title: Late infertile days in early postpartum cycles.
abstract: Luteal phase abnormalities in early menstrual cycles after pregnancy have been shown to cause confusion in the practice of natural family planning (NFP) for some patients and to restrict severely the number of late infertile days available to others. The cause of the abnormalities is uncertain but appears to be related to the nursing status of the patient.
mesh_terms: D001831:Body Temperature; D002582:Cervix Mucus / Q000032:analysis; D002940:Circadian Rhythm; D004967:Estrogens / Q000652:urine; D005193:Family Planning Services; D005260:Female; D005298:Fertility; D006801:Humans; D008183:Luteal Phase; D049590:Postpartum Period; D011247:Pregnancy; D011276:Pregnanediol / Q000652:urine; D013997:Time Factors
chemical_list: D004967:Estrogens; D011276:Pregnanediol