Protective Effect of Lactation Against Gestational Diabetes Mellitus in Subsequent Pregnancies: A Prospective Observational Cohort Study

NCT07624968 | Recruiting

• 1 other identifier: LAC-GDM-2026-01
• Study Type: observational
• Target: 140
• Locations: 1 country
• Sites: 2

Brief Summary

Gestational diabetes mellitus (GDM) is a common metabolic disorder of pregnancy associated with increased maternal and fetal morbidity. Lactation has been suggested to improve maternal glucose metabolism, enhance insulin sensitivity, and reduce the risk of future glucose intolerance. However, evidence regarding the protective effect of lactation on the development of GDM in subsequent pregnancies remains limited. This prospective observational cohort study aims to evaluate the association between lactation and the risk of gestational diabetes mellitus and related pregnancy complications in women who conceive during the lactation period. Routine glycemic markers including fasting plasma glucose, HbA1c, glycosuria, and 75-g oral glucose tolerance test (OGTT) results will be recorded. Ultrasonographic findings including fetal abdominal circumference percentile, estimated fetal weight percentile, and amniotic fluid index will also be assessed. The study will investigate whether lactation is associated with a reduced risk of GDM, fetal macrosomia, and polyhydramnios in subsequent pregnancies.

Conditions

Gestational Diabetes Mellitus (GDM); Lactating Mother

Keywords

Gestational Diabetes Mellitus,Lactation,Breastfeeding,Glucose Metabolism,Maternal Health

Outcome Measures

Primary Outcomes (1)

• Incidence of Gestational Diabetes Mellitus

  Occurrence of gestational diabetes mellitus diagnosed by the 75-g oral glucose tolerance test performed between 24 and 28 weeks of gestation.

  24-28 weeks of gestation

Secondary Outcomes (1)

• Fetal Macrosomia

  From second trimester until delivery

Other Outcomes (1)

• Polyhydramnios

  From second trimester until delivery

Study Arms (1)

Pregnant Women During Lactation Period

Singleton pregnant women aged 18-50 years who conceived during the lactation period and were followed at participating obstetrics and gynecology clinics.

Eligibility Criteria

• Age: 18 Years - 50 Years
• Gender Eligibility Details: Individuals who self-identify as women and are pregnant during the lactation period are eligible to participate in the study.
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)
• Sampling Method: Non-Probability Sample

Study Population

Pregnant individuals aged 18-50 years who conceived during the lactation period and are receiving antenatal care at participating obstetrics and gynecology clinics. Participants must have singleton pregnancies and available routine glycemic and ultrasonographic follow-up data. The study population represents women undergoing standard prenatal care in a tertiary care and secondary care hospital setting.

You may qualify if:

• Pregnant individuals aged 18 to 50 years.
• Singleton pregnancy.
• Conception during the lactation period.
• Follow-up at Prof. Dr. Cemil Taşcıoğlu City Hospital or Esenyurt Necmi Kadıoğlu State Hospital.
• Availability of glycemic parameters including fasting plasma glucose, HbA1c, glycosuria, and 75-g oral glucose tolerance test (OGTT) results.
• Availability of routine ultrasonographic measurements including fetal abdominal circumference percentile (AC), estimated fetal weight percentile (EFW), and amniotic fluid index (AFI).

You may not qualify if:

• Age below 18 years.
• Age above 50 years.
• Multiple pregnancy.
• Known chronic systemic disease or pre-existing diabetes mellitus.
• Missing clinical, laboratory, or ultrasonographic data.

Sponsors & Collaborators

• Prof. Dr. Cemil Tascıoglu Education and Research Hospital Organization: lead

Study Sites (2)

Prof. Dr. Cemil Taşcıoğlu City Hospital

Istanbul, 34384, Turkey (Türkiye)

RECRUITING

Esenyurt Necmi Kadıoğlu State Hospital

Istanbul, 34517, Turkey (Türkiye)

RECRUITING

MeSH Terms

Conditions

Diabetes, Gestational

Condition Hierarchy (Ancestors)

Pregnancy Complications; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Diabetes Mellitus; Glucose Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases; Endocrine System Diseases

Central Study Contacts

Burak D AYDOGDU, MD, OB/GYN

CONTACT

+90 5396182228; burakd.1992@hotmail.com

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: May 29, 2026
• First Posted: June 3, 2026
• Study Start: January 15, 2026
• Primary Completion (Estimated): December 31, 2027
• Study Completion (Estimated): December 31, 2027
• Last Updated: June 3, 2026

Record last verified: 2026-05

Data Sharing

• IPD Sharing: Will not share

Locations

TU (2)