0036-3634 0036-3634 S0036-36342017000200122 10.21149/8230 México 00 04 2017 00 04 2017 59 2 122 123 ACOG Committee on Practice Bulletins-Obstetrics 2007 109 1007-19 2008 76 468-75 1992 71 425-38 1984 17 194-201 2011 284 593-7