A Worldwide Pregnancy Safety Study to Assess Maternal, Fetal, and Infant Outcomes Following Exposure to Efgartigimod During Pregnancy and/or Breastfeeding.

Inclusion Criteria: * Women with exposure to efgartigimod or efgartigimod PH20 SC any time within 25 days prior to conception or any time during pregnancy, or women with exposure to efgartigimod or efgartigimod PH20 SC during breastfeeding. The timeframe of 25 days prior to conception is calculated based on five times the efgartigimod half-life, which is 3 to 5 days. * Written/verbal informed consent or eConsent (depending on country regulations) (for adolescents under the age of majority, written/verbal informed assent or eConsent by the pregnant minor (where applicable) and written/verbal informed consent or eConsent by the parent/legal guardian). Exclusion Criteria: * None