Using Quantitative Hormone Monitoring to Identify the Postpartum Return of Fertility

Abstract

Background and Objectives: The Marquette Method (MM) has been used for many years to track the postpartum return of fertility using the ClearBlue Fertility Monitor (CBFM). A new quantitative urine hormone monitor (the Mira Analyzer) was compared to the CBFM in one previous study, and using this pilot data, several women have started to use the Mira Analyzer in the postpartum transition to fertility. Materials and Methods: This study was a retrospective, observational case series that analyzed hormone data on the Mira Analyzer during the postpartum period. Participants were invited to share their postpartum cycle and hormone observations. Quantitative hormones in the urine included estrone-3-glucuronide (E3G), luteinizing hormone (LH), and pregnanediol glucuronide (PDG). Data were collected using an electronic survey and an online portal for hormone data. Data collected included participant demographics, menstrual cycle characteristics, and reproductive health history. Hormone range values were calculated, and thresholds were identified that would best predict the first ovulation that led to the first postpartum menstrual period, as well as in transition cycles. Hormone patterns were identified in the context of previous studies. Results: Twenty participants contributed data for the analysis. Triggering ovulation before the first period postpartum (Cycle 0) usually required higher LH thresholds than for regularly cycling women. Three different patterns were observed in the return of fertility postpartum: minimal ovarian activity, follicular activity without ovulation, and the early return of fertility. Abstinence rates for avoiding pregnancy with experimental thresholds were calculated. Conclusions: Higher LH thresholds in Cycle 0 suggest a decreased responsiveness of the ovaries to LH stimulation from the pituitary. This study replicates postpartum hormone patterns from a previous study. Larger studies are planned to evaluate the effectiveness for avoiding pregnancy using the Mira Analyzer in the postpartum return of fertility.

Keywords: breastfeeding; estrone-3-glucuronide; luteinizing hormone; ovulation; postpartum; pregnanediol glucuronide; urine hormone tests.

Figure 1

The Mira Analyzer measures follicle-stimulating hormone (FSH), estrone-3-glucuronide (E₁3G), luteinizing hormone (LH), and pregnanediol glucuronide (PDG) in the urine. It is comparable in identifying hormone changes to the well-known ClearBlue Fertility Monitor. This figure is a partial reproduction of Figure 1 from ref. [3].

Figure 2

(A) Reproduction of Figure 2 from Bouchard et al. 2018 [1] showing ovarian quiescence with delayed ovulation (mucus/bleeding colours—green: dry; yellow: non-lubricative sticky mucus; blue: lubricative, clear, stretchy mucus; red: bleeding/menstruation; TE: total urinary estrogens; end of full breastfeeding with introduction of solids indicated by arrow at 4.5 months, and complete weaning indicated by arrow at 11 months). Mira Analyzer data in (B,C) show very low estrogenic activity with LH rises (marked levels) that did not lead to ovulation. In (C), a high LH surge of 66 was required to trigger ovulation, confirmed with a PDG rise (marked) and the first menses, leading to the first menstrual cycle in (D).

Figure 3

(A) Reproduction of Figure 3 [1] showing follicular activity with delayed ovulation (mucus/bleeding colours—green: dry; yellow: non-lubricative sticky mucus; blue: lubricative, clear, stretchy mucus; red: bleeding/menstruation; TE: total urinary estrogens; end of full breastfeeding with introduction of solids indicated by arrow at 3.0 months, and complete weaning indicated by arrow at 4.1 months). (B–D) Cycle 0 data from the Mira Analyzer show multiple waves of high estrogenic activity throughout, and some LH levels that are relatively high but did not lead to ovulation. Progesterone rises are erratic and not correlated with ovulation with no menses yet.

Figure 4

(A) Reproduction of Figure 4 [1] showing early return of fertility postpartum (mucus/bleeding colours—green: dry; yellow: non-lubricative sticky mucus; blue: lubricative, clear, stretchy mucus; red: bleeding/menstruation; TE: total urinary estrogens; end of full breastfeeding with introduction of solids indicated by arrow at 5.0 months, and complete weaning indicated by arrow at 5.7 months). (B) The first cycle postpartum with Mira, showing high estrogen in the fertile window leading up to a high LH surge and a weak progesterone response with a short (6-day) luteal phase. Cycle 2 (C) shows an appropriate estrogen rise in the fertile window, an LH surge, and a 6-day luteal phase. Cycle 3 (D) shows an improved follicular estrogen rise, a normal LH surge, and a higher PDG response with an 11-day luteal phase (i.e., gradual return to normal fertility). The longer luteal phase in the third cycle suggests improved chances of fertility.