(SLA-007) Trends of Antidepressants Use During Pregnancy: a Nationwide Cohort Study

Background: Clinical guidelines recommend that women with severe depressive symptoms continue pharmacological therapy during pregnancy and adhere to antidepressants (ADs) that stabilize their condition. As the prevalence of depression rises, it is important to evaluate whether their prescription patterns of ADs in the real-world align with guidelines.

Objectives: To examine the prescription patterns of ADs during pregnancy and their temporal trends among women with depression in South Korea.

Methods: This study was performed using Korea’s claims database. We identified women who delivered between 2010 and 2021, had been diagnosed with depression and received ≥2 prescriptions of ADs within 6 months before pregnancy (last menstrual period [LMP]). Then, we defined pregnancy-related periods as follows: 1) pre-pregnancy and pregnancy recognition period (LMP – 180 to LMP + 45 days), 2) late first trimester (LMP + 46 to LMP + 90 days), 3) second/third trimester (LMP + 91 to delivery date – 1 day), and 4) post-pregnancy period (delivery date to delivery date + 180 days). Exposure during each period was defined as having at least one AD prescription within the respective period. Continuation, discontinuation, and re-initiation during pregnancy were determined based on these exposure statuses in the late first trimester and the second/third trimester periods. Switching was defined as a change in the prescribed ADs during pregnancy after restricting the cohort to those with ≥2 prescriptions for the same ADs before LMP. Lastly, we evaluated temporal trends by calculating rates for each pattern in three-year intervals and analyzed the frequency of switching patterns for each medication.

Results: Among 12,635 pregnancies with depression, 10,198 (80.7%) discontinued their use of ADs during pregnancy, with discontinuation rates remaining consistently high, ranging from 82.0% (2010-2012) to 81.3% (2019-2021) over time. Conversely, continuation, re-initiation or switching rates were low (13.0% to 13.6%; 4.9% to 5.1%; 3.15% to 3.21%, respectively) during the study timeframe. Among all observed switchers (n=332), escitalopram was the most preferred alternative (n=104, 31.3%), followed by sertraline and fluoxetine. The most common switching pattern was from paroxetine to escitalopram (n=28, 8.4%).

Conclusions: Continuation rates of AD during pregnancy remained consistently low throughout the study period, contrary to guideline recommendations. However, the preference for escitalopram and sertraline as the most commonly switched-to ADs aligned with existing recommendations, providing reassurance that, when switching occurs, it generally follows evidence-based guidelines that prioritize the safety of fetus.