Early PregnancyEARLY-PREGNCT07358026
EARLY-PREG: A Preconception Cohort Study Based on Counterfactuals to Study Maternal-Embryonic Molecular Interactions
An observational study of Early Pregnancy and Early Pregnancy Loss, run by MELISA Institute Genomics & Proteomics Research SpA at 1 site in Chile.
Trial 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… Read more about this study
- Who is it for?
- Ages 18 to 40 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- Early Pregnancy, Early Pregnancy Loss, Childbirth
- What is being tested?
- EMBRYO EXPOSURE
- How many people
- 223 participants
- Where
- 1 siteChile
- Study dates
- 11 Jul 2017to Dec 2027
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 40 years
- Women only
- Healthy volunteers accepted
- Adult
Study population: Women visiting gynaecologists, and midwives in private practices, public hospitals, and Family Health Centres (CESFAMs) in the Biobio region of Chile.
Who may be able to join
- 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.
Who cannot join
- 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.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
About this study
Official title: EARLY-PREG: A Preconception, Longitudinal, Bidirectional, and Counterfactual Cohort Study of Women Seeking Pregnancy, Designed to Investigate Maternal-Embryonic Molecular Interactions During the Peri-implantation Window
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.
Read the detailed description
Successful pregnancy depends on a coordinated exchange of signals between the early embryo and the mother. This complex process begins immediately after fertilisation, during the pre-implantation period. Although it plays a critical role in preparing the maternal environment for pregnancy, the mechanisms behind this communication remain incompletely understood.
The unique 'dialogue' between the embryo and the mother is a bidirectional exchange known as embryo-maternal crosstalk. Evidence indicates that this interaction, mediated by molecular signals present in uterine fluid, supports appropriate embryo implantation and modulates the maternal immune system to facilitate tolerance of the developing embryo.
To date, the majority of knowledge in this field has been derived from animal models and in vitro studies, which may not fully represent the physiology of spontaneous human conception. The EARLY-PREG preconception open cohort has been established to address this gap by characterising embryo-maternal crosstalk in vivo. This study follows healthy women who are trying to become pregnant, following them from before conception through the first two weeks of a natural conception, with continued follow-up into pregnancy and childbirth.
Daily collection of a range of biological samples - including saliva, urine, blood, cervicovaginal fluid and cervicovaginal brushings - is undertaken during key phases of the menstrual cycle. These samples are processed, preserved and stored in a dedicated biorepository for subsequent analysis using omics-based approaches.
- Conditions
- Early Pregnancy, Early Pregnancy Loss, Childbirth, Healthy, Pregnancy
- Being tested
- EMBRYO EXPOSURE
- Keywords
- longitudinal study, counterfactual design, embryo-mother crosstalk, biorepository, maternal fluids, menstrual cycle, preconception open cohort
- Medical subject headings
- Abortion, Spontaneous
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
EMBRYO EXPOSUREOther
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).
| Study group | Role | What they receive |
|---|---|---|
| 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. Receives: 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. |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: 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.
Measured: 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.
Measured: 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.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Jan 2026
- Study start11 Jul 2017
- Primary completionDec 2026 (estimated)
- Study completionDec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Early PregnancyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Other
- Enrolment
- 223 participants (estimated)
Sponsor and investigators
- Lead sponsor
- MELISA Institute Genomics & Proteomics Research SpA
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Principal investigator, Elard Koch, PhD, MELISA Institute Genomics & Proteomics Research SpA
- Investigators
- Elard S Koch, Study director, MELISA Institute Genomics & Proteomics Research SpA
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07358026
- Sponsor's protocol ID
- 17-03-06
- Other IDs
- MEL109112011, MEL109112011R4, MEL109112011R5, MEL131032017R1, MEL205062018, REH042024-01
- Acronym
- EARLY-PREG
- Status last verified
- Jan 2026
- First submitted
- 8 Jan 2026
- Last updated
- 29 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: All IPD information underlying the results of a publication will be shared with the sole exception of sensitive information that could reveal a person's identity.
Study at a glance
From the registry record, last updated by the sponsor on 29 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- EARLY-PREG: A Preconception, Longitudinal, Bidirectional, and Counterfactual Cohort Study of Women Seeking Pregnancy, Designed to Investigate Maternal-Embryonic Molecular Interactions During the Peri-implantation Window
- ClinicalTrials.gov ID
- NCT07358026
- Acronym / sponsor ID
- EARLY-PREG / 17-03-06
- Conditions
- Early Pregnancy, Early Pregnancy Loss, Childbirth, Healthy, Pregnancy
- Keywords
- longitudinal study, counterfactual design, embryo-mother crosstalk, biorepository, maternal fluids, menstrual cycle, preconception open cohort
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 223 participants (estimated)
- Lead sponsor
- MELISA Institute Genomics & Proteomics Research SpAIndustry (pharma, biotech, devices)
- Study start
- 11 Jul 2017 (actual)
- Primary completion
- Dec 2026 (estimated)
- Study completion
- Dec 2027 (estimated)
- First posted
- 22 Jan 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
Successful pregnancy depends on a coordinated exchange of signals between the early embryo and the mother. This complex process begins immediately after fertilisation, during the pre-implantation period. Although it plays a critical role in preparing the maternal environment for pregnancy, the mechanisms behind this communication remain incompletely understood.
The unique 'dialogue' between the embryo and the mother is a bidirectional exchange known as embryo-maternal crosstalk. Evidence indicates that this interaction, mediated by molecular signals present in uterine fluid, supports appropriate embryo implantation and modulates the maternal immune system to facilitate tolerance of the developing embryo.
To date, the majority of knowledge in this field has been derived from animal models and in vitro studies, which may not fully represent the physiology of spontaneous human conception. The EARLY-PREG preconception open cohort has been established to address this gap by characterising embryo-maternal crosstalk in vivo. This study follows healthy women who are trying to become pregnant, following them from before conception through the first two weeks of a natural conception, with continued follow-up into pregnancy and childbirth.
Daily collection of a range of biological samples - including saliva, urine, blood, cervicovaginal fluid and cervicovaginal brushings - is undertaken during key phases of the menstrual cycle. These samples are processed, preserved and stored in a dedicated biorepository for subsequent analysis using omics-based approaches.
Study design
- Observational model
- Cohort
- Time perspective
- Other
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| CONCEPTION CYCLE | – | Other: EMBRYO EXPOSUREConception 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. |
| 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. |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- Women visiting gynaecologists, and midwives in private practices, public hospitals, and Family Health Centres (CESFAMs) in the Biobio region of Chile.
Key inclusion criteria (7 listed)
- 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)
Key exclusion criteria (8 listed)
- pregnant women
- history of alcoholism
- infertility treatment
- endometriosis
- pelvic inflammatory disease
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| EMBRYO EXPOSUREThe 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). | Other | CONCEPTION CYCLE |
Primary outcome
Number of menstrual cycles leading to full-term pregnancies
Time frame: 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.
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.
Number of menstrual cycles not leading to pregnancy
Time frame: From enrollment for up to six menstrual cycles (each cycle ranges from 21-35 days) or until pregnancy occurs, whichever occurs first.
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.
Number of menstrual cycles leading to early pregnancy loss
Time frame: 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.
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.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 29 Apr 2026.
- MELISA InstituteLink provided by the sponsor.
- Individual participant dataSharing planned: Yes. All IPD information underlying the results of a publication will be shared with the sole exception of sensitive information that could reveal a person's identity.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Elard S Koch study director
MELISA Institute Genomics & Proteomics Research SpA
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Early Pregnancy and Early Pregnancy Loss, run by MELISA Institute Genomics & Proteomics Research SpA at 1 site in Chile.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 29 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Chile. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Elard S Koch (+56 41 246 7242, ekoch@melisainstitute.org), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of menstrual cycles leading to full-term pregnancies (time frame: 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.). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 29 Apr 2026.