Wales, 3163 pregnancies (3.6 per 1000) in Norway, 2406 pregnancies (3.0 per 1000) in Finland, 908 pregnancies (2.2 per 1000) in Italy, and 269 pregnancies (1.9 per 1000) in France. A maternal condition related to gabapentinoid prescriptions was identified by the algorithm in 2797 (88.4%) in Norway, 2180 (74.9%) in Wales, 1269 (71.7%) in Spain, 1534 (63.8%) in Finland, 163 (60.6%) in France, and 396 (43.6%) pregnancies in Italy. Anxiety (licensed or unlicensed) was the most commonly captured condition in Wales (70.5%), Spain (51.5%), Finland (42.0%), and Italy (26.2%), whereas neuropathic pain prevailed in Norway (76.9%) and France (49.8%). Epilepsy was the least frequent maternal condition leading to gabapentinoid prescriptions across all data sources (below 15% of all pregnancies). The relative preponderance of these conditions differed between pregabalin and gabapentin. Additionally, unlicensed indications were captured in 0% to 13% of pregnancies, depending on the data source. The analyses of potential for abuse showed that records of alcohol withdrawal and/or substance use disorders (within 1 year before and after the gabapentinoids prescription/dispensation date) were present in 3% of pregnancies in Italy and up to 23% in Wales. Conclusions Our study provides valuable insights into gabapentinoid use during pregnancy, with anxiety being the most common condition among pregnant women with gabapentinoid prescriptions in Finland, Italy, Spain, and Wales, whereas neuropathic pain predominated in France and Norway. Moreover, we found that between 3 and 23% of these pregnancies were associated with substance abuse, underscoring the need for careful prescribing of commonly abused medicines. The proposed methods for detecting maternal conditions leading to prescribing will facilitate accurate assessment of medication use and safety during pregnancy, whilst addressing confounding by indication.