Study of Ceftriaxone and Benzathine Penicillin G During Pregnancy

Inclusion Criteria: * Is of legal age or circumstance to provide independent informed consent as determined by site standard operating procedures (SOPs) and consistent with Institutional Review Board (IRB) policies and procedures and is willing and able to provide written informed consent for her own and, if applicable (Arm 2), her infant's study participation * At screening, has a viable singleton intrauterine pregnancy of any gestational age confirmed by fetal ultrasound, as determined by the site investigator based on medical records, with trimester documented based on the best available obstetric estimate * At screening, is receiving or expected to receive one of the following drugs under study as prescribed by a clinical care provider and documented in medical records: * Ceftriaxone: IV or IM administration for an indication other than syphilis * Benzathine penicillin G: IM administration for treatment of syphilis * At entry, expects to remain in the geographic area of the study site during pregnancy and at least 30 days postpartum Exclusion Criteria: * Previously enrolled in this study * Requires desensitization to ceftriaxone or benzathine penicillin G as determined by the site investigator based on pregnant participant report and available medical records * Has any of the following as determined by the site investigator based on pregnant participant report and available medical records: * Current indication for hemodialysis * Current indication for intensive care unit hospitalization * Creatinine (Cr) ≥ 3.5 x upper limit of normal (ULN) at any time during the current pregnancy and/or chronic kidney disease Stage 5 * Receipt of any of the following prohibited medications within seven days prior to entry as determined by the site investigator based on pregnant participant report and available medical records: * Probenecid * Penicillin * Arm 1A: any penicillin * Arm 1B: any penicillin * Arm 2: penicillin other than benzathine penicillin G * Benzapril * Chlorpropamide * Diflunisal * Irbesartan * Ketoprofen * Ketorolac tromethamine * Meclofenamic acid * Mefenamic acid * Oxaprozin * Parecoxib * Penciclovir * Pioglitazone * Telmisartan * Valsartan * Receipt of any investigational agent within seven days prior to entry as determined by the site investigator based on pregnant participant report and available medical records * Has any documented or suspected clinically significant condition that, in the opinion of the site investigator, would make participation in the study unsafe, complicate interpretation of study outcome data, or otherwise interfere with achieving study objectives