Differences in ovarian hormones in relation to parity and time since last birth

Fertil Steril. 2014 Jun;101(6):1773-80.e1. doi: 10.1016/j.fertnstert.2014.02.047. Epub 2014 Mar 28.


Objective: To examine ovarian function in relation to parity and time since last birth.

Design: Cross-sectional study.

Setting: Health-care program in California.

Patient(s): 346 naturally cycling women, aged 18 to 39 years.

Intervention(s): None.

Main outcome measure(s): Mean follicular urinary estradiol metabolite concentration (E1C) (cycle days -8 to -1), mean luteal progesterone metabolite concentration (PdG) (days 0 to +10), and cycle phase lengths in ovulatory cycles.

Result(s): After the women had collected daily urine samples for up to eight menstrual cycles, we measured the E1C and PdG using enzyme-linked immunoassay. The cycle phase lengths were calculated from the hormone profiles and daily diaries. Women who had given birth within the previous 3 years had lower E1C than the nulliparous women and women who last given birth >3 years earlier. Among the parous women, E1C was positively associated with the time since last birth. Women who last gave birth >3 years earlier had longer follicular phases than the nulliparous women. There were no associations between parity and PdG or luteal phase length.

Conclusion(s): Our cross-sectional data suggest that ovarian function differs in nulliparous and parous women and is positively associated with the time since last birth. Longitudinal research is needed to explore within-woman changes in ovarian function prepartum and postpartum.

Keywords: Estradiol; fecundity; menstrual cycle; motherhood; ovarian function.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adolescent
  • Adult
  • Biomarkers / urine
  • California
  • Cross-Sectional Studies
  • Estradiol / urine*
  • Female
  • Humans
  • Menstrual Cycle / urine*
  • Ovary / metabolism*
  • Parity*
  • Pregnancy
  • Progesterone / urine*
  • Time Factors
  • Young Adult


  • Biomarkers
  • Progesterone
  • Estradiol