Light Microscopy and Proteomic Patterns of Ovulation in Cervical Mucus

Yolanda Fernandez-Hermida; Federica Vincenzoni; Domenico Milardi; Anna Laura Astorri; Andrea Urbani; Giuseppe Grande; Rafael Azagra

doi:10.3390/life12111815

Menstrual Cycle · Cycle Biomarkers

Light Microscopy and Proteomic Patterns of Ovulation in Cervical Mucus

Fernandez-Hermida Y, Vincenzoni F, Milardi D, Astorri AL, Urbani A, Grande G, Azagra R

Published November 7, 2022 Life (Basel, Switzerland)

DOI 10.3390/life12111815 PMID 36362970 PMC PMC9698449

RRM Academy Synopsis

Cervical mucus protein levels differed by cycle phase in six women

Cervical mucus protein levels differed by cycle phase in six healthy women. In this small lab study, 17 mucus samples were checked under a microscope and by mass spectrometry. Of 48 proteins found, 25 were proposed as possible ovulation markers.

Key Findings

Six fertile women aged 25 to 30 with regular cycles gave cervical mucus samples on days 7, 12 and 18 of one cycle. Seventeen samples were analyzed.
Light microscopy identified four mucus types, L, S, P and G, by their crystal patterns. The patterns matched earlier descriptions in the literature.
Mass spectrometry identified 48 proteins in total across the three cycle-day groups.
Seventeen proteins significantly decreased and eight significantly increased on day 18 compared with days 7 and 12. The authors propose these 25 as potential ovulation biomarkers.
Seven proteins were absent on day 18, when most samples were in the ovulatory phase. All seven take part in the immune response.

Interpretation

The study is a small exploratory laboratory analysis. Six women each gave samples once on three days of a single cycle, and the proteins were measured in pooled samples grouped by cycle day. The paper lists which proteins change and proposes candidates. The study did not test whether any protein predicts ovulation in advance. The authors acknowledge the relatively small sample. Samples were assigned to a cycle phase by their microscope pattern and the date of the last period. The authors suggest ovulation came later in the cycle than clinical guidelines assume, on the strength of these six women.

RRM Context

Cervical mucus is a working sign in fertility awareness-based methods. The authors say physicians and women using them treat mucus as an indirect guide to when ovulation happens. This paper adds a laboratory view of what changes inside the mucus. The authors cite a study of 612,613 cycles in which only 13% of cycles were 28 days long. They call the fertile window highly unpredictable even when cycles are regular.

Our editorial summary of this paper, not the article's abstract.

Abstract

There is an increasing number of couples interested in identifying the fertile window for the purpose of conceiving. From what has been published so far, it can be concluded that there are no reliable methods to predict ovulation, and, therefore, to predict the fertile window. Proteins of the cervical mucus (CM) could behave as biomarkers to allow the early and precise identification of ovulation. CM samples were collected from the lumen of the cervical canal from women of reproductive age, on three different days of the same menstrual cycle. Samples were first analyzed and classified by light microscopy. High-resolution mass spectrometry and bioinformatic analysis were performed afterwards to determine the in vivo changes of CM protein composition. CM underwent cyclical changes in its biophysical composition, which were evidenced by changes in the crystallographic patterns observed under the light microscope. The proteomic analysis revealed changes in the protein composition of CM along the cycle. Twenty-five out of the forty-eight total proteins identified could become potential biomarkers of ovulation. The coordinated changes in the composition of the CM around the time of ovulation could be happening to specifically grant access to a foreign body, such as the sperm might be.

Topics

Menstrual Cycle › Cycle Biomarkers › Cervical Mucus · Fertility Awareness › Biomarkers › Cervical Mucus · Diagnostics › Cycle Biomarkers › Cervical Mucus Monitoring

Yolanda Fernandez-Hermida, Federica Vincenzoni, Domenico Milardi, Anna Laura Astorri, Andrea Urbani, Giuseppe Grande, Rafael Azagra

Y Fernandez-Hermida, F Vincenzoni, D Milardi, A Astorri, A Urbani, G Grande, R Azagra

PMID 36362970 36362970 DOI 10.3390/life12111815 10.3390/life12111815 Fernandez-Hermida et al. 2022, Fernandez-Hermida 2022

Light Microscopy and Proteomic Patterns of Ovulation in Cervical Mucus

Cervical mucus protein levels differed by cycle phase in six women

Key Findings

Interpretation

RRM Context

Abstract

Topics

By this author

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