EARLY-PREG: A Preconception Cohort Study Based on Counterfactuals to Study Maternal-Embryonic Molecular Interactions

NCT07358026 | Recruiting

• 4 other identifiers: 17-03-06MEL109112011, MEL109112011R4MEL109112011R5, MEL131032017R1MEL205062018, REH042024-01
• Study Type: observational
• Target: 223
• Locations: 1 country
• Sites: 1

Brief Summary

EARLY-PREG is an open-cohort clinical study with a preconception, longitudinal, bidirectional and counterfactual design. The aim of this cohort is to investigate the proteomic signatures of maternal-embryonic communication by interrogating a growing biorepository of maternal fluids and tissues collected during the first two weeks after fertilisation. Participants in the EARLY-PREG cohort consist of healthy couples seeking pregnancy, as well as women who are not seeking to conceive. The three main outcomes in the cohort are defined according to menstrual cycles in which conception is achieved and those in which conception is not achieved. Their clinical definitions are as follows:

• Pregnancy with a full-term live birth refers to the cycle in which the ovum is fertilised, leading to pregnancy, with beta-hCG levels above the clinical threshold for a positive pregnancy test.
• Early pregnancy loss refers to a miscarriage up to 12 6/7 weeks.
• Non-pregnancy refers to a menstrual cycle in which conception does not occur, confirmed by a clinically negative beta-hCG test. When referring to the same individual, this is, by definition, considered the counterfactual to the corresponding conception cycle.

Conditions

Early Pregnancy; Childbirth; Pregnancy; Early Pregnancy Loss; Healthy

Keywords

longitudinal study; counterfactual design; embryo-mother crosstalk; biorepository; maternal fluids; menstrual cycle; preconception open cohort

Outcome Measures

Primary Outcomes (3)

• Number of menstrual cycles leading to full-term pregnancies

  This outcome refers to the menstrual cycle in which the ovum is fertilised, leading to pregnancy with a full term live birth. The conception cycle requires beta-hCG levels above the clinical threshold for a positive pregnancy test, which is determined in peripheral venous blood on the 14th day post-ovulation.

  From enrollment for up to six menstrual cycles (each cycle ranges from 21-35 days) or until pregnancy resulting in live birth, whichever occurs first.

• Number of menstrual cycles not leading to pregnancy

  This outcome refers to a menstrual cycle in which pregnancy does not occur. When referring to the same individual, it is, by definition, considered the counterfactual to the conception cycle described above. A non-conception cycle is confirmed by a clinically negative beta-hCG test, which is determined in peripheral venous blood on the 14th day post-ovulation. This cycle is characterised by the absence of a clinical pregnancy.

  From enrollment for up to six menstrual cycles (each cycle ranges from 21-35 days) or until pregnancy occurs, whichever occurs first.

• Number of menstrual cycles leading to early pregnancy loss

  This outcome refers to the menstrual cycle in which the ovum is fertilised, leading to a miscarriage until 12 6/7 weeks. The conception cycle requires beta-hCG levels above the clinical threshold for a positive pregnancy test, which is determined in peripheral venous blood on the 14th day post-ovulation.

  From the time beta-hCG levels rise above the clinical threshold for a positive pregnancy test until a miscarriage occurring up to 12 6/7 weeks.

Study Arms (2)

CONCEPTION CYCLE

Conception cycle refers to the menstrual cycle in which the ovum is fertilised, leading to pregnancy. Confirmation of a conception cycle requires beta-hCG levels above the clinical threshold for a positive pregnancy test, which is determined in peripheral venous blood on the 14th day post-ovulation.

Other: EMBRYO EXPOSURE

NON-CONCEPTION CYCLE

Non-conception cycle refers to a menstrual cycle in which pregnancy does not occur. When referring to the same individual, it is, by definition, considered the counterfactual to the conception cycle described above. Confirmation of a non-conception cycle requires a clinically negative beta-hCG test, determined in peripheral venous blood on the 14th day post-ovulation. This cycle is characterised by the absence of a clinical pregnancy.

Interventions

EMBRYO EXPOSURE OTHER

The counterfactual design of EARLY-PREG enables the comparison of the systemic and localised physiological effects associated with embryo appearance and implantation in an individual (the factual) against the physiological state of the same individual without experiencing pregnancy (the counterfactual).

CONCEPTION CYCLE

Eligibility Criteria

• Age: 18 Years - 40 Years
• Sex: female
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)
• Sampling Method: Non-Probability Sample

Study Population

Women visiting gynaecologists, and midwives in private practices, public hospitals, and Family Health Centres (CESFAMs) in the Biobio region of Chile.

You may qualify if:

• being between 18 and 40 years of age
• not being pregnant
• normal colposcopy
• body mass index (BMI) between 18 and 29
• regular menstrual cycles (21-35 days)
• absence of chronic diseases (hypertension, diabetes mellitus, cancer, depression, personality disorder, thyroid pathology, polycystic ovary syndrome, or hyperprolactinemia).
• If seeking pregnancy, they were included if their partners were males between 18 and 40 years old, without pathologies (diabetes mellitus, depression, personality disorder, or cancer), were not taking chronic medication, without erectile disorders, BMI between 18 and 29.9, moderate alcohol use, and with no recreational drug use.

You may not qualify if:

• pregnant women
• history of alcoholism
• infertility treatment
• endometriosis
• pelvic inflammatory disease
• pelvic surgery
• allergy to latex or silicone
• If seeking pregnancy, they were excluded if their partners were working in contact with pesticides, or with history of erectile dysfunction, or history of mumps in adulthood, or with chronic diseases, or with psychological problems.

Sponsors & Collaborators

• MELISA Institute Genomics & Proteomics Research SpA: lead

Study Sites (1)

Clínica Sanatorio Alemán

Chiguayante, Chile

RECRUITING

Related Links

• MELISA Institute

Biospecimen

Retention: SAMPLES WITH DNA

Saliva, urine, blood, cervicovaginal fluid, cervical brushings, umbilical cord blood and placenta.

MeSH Terms

Conditions

Abortion, Spontaneous

Condition Hierarchy (Ancestors)

Pregnancy Complications; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases

Study Officials

• Elard S Koch

  MELISA Institute Genomics & Proteomics Research SpA

  STUDY DIRECTOR

Central Study Contacts

Elard S Koch

CONTACT

+56 41 246 7242; ekoch@melisainstitute.org

Patricio A Alcaino

CONTACT

+56 41 246 7242; palcaino@melisainstitute.org

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: OTHER
• Sponsor Type: INDUSTRY
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Head of research

Study Record Dates

• First Submitted: January 8, 2026
• First Posted: January 22, 2026
• Study Start: July 11, 2017
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): December 1, 2027
• Last Updated: April 29, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL
• Time Frame: January 2027 - December 2028
• Access Criteria: The protocol data and results will be deposited in appropriate public repositories.

Locations

CL (1)