CD4-Positive T-Lymphocytes/immunology; Fetal Blood/immunology; Fetal Diseases/immunology; Fetus/immunology; Infant, Newborn/immunology; Infectious Disease Transmission, Vertical; Malaria, Falciparum/immunology; Parasitemia/immunology; Placenta Diseases/immunology; Pregnancy Complications, Infectious/immunology; T-Lymphocyte Subsets/immunology; Adult; Animals; CD4-Positive T-Lymphocytes/chemistry; CD4-Positive T-Lymphocytes/metabolism; Female; Fetal Blood/parasitology; Fetal Diseases/parasitology; Forkhead Transcription Factors/analysis; Humans; Infant, Newborn/blood; Interferon-gamma/metabolism; Interleukin-10/metabolism; Malaria, Falciparum/congenital; Malaria, Falciparum/embryology; Male; Parasitemia/congenital; Parasitemia/embryology; Placenta Diseases/parasitology; Pregnancy; Pregnancy Complications, Infectious/parasitology; T-Lymphocyte Subsets/chemistry; T-Lymphocyte Subsets/metabolism; Transforming Growth Factor beta/metabolism; Tumor Necrosis Factor-alpha/metabolism