Protective Effect of Lactation Against Gestational Diabetes Mellitus in Subsequent Pregnancies: A Prospective Observational Cohort Study
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- This is an observational study: the protocol does not assign a study treatment.
- Who it may be relevant to
- Registry conditions: Gestational Diabetes Mellitus (GDM), Lactating Mother. Basic parameters: 18 years — 50 years · Female.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Turkey (Türkiye)
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Official title
Protective Effect of Lactation Against Gestational Diabetes Mellitus in Subsequent Pregnancy: A Prospective Observational Cohort Study
Overview
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.
Detailed description
Gestational diabetes mellitus (GDM) is one of the most common metabolic complications of pregnancy and is associated with adverse maternal and neonatal outcomes, including fetal macrosomia, polyhydramnios, cesarean delivery, and future development of type 2 diabetes mellitus. Early identification of women at increased risk of GDM is essential for optimizing antenatal care and improving pregnancy outcomes.
Lactation has been reported to exert beneficial metabolic effects through increased glucose utilization, improved insulin sensitivity, and facilitation of postpartum weight loss. Previous studies have suggested that breastfeeding may reduce the long-term risk of type 2 diabetes in women with a history of GDM. However, evidence regarding the protective effect of lactation on the occurrence of gestational diabetes mellitus in subsequent pregnancies remains limited.
The present prospective observational cohort study aims to evaluate the relationship between lactation and the development of gestational diabetes mellitus in women who become pregnant during the lactation period. Pregnant women aged 18-50 years with singleton pregnancies who attend the participating obstetrics and gynecology clinics will be enrolled. Routine laboratory parameters obtained during antenatal care, including fasting plasma glucose, HbA1c, glycosuria, and 75-g oral glucose tolerance test (OGTT) results, will be recorded.
In addition, routine ultrasonographic measurements, including fetal abdominal circumference percentile (AC), estimated fetal weight percentile (EFW), and amniotic fluid index (AFI), will be collected during the second and third trimesters. Maternal demographic and obstetric characteristics, including age, gravidity, parity, abortion history, and educational status, will also be documented.
The primary objective of the study is to determine whether lactation is associated with a reduced risk of gestational diabetes mellitus. Secondary objectives include evaluating the association between lactation and pregnancy complications related to altered glucose metabolism, including fetal macrosomia and polyhydramnios. The findings of this study may contribute to a better understanding of the metabolic effects of lactation and provide evidence for strategies aimed at reducing the burden of gestational diabetes mellitus in future pregnancy.
Primary outcome measures
- Incidence of Gestational Diabetes Mellitus [Time frame: 24-28 weeks of gestation]
Secondary outcome measures (1)
- Fetal Macrosomia [Time frame: From second trimester until delivery]
Eligibility criteria
Inclusion criteria
- 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).
Exclusion criteria
- 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.
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: Yes
Study design
- Observational model
- Cohort
Study locations
Turkey (Türkiye) · 2 centers
- Prof. Dr. Cemil Taşcıoğlu City Hospital — Istanbul
- Esenyurt Necmi Kadıoğlu State Hospital — Istanbul
Identifiers
NCT: NCT07624968 · LAC-GDM-2026-01