Importance: Topical corticosteroids are frequently used during pregnancy. Limited data have raised concerns about an increased risk of the newborn being small for gestational age (SGA) and having low birth weight, in particular with use of potent to very potent agents during pregnancy. Objective: To evaluate whether topical corticosteroid use in pregnancy is associated with increased risks of SGA and low birth weight. Design, Setting, and Participants: From a source cohort of 1.1 million pregnancies with individual-level informed data from various registries, this nationwide cohort study identified topical corticosteroid-exposed pregnancies in Denmark from January 1, 1997, to December 31, 2016, for a total of 60497, that were matched with 241986 unexposed pregnancies on the basis of propensity scores, including a wide set of baseline characteristics. Data analysis was performed from September 8, 2020, to February 23, 2021. Exposures: Filled prescriptions for topical corticosteroids during pregnancy. Main Outcomes and Measures: Primary outcomes were SGA and low birth weight. Association between outcomes and exposure was assessed by relative risk ratios (RRs) and absolute risk differences (ARDs). Results: Among the 60497 matched pregnancies exposed to topical corticosteroids, 5678 (9.4%) of the delivered infants were born SGA compared with 22634 infants (9.4%) among the matched unexposed pregnancies (RR, 1.00; 95% CI, 0.98-1.03 and ARD, 0.3; 95% CI, -2.3 to 2.9 per 1000 pregnancies). Low birth weight occurred in 2006 (3.3%) of the exposed pregnancies compared with 8675 (3.6%) of the unexposed pregnancies (RR, 0.92; 95% CI, 0.88-0.97 and ARD, -2.7; 95% CI, -4.3 to -1.1 per 1000 pregnancies). Exposure to potent to very potent topical corticosteroids at any amount was not associated with an increased risk of SGA (RR, 1.03; 95% CI, 0.99-1.07) or low birth weight (RR, 0.94; 95% CI, 0.88-1.00). Post hoc analyses did not find a significant increased risk among those receiving large amounts of potent to very potent topical corticosteroids (ie, >200 g throughout pregnancy) compared with unexposed pregnancies (RR, 1.17; 95% CI, 0.95-1.46 for SGA and RR 1.14; 95% CI, 0.81-1.60 for low birth weight). Conclusions and Relevance: This large cohort study found no association between topical corticosteroid use in pregnancy and an increased risk of SGA or low birth weight. These results suggest that a moderate to large increase in the risk is unlikely, even when large amounts of potent to very potent topical corticosteroids are used in pregnancy..