Vanderbilt Clinical Trials

For the mother: - Female 18-40 years of age who is in good general health, is fully able to provide consent to participate in the study, anticipates being available for the duration of the study, and is willing to comply with all study procedures - Singleton pregnancy - Completed ≧3 prenatal care visits at Vanderbilt University Medical Center (VUMC) (any facility) - Scheduled for a planned C-section due to a repeat C-section at VUMC (main campus only) - Planning to have general pediatric care for the infant at VUMC (main campus or One Hundred Oaks campus) - Intention to breastfeed partially or exclusively - No intent to relocate outside the middle Tennessee region within 18-24 months of recruitment For the infant: - Estimated gestational age ≧37 weeks - Birth weight ≧2,500 grams

For the mother: - Previous child with Group B Streptococcus (GBS) infection at any age - Hepatitis B, hepatis C, or human immunodeficiency virus infection at any age - Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in the 4 weeks prior to delivery or a household contact with a confirmed SARS-CoV-2 infection in the 4 weeks prior to delivery - Fever (≧100.4°F [38°C]) in the 72 hours prior to delivery - Symptoms (e.g., dysuria, pruritus, or discharge) suggestive of a genitourinary infection (e.g., bacterial vaginosis, vaginal yeast infection, chorioamnionitis, or urinary tract infection) on the day of delivery - Physical exam findings (e.g., fever [≧100.4°F (38°C)] or vesicles, warts, or ulcers in the genital, perineal, or anal region) suggestive of a genitourinary infection on the day of delivery (performed as part of the screening procedures for this study if not performed as standard of care) - Laboratory evidence of any of the following: - GBS bacteriuria in urine samples collected at any time during current pregnancy (performed as standard of care) - GBS colonization in rectovaginal swabs collected at ≧35 weeks of current pregnancy (performed as standard of care) - Chlamydia, trichomoniasis, or gonorrhea in urine samples collected in the first trimester current pregnancy (performed as standard of care) - Chlamydia, trichomoniasis, or gonorrhea in urine samples collected at ≧35 weeks of current pregnancy (performed as part of the screening procedures for this study) - Hepatitis B, hepatis C, human immunodeficiency virus, or syphilis infection in blood samples collected in the first trimester current pregnancy (performed as standard of care) - Hepatitis B, hepatis C, human immunodeficiency virus, or syphilis in blood samples collected at ≧35 weeks of current pregnancy (performed as part of the screening procedures for this study) - SARS-CoV-2 infection in nasal swabs collected in the 72 hours prior to delivery (performed as standard of care) - Maternal vaginal pH>4.5 on the day of delivery (performed as part of the screening procedures for this study) - For women 21-29 years of age: Abnormal Pap smear in the 3 years prior to delivery (performed as standard of care) - For women 21-40 years of age: Abnormal Pap smear with cervical human papilloma virus co-testing in the 5 years prior to delivery, abnormal Pap Smear alone in the 3 years prior to delivery, or abnormal cervical human papilloma virus testing alone in the 5 years prior to delivery (performed as standard of care) - Pelvic inflammatory disease at any age - Diabetes (including type I, type II, and gestational diabetes) at any age - Any serious obstetric disease (e.g., preeclampsia, placenta previa, placental abruption, severe bleeding, or thromboembolic disease) - C-section scheduled for a genitourinary infection that would have interfered with vaginal delivery (e.g., genital herpetic lesions) - Lack of available prenatal screening tests - Expected preterm delivery - Need for a switch from a planned C-section to an emergency C-section - Onset of labor or rupture of membranes prior to delivery - Use of systemic (oral, intramuscular, or intravenous) antibiotics in the 4 weeks prior to delivery (except for those being administered as part of the C-section) - Use of systemic (oral, intramuscular, or intravenous) immunosuppressive, biologic, or chemotherapeutic agents in the 3 months prior to delivery (except for systemic immunosuppressive agents not being used for their immunosuppressive effects [e.g., prenatal intramuscular beclomethasone for fetal lung maturation]) - Pregnancy as the result of an assisted reproductive technology or surrogacy - Participation in another clinical trial that involves an intervention that could impact the quality or interpretation of the study data as deemed by the PI or co-investigators - Other past or current medical problems that could compromise the safety of participants, interfere with their ability to comply with study requirements, or impact the quality or interpretation of the study data as deemed by the PI or co-investigator For the infant: - Need for neonatal measures outside routine clinical care (i.e., drying, tactile stimulation, bulb syringe or catheter suction of nose and mouth, or temperature maintenance) or transfer to the neonatal intensive care unit immediately after delivery - Thick particulate meconium noted during delivery - Physical exam findings (e.g., tachypnea, nasal flaring, retractions, cyanosis, or grunting) suggestive of neonatal acute respiratory distress immediately after delivery (performed as part of the screening procedures for this study) - Prenatal or immediate postnatal diagnosis of a serious genetic, respiratory, cardiovascular, or neurological disease - Prenatal or immediate postnatal diagnosis of intrauterine growth restriction - Prenatal or immediate postnatal diagnosis of a major congenital anomaly (e.g., cleft lip or palate, cystic hygroma, or giant omphalocele) - Participation in another clinical trial that involves an intervention that could impact the quality or interpretation of the study data as deemed by the PI or co-investigators - Other past or current medical problems that could compromise the safety of participants, interfere with their ability to comply with study requirements, or impact the quality or interpretation of the study data as deemed by the PI or co-investigators