title: Natalizumab use during the third trimester of pregnancy.
abstract: OBJECTIVE
  Natalizumab reduces multiple sclerosis relapses very effectively; however, severe disease activity may return once natalizumab treatment is withdrawn, as recommended during pregnancy. Sometimes restarting natalizumab treatment may be the best option for the mother, but the consequences for the infant are unknown. Except for a few single case reports, to our knowledge, comprehensive data about third-trimester natalizumab exposure are scant.
  
  
  METHODS
  In a case series of 12 women with 13 pregnancies and highly active multiple sclerosis who were treated with natalizumab during their third trimester of pregnancy, we assessed the clinical and laboratory effects on the newborns. We observed mild to moderate hematologic alterations in 10 of 13 infants including thrombocytopenia and anemia. In a subsample of 5 mother-child pairs, we analyzed natalizumab levels in the umbilical cord blood. Natalizumab was detectable in all 5 newborns.
  
  
  CONCLUSIONS
  Natalizumab can be a therapeutic option in patients with highly active multiple sclerosis during pregnancy. We recommend that a pediatrician be available at the time of delivery to evaluate for potential complications of anemia and thrombocytopenia in newborns exposed to natalizumab during the third trimester.
authors.affiliation: Department of Neurology, St Josef-Hospital, Ruhr University Bochum, Bochum, Germany.
authors.forename: Aiden
authors.initials: A
authors.lastname: Haghikia
authors.affiliation: Department of Research and Evaluation, Kaiser Permanente Southern California, Pasadena.
authors.forename: Annette
authors.initials: A
authors.lastname: Langer-Gould
authors.affiliation: Department of General Pediatrics, University Children's Hospital Münster, Münster, Germany.
authors.forename: Georg
authors.initials: G
authors.lastname: Rellensmann
authors.affiliation: University Children's Hospital Mannheim, Heidelberg University, Heidelberg, Germany.
authors.forename: Henriette
authors.initials: H
authors.lastname: Schneider
authors.affiliation: University Children's Hospital Mannheim, Heidelberg University, Heidelberg, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Tenenbaum
authors.affiliation: Neurologic Practice Hamburg, Hamburg, Germany.
authors.forename: Birte
authors.initials: B
authors.lastname: Elias-Hamp
authors.affiliation: Neurologic Practice Barsinghausen, Barsinghausen, Germany.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Menck
authors.affiliation: Department of Neurology, University of Bonn, Bonn, Germany.
authors.forename: Julian
authors.initials: J
authors.lastname: Zimmermann
authors.affiliation: Faculty of Pharmacy, University of Dusseldorf, Dusseldorf, Germany.
authors.forename: Sandra
authors.initials: S
authors.lastname: Herbstritt
authors.affiliation: Department of Neurology, kbo-Isar-Amper-Klinikum München-Ost, Munich, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Marziniak
authors.affiliation: Institute for Clinical Neuroimmunology, Ludwig-Maximilians-University, Munich, Germany.
authors.forename: Tania
authors.initials: T
authors.lastname: Kümpfel
authors.affiliation: Institute for Clinical Neuroimmunology, Ludwig-Maximilians-University, Munich, Germany.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Meinl
authors.affiliation: Biogen Idec, Cambridge, Massachusetts.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Plavina
authors.affiliation: Department of Neurology, St Josef-Hospital, Ruhr University Bochum, Bochum, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Gold
authors.affiliation: Department of Neurology, St Josef-Hospital, Ruhr University Bochum, Bochum, Germany2Department of Research and Evaluation, Kaiser Permanente Southern California, Pasadena.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Hellwig
mesh_terms: D000328:Adult; D000751:Anemia, Neonatal / Q000139:chemically induced; D000818:Animals; D061067:Antibodies, Monoclonal, Humanized / Q000009:adverse effects* / Q000097:blood; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000139:chemically induced*; D007964:Leukocytosis / Q000139:chemically induced; D009103:Multiple Sclerosis / Q000188:drug therapy*; D000069442:Natalizumab; D011247:Pregnancy; D011250:Pregnancy Complications, Hematologic / Q000188:drug therapy*; D011263:Pregnancy Trimester, Third; D013921:Thrombocytopenia / Q000139:chemically induced
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D000069442:Natalizumab