Abstract: 【Abstract】 Objective To investigate the efficacy and safety of omalizumab in the treatment of chronic spontaneous urticaria （CSU） during pregnancy and lactation. Methods A single-center retrospective study was conducted. From February 2022 to December 2024, 8 pregnant or lactating patients with CSU who received omalizumab treatment were collected from the Departments of Dermatovenereology and Allergy, Tianjin Medical University General Hospital, including 3 pregnant and 5 lactating patients. Clinical data were analyzed, including the patients′ ages, disease duration of CSU, timing of omalizumab initiation, dosage and treatment intervals of omalizumab. During the treatment and follow-up, the 7-day urticaria activity score （UAS7） was used to evaluate disease activity of CSU patients, and adverse events were recorded. Results The ages of the 8 patients ranged from 29 to 40 （33.25 ± 3.81） years, and the disease duration of CSU （M ［Q1, Q3］） was 2.8 （1.6, 5.2） years. Three patients began omalizumab treatment before conception, with a dose of 300 mg every 3 - 4 weeks; after 3 - 8 sessions of treatment, pregnancy was confirmed, followed finally by successful deliveries. Five patients started omalizumab treatment at doses of 150 - 300 mg/4 weeks during lactation. All the 8 patients received omalizumab injections for 3 - 24 sessions, with an average of 10.38 sessions. Before omalizumab treatment, the UAS7 scores were 6.0 （2.8，23.5） points; during the treatment, UAS7 scores decreased to 0 - 6 points, and CSU symptoms were completely controlled or well controlled. None of the 3 pregnant patients reported maternal adverse events, small-for-gestational-age or low-birth-weight infant outcomes, premature delivery （< 37 weeks）, spontaneous abortion （< 28 weeks）, congenital malformations in infants, or infant adverse events. One lactating patient developed a mild fever and fatigue 6 hours after the first omalizumab injection, which resolved spontaneously within 48 hours; the other 4 lactating patients did not experience any maternal or infant adverse events. Conclusion Omalizumab may be an effective and safe treatment option for CSU patients during pregnancy and lactation.

Key words: Urticaria, Chronic spontaneous urticaria, Omalizumab, Pregnancy, Lactation, Efficacy, Safety