Comment in

• The enigma of spontaneous preterm birth.

  Braillon A, Bewley S. Braillon A, et al. N Engl J Med. 2010 May 27;362(21):2032; author reply 2033-4. doi: 10.1056/NEJMc1002978. N Engl J Med. 2010. PMID: 20505185 No abstract available.
• The enigma of spontaneous preterm birth.

  Fry-Johnson YW, Rowley DL. Fry-Johnson YW, et al. N Engl J Med. 2010 May 27;362(21):2032; author reply 2033-4. N Engl J Med. 2010. PMID: 20518104 No abstract available.
• The enigma of spontaneous preterm birth.

  Antony AC. Antony AC. N Engl J Med. 2010 May 27;362(21):2033; author reply 2033-4. N Engl J Med. 2010. PMID: 20518105 No abstract available.
• The enigma of spontaneous preterm birth.

  Takayama JI, Matsuo N. Takayama JI, et al. N Engl J Med. 2010 May 27;362(21):2032-3; author reply 2033-4. N Engl J Med. 2010. PMID: 20518106 No abstract available.