Serial Body Composition Measurements by PEAPOD (SBMP)

Body Composition at Birth and Its Evolution Over the First 6 Months in Neonates Using Air-displacement Plethysmography (PEAPOD Machine): A Prospective Longitudinal Matched Case-control Study in a Low-income Setting

Birth weight alone is not precise enough to explain the nutritional status of a newborn baby. For SGA babies (born smaller than they should be for birth age and sex) a sophisticated machine called a PEAPOD can calculate the percentage of body fat, fat mass and fat-free mass. The PEAPOD does these measurements by moving air around a baby placed on a scale inside a Pod. The procedure is quick (average 7 minutes), accurate, safe and useful to 6 months of age. The investigators want to understand if there are clues in the body composition of babies born to small compared to babies of the right size that point to why born too small have increased risk of heart and blood vessel problems linked to issues like diabetes and obesity, later in life. A type of study called "matched case-control" could help us investigate mother factors that are associated with being born too small. Cases (SGA) will be matched with controls (AGA, a baby born not too small and not too large) based on sex, weeks of age at birth (±1 week), number of births the mother has had (same parity). Information about the study will be given in pregnancy. If consent is provided blood samples (mother and cord) will be collected at birth. Small amount of blood will be taken from mother and baby one time at birth, 1, 2, 3, 4, 5 and 6 months; and babies will attend for 7 PEAPOD measurements unless birth weight >6.0kg is reached first. Additionally, mother's breast milk will be collected. These will be used to measure different molecules in the blood related to health and disease. With the data from this study, the investigators may be able to provide better recommendations during pregnancy that can help optimize baby and infant nutritional status and adult health outcomes.

Study Overview

• Status: Not yet recruiting
• Conditions: Body Composition; Infant, Small for Gestational Age; Infant Growth
• Intervention / Treatment: Device: PEAPOD Air Displacement Plethysmography Device

Detailed Description

This study aims to investigate body composition at birth and its evolution over the first six months of life in neonates using air-displacement plethysmography (PEAPOD). Traditional anthropometric measures such as birth weight and length provide limited information on neonatal nutritional status, as they do not distinguish between fat mass and fat-free mass. Understanding early body composition may offer important insights into infant growth patterns and long-term health outcomes, including risks of metabolic and cardiovascular diseases.

This is a prospective longitudinal matched case-control study conducted at the Mawker Thai Clinic, Shoklo Malaria Research Unit (SMRU), along the Thailand-Myanmar border. The study will recruit 300 mother-infant pairs, including 150 small-for-gestational-age (SGA) neonates and 150 appropriate-for-gestational-age (AGA) neonates. Cases and controls will be matched based on sex, gestational age (±1 week), and parity.

Following informed consent obtained during pregnancy, baseline maternal data will be collected from routine antenatal care. After delivery, neonatal eligibility will be confirmed, and study procedures will begin within 24-48 hours of birth. Body composition measurements will be performed using the PEAPOD device, a validated, non-invasive method for assessing fat mass, fat-free mass, and percentage body fat in infants.

Participants will be followed monthly up to six months postpartum (or until the infant reaches 6.0 kg, the upper limit for PEAPOD measurement). At each visit, both maternal and infant assessments will be conducted. These include anthropometric measurements, body composition assessments, and collection of biological samples such as maternal venous blood, umbilical cord blood, capillary blood samples, and maternal breast milk. Laboratory analyses will include haematological parameters and nutritional biomarkers relevant to maternal and infant health.

The primary objective is to compare longitudinal changes in body composition between SGA and AGA infants during the first six months of life. Secondary objectives include identifying maternal and fetal factors associated with neonatal and infant body composition, including maternal nutritional status, gestational weight gain, metabolic conditions, and breast milk composition.

This study will provide important evidence on early-life body composition trajectories in a resource-limited setting and may inform strategies to improve maternal and infant health, nutritional interventions, and long-term disease prevention.

• Study Type: Observational
• Enrollment (Estimated): 300

Contacts and Locations

• Study Contact: Name: Dr Nay Win Tun, MBBS; Phone Number: +66800273370; Email: naywintun@shoklo-unit.com
• Study Contact Backup: Name: Htet Htet Aung, BA; Phone Number: +66828082412; Email: htethtetaung@tropmedres.ac

Study Locations

• Thailand
  • Changwat Tak
    • Tak, Changwat Tak, Thailand
      • Mawker Thai Clinic, Shoklo Malaria Research Unit (SMRU)
      • Contact: Dr Nay Win Tun, MBBS; Phone Number: +66800273370; Email: naywintun@shoklo-unit.com
      • Principal Investigator: Prof Rose McGready
      • Sub-Investigator: Prof Francois H. Nosten
      • Sub-Investigator: Dr Sue J Lee
      • Sub-Investigator: Dr Nay Win Tun
      • Sub-Investigator: Dr Aung Myat Min
      • Sub-Investigator: Dr Mellie Gilder
      • Sub-Investigator: Dr May Thu Thu Aung
      • Sub-Investigator: Dr Ajjima Thussachan

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: No older than 6 months (Child)
• Accepts Healthy Volunteers: N/A
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Pregnant woman attending for antenatal care or admitted for delivery and their neonates attending at Mawker Thai clinic along the Thailand-Myanmar border. The study population includes both small for gestational age (SGA) and appropriate for gestational age (AGA) neonates and their mothers, representing a resource-limited border population.

Description

Inclusion Criteria:

Pregnant woman

• The pregnant woman who had received a good dating ultrasound scan less than 24 weeks' gestation and maternal age would be ≥ 18 years old.
• Willing and able to provide informed consent.
• Able to attend monthly follow-up visits.

Neonates

• Normal, single-baby pregnancy (singleton) born at term at Mawker Thai clinic.

  • Neonate eligibility can only be confirmed after delivery.

Exclusion Criteria:

Pregnant woman

• Families residing far from the study site and unable to commit to follow-up. Neonates*

• Baby born requiring admission to the special care baby unit (SCBU).

  • Neonate eligibility can only be confirmed after delivery.

Study Plan

How is the study designed?

Design Details

• Observational Models: CASE_CONTROL
• Time Perspectives: PROSPECTIVE

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Small for Gestational Age (SGA) Neonates; Neonates classified as small for gestational age (SGA), defined as birth weight below the 10th percentile for gestational age. Participants will undergo non-invasive body composition measurements using air-displacement plethysmography (PEAPOD) and follow-up assessments at monthly intervals up to six months of age (or until reaching 6.0 kg). Additional study procedures include anthropometric measurements and collection of biological samples (maternal blood, cord blood, infant capillary blood, and breast milk) for laboratory analyses.	Device: PEAPOD Air Displacement Plethysmography Device; The PEAPOD air displacement plethysmography system is a non-invasive device used to measure infant body composition, including fat mass, fat-free mass, and percentage body fat. The measurement is performed by placing the infant in a calibrated chamber for a short duration, during which body volume and mass are assessed. The procedure is safe, painless, and does not involve radiation or invasive techniques. In this study, the device is used solely for observational measurement of body composition and not as a therapeutic intervention.; Other Names: PEAPOD Infant Body Composition Device
Appropriate for Gestational Age (AGA) Neonates; Neonates classified as appropriate for gestational age (AGA), defined as birth weight between the 10th and 90th percentile for gestational age. Participants will undergo the same study procedures as the SGA group, including non-invasive body composition measurements using PEAPOD and follow-up assessments at monthly intervals up to six months of age (or until reaching 6.0 kg), along with anthropometric measurements and collection of biological samples for laboratory analyses.	Device: PEAPOD Air Displacement Plethysmography Device; The PEAPOD air displacement plethysmography system is a non-invasive device used to measure infant body composition, including fat mass, fat-free mass, and percentage body fat. The measurement is performed by placing the infant in a calibrated chamber for a short duration, during which body volume and mass are assessed. The procedure is safe, painless, and does not involve radiation or invasive techniques. In this study, the device is used solely for observational measurement of body composition and not as a therapeutic intervention.; Other Names: PEAPOD Infant Body Composition Device

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Body composition changes - Fat mass in neonates with small for gestational age (SGA) and appropriate for gestational age (AGA) at birth and during the first 6 months of life	Fat mass (kg) measured using air displacement plethysmography (PEAPOD) at birth and during follow-up visits to compare between small for gestational age (SGA) and appropriate for gestational age (AGA) infants	At birth, 1, 2, 3, 4, 5 and 6 months of life (unless body weight >6.0kg is reached first)
Body composition changes - Fat-free mass in neonates with small for gestational age (SGA) and appropriate for gestational age (AGA) at birth and during the first 6 months of life	Fat-free mass (kg) measured using PEAPOD at birth and during follow-up visits to compare between SGA and AGA infants	At birth, 1, 2, 3, 4, 5 and 6 months of life (unless body weight >6.0kg is reached first)
Percentage body fat in SGA and AGA infants	Percentage body fat (%) measured using PEAPOD at birth and during follow-up visits to compare between SGA and AGA infants	At birth, 1, 2, 3, 4, 5 and 6 months of life (unless body weight >6.0kg is reached first)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maternal First-Trimester Body Mass Index (BMI)	Maternal first-trimester BMI (kg/m²) calculated from weight and height recorded during antenatal care	Baseline (antenatal records)
Maternal Gestational Weight Gain	Maternal gestational weight gain (kg) calculated from antenatal weight measurements	Baseline (antenatal records)
Gestational Diabetes Mellitus Status	Presence or absence of gestational diabetes mellitus documented in maternal clinical records	Baseline (antenatal records)
Maternal Anaemia	Presence or absence of maternal anaemia determined from maternal haemoglobin measurements	Baseline to maximum 6 months postpartum
Maternal HbA1c Concentration	Maternal glycated haemoglobin (HbA1c) percentage (%) measured from maternal blood samples	Delivery and 2 months postpartum
Breast Milk Creamatocrit	Creamatocrit percentage (%) measured from maternal breast milk samples	At birth to maximum 6 months postpartum
Breast Milk Sodium Concentration	Sodium concentration (mmol/L) measured from maternal breast milk samples	At birth to maximum 6 months postpartum
Breast Milk Proteomic Profile	Proteomic profile of maternal breast milk measured using MALDI-TOF analysis	Delivery and monthly postpartum until 6 months

Collaborators and Investigators

• Sponsor: Shoklo Malaria Research Unit
• Collaborators: Mahidol University; Mahidol Oxford Tropical Medicine Research Unit
• Investigators: Principal Investigator: Prof Rose McGready, Shoklo Malaria Research Unit

Study record dates

Study Major Dates

• Study Start (Estimated): December 1, 2026
• Primary Completion (Estimated): October 31, 2028
• Study Completion (Estimated): October 31, 2028

Study Registration Dates

• First Submitted: April 9, 2026
• First Submitted That Met QC Criteria: November 3, 2026
• First Posted (Actual): November 9, 2026

Study Record Updates

• Last Update Posted (Actual): November 9, 2026
• Last Update Submitted That Met QC Criteria: November 3, 2026
• Last Verified: November 1, 2026

More Information

Terms related to this study

• Keywords: Thailand-Myanmar border; Small for gestational age (SGA); Neonatal body composition; PEAPOD; Appropriate for gestational age (AGA); Air Displacement Plethysmography
• Other Study ID Numbers: SBMP

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

IPD Plan Description

Individual participant data (IPD), including de-identified clinical, anthropometric, laboratory, and body composition data collected during the study, will not be made publicly available. Data collected in this study involve sensitive information from mothers and neonates in a vulnerable population, and sharing will be restricted to protect participant confidentiality. De-identified data may be made available upon reasonable request, subject to review and approval by the study investigators and relevant institutional authorities, and in accordance with data sharing agreements and applicable ethical and regulatory requirements.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No