title: Monitoring of ovarian activity by measurement of urinary excretion rates using the Ovarian Monitor, Part IV: the relationship of the pregnanediol glucuronide threshold to basal body temperature and cervical mucus as markers for the beginning of the post-ovulatory infertile period.
abstract: OBJECTIVE
  Do the basal body temperature (BBT) shift and the cervical mucus markers for the beginning of the post-ovulatory infertile phase (POIP) of a menstrual cycle agree with the corresponding urinary pregnanediol glucuronide (PdG) threshold value?
  
  
  CONCLUSIONS
  Perfect agreement between the cervical mucus markers and BBT shift and the hormonal definition of the start of post-ovulatory infertility occurred for only 7-17% of the cycles.
  
  
  BACKGROUND
  The PdG threshold of 7.0 µmol/24 h is an objective and accurate marker for the beginning of the POIP. The rise in serum progesterone also produces the BBT shift and changes in cervical mucus which determine the mucus peak. Serum progesterone and urinary PdG are closely correlated when variations in urine volume are taken into account.
  
  
  METHODS
  Individual menstrual cycle profiles of urinary PdG excretion rates for 91 fertile cycles from normally cycling women were analysed to identify the day of the beginning of the POIP. These days were compared with those determined by the day of the BBT shift +2 days, the day of the mucus peak +4 days and the later of these two indicators. The study lasted 3 years.
  
  
  METHODS
  A total of 62 women with normal menstrual cycles were recruited from three centres: Palmerston North, New Zealand; Sydney, Australia and Santiago, Chile. The cycles were displayed individually in a proprietary database program which recorded the PdG excretion rates, the BBT shift day and the cervical mucus peak day. A group of 15 women from a separate Chilean study had PdG urinary data measured as well as their day of ovulation determined by ultrasound.
  
  
  RESULTS
  The BBT and cervical mucus markers differed significantly in their identification of the beginning of the POIP when compared with the PdG excretion rate of 7.0 µmol/24 h. The observation that the BBT shift day and the mucus peak day could be identified even though the PdG excretion rates were still at baseline levels in some cycles could lead to an unexpected pregnancy for women using these natural family planning (NFP) indicators.
  
  
  CONCLUSIONS
  The study consisted only of fertile cycles from women with regular cycles of 20-40 days duration. All the women were intending to avoid a pregnancy during the study, thus the limits of the fertile window were not tested.
  
  
  CONCLUSIONS
  The NFP signals occurring earlier than the PdG threshold day could lead to an unexpected pregnancy. The signals occurring on the same day or later than the PdG threshold would not lead to unexpected pregnancies, but would require extra abstinence that could lead to non-compliance with the NFP method. A possible improvement in reliability of NFP methods is suggested.
  
  
  BACKGROUND
  This study (project #90905) was funded by the NDP/UNFPA/UNICEF/WHO/World Bank Special Programme of Research, Development and Research Training in Human Reproduction (HRP). D.G.C. currently works for a diagnostic development company, Science Haven Ltd. The other authors have nothing to declare.
authors.affiliation: Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand l.f.blackwell@massey.ac.nz.
authors.forename: Leonard F
authors.initials: LF
authors.lastname: Blackwell
authors.affiliation: Pontificia Universidad Católica de Chile, Santiago, Chile Fundación Médica San Cristóbal, Santiago, Chile.
authors.forename: Pilar
authors.initials: P
authors.lastname: Vigil
authors.affiliation: Programa de Cuidado y Estudio de la Fertilidad: Procef, Universidad de los Andes, Santiago, Chile.
authors.forename: María Elena
authors.initials: ME
authors.lastname: Alliende
authors.affiliation: Deviot Institute, Deviot, Tasmania 7275, Australia.
authors.forename: Simon
authors.initials: S
authors.lastname: Brown
authors.affiliation: Department of Reproductive Health and Research and UNDP/UNFPA/UNICEF/WHO/World Bank Special Programme of Research, Development and Research Training in Human Reproduction (HRP), World Health Organization, Geneva, Switzerland.
authors.forename: Mario
authors.initials: M
authors.lastname: Festin
authors.affiliation: Science Haven Limited, c/o Massey University, Palmerston North, New Zealand.
authors.forename: Delwyn G
authors.initials: DG
authors.lastname: Cooke
mesh_terms: D000328:Adult; D015415:Biomarkers; D001831:Body Temperature; D002582:Cervix Mucus; D005260:Female; D020719:Glucuronides / Q000652:urine*; D006801:Humans; D008597:Menstrual Cycle / Q000378:metabolism / Q000652:urine; D010061:Ovulation Detection; D011276:Pregnanediol / Q000031:analogs & derivatives / Q000652:urine*; D011374:Progesterone / Q000097:blood
chemical_list: D015415:Biomarkers; D020719:Glucuronides; D011374:Progesterone; D011276:Pregnanediol
keywords: basal body temperature; home urine test; menstrual cycle profiles; oestrone glucuronide; pregnanediol glucuronide