Anti-Bacterial Agents; DNA Methylation; Fetal Development/genetics; Infant, Low Birth Weight; Prenatal Exposure Delayed Effects; Adult; Anti-Bacterial Agents/adverse effects; Birth Weight; Calcium-Binding Proteins; Cardiovascular Diseases/genetics; Cell Cycle Proteins/genetics; DNA Methylation/genetics; Epigenesis, Genetic; Female; Genomic Imprinting; Humans; Infant, Newborn; Insulin-Like Growth Factor II/genetics; Intercellular Signaling Peptides and Proteins/genetics; Kruppel-Like Transcription Factors/genetics; Membrane Proteins/genetics; Neoplasms/genetics; Nerve Tissue Proteins/genetics; Obesity/genetics; Pregnancy; Prenatal Exposure Delayed Effects/epidemiology; Prenatal Exposure Delayed Effects/genetics; Prospective Studies; Proteins/genetics; RNA, Long Noncoding/genetics; Sarcoglycans/genetics; Sequence Analysis, DNA; Transcription Factors/genetics; Tumor Suppressor Proteins/genetics; United States/epidemiology