Importance Becoming a first-time parent is a major life-changing event and can be challenging regardless of the pregnancy outcome. However, little is known how different adverse pregnancy outcomes affect the father’s risk of psychiatric treatment post partum.

Objective To examine the associations of adverse pregnancy outcomes with first-time psychiatric treatment in first-time fathers.

Design, Setting, and Participants This nationwide cohort study covered January 1, 2008, to December 31, 2017, with a 1-year follow-up completed December 31, 2018. Data were gathered from Danish, nationwide registers. Participants included first-time fathers with no history of psychiatric treatment. Data were analyzed from August 1, 2022, to February 20, 2024.

Exposures Adverse pregnancy outcomes including induced abortion, spontaneous abortion, stillbirth, small for gestational age (SGA) and not preterm, preterm with or without SGA, minor congenital malformation, major congenital malformation, and congenital malformation combined with SGA or preterm compared with a full-term healthy offspring.

Main Outcomes and Measures Prescription of psychotropic drugs, nonpharmacological psychiatric treatment, or having a psychiatric hospital contact up to 1 year after the end of the pregnancy.

Results Of the 192 455 fathers included (median age, 30.0 [IQR, 27.0-34.0] years), 31.1% experienced an adverse pregnancy outcome. Most of the fathers in the study had a vocational educational level (37.1%). Fathers experiencing a stillbirth had a significantly increased risk of initiating nonpharmacological psychiatric treatment (adjusted hazard ratio [AHR], 23.10 [95% CI, 18.30-29.20]) and treatment with hypnotics (AHR, 9.08 [95% CI, 5.52-14.90]). Moreover, fathers experiencing an early induced abortion (≤12 wk) had an increased risk of initiating treatment with hypnotics (AHR, 1.74 [95% CI, 1.33-2.29]) and anxiolytics (AHR, 1.79 [95% CI, 1.18-2.73]). Additionally, late induced abortion (>12 wk) (AHR, 4.46 [95% CI, 3.13-6.38]) and major congenital malformation (AHR, 1.36 [95% CI, 1.05-1.74]) were associated with increased risk of nonpharmacological treatment. In contrast, fathers having an offspring being born preterm, SGA, or with a minor congenital malformation did not have a significantly increased risk of any of the outcomes.

Conclusions and Relevance The findings of this Danish cohort study suggest that first-time fathers who experience stillbirths or induced abortions or having an offspring with major congenital malformation had an increased risk of initiating pharmacological or nonpharmacological psychiatric treatment. These findings further suggest a need for increased awareness around the psychological state of fathers following the experience of adverse pregnancy outcomes.