Inclusion Criteria:

• Subject (or a legally authorized representative) consent obtained prior to enrollment. Consent will be obtained in compliance with any country-specific regulations or requirements
• Confirmation of ongoing pregnancy. Subjects with unknown outcomes will be classified as prospective pregnancies; subjects who have undergone prenatal testing (eg, targeted ultrasound, amniocentesis) regardless of findings will be classified as retrospective pregnancies
• Diagnosed with PKU per local standard of care
• Documentation that the subject was treated with pegvaliase at any point starting from 2 weeks prior to the date of LMP
• Agrees to permit the Investigator (ie, CRP, CCA, PI) to contact the subject's HCPs (eg, PCP, PKU-treating physician, OB, nurse, midwife) and the infant's HCP (eg, pediatrician, neonatologist) for medical information

Exclusion Criteria:

• Currently participating in a BioMarin sponsored interventional study of any investigational product, device, or procedure