An official website of the United States government
The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before
sharing sensitive information, make sure you’re on a federal
government site.
The site is secure.
The https:// ensures that you are connecting to the
official website and that any information you provide is encrypted
and transmitted securely.
Guzman ER, Shen-Schwarz S, Benito C, Vintzileos AM, Lake M, Lai YL.Guzman ER, et al.Am J Obstet Gynecol. 1999 Oct;181(4):793-7. doi: 10.1016/s0002-9378(99)70303-0.Am J Obstet Gynecol. 1999.PMID: 10521731