How much leucine pregnant women need.

Dietary Leucine Requirements During Early and Late Gestation in Healthy Pregnant Women

Not applicable Interventional University of British Columbia · NCT07437248

This project will test how much leucine pregnant women need in early and late pregnancy by giving prepared meals and collecting breath, urine, and one blood sample.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment40 (estimated)
Ages20 Years to 40 Years
SexFemale
SponsorUniversity of British Columbia Academic / other
Locations1 site (Vancouver, British Columbia)
Trial IDNCT07437248 on ClinicalTrials.gov

What this trial studies

Researchers will use the indicator amino acid oxidation (IAAO) technique to determine dietary leucine requirements in healthy women with singleton pregnancies at 11–20 weeks (early) and 31–40 weeks (late) gestation. Participants will eat carefully prepared meals with controlled leucine intake and provide breath and urine samples and one blood draw so investigators can track leucine metabolism. The study compares measurements from the two gestational windows to see whether leucine needs change across pregnancy. Results are intended to inform pregnancy-specific nutrition recommendations to support maternal and fetal health.

Who should consider this trial

Good fit: Healthy pregnant women aged 20–40 with a singleton pregnancy at either 11–20 weeks or 31–40 weeks who can attend visits at the Vancouver research site are ideal candidates.

Not a fit: Women with multiple gestations, significant chronic medical conditions, age outside 20–40 years, or who cannot attend the Vancouver site are unlikely to benefit from participating.

Why it matters

Potential benefit: If successful, the results could lead to clearer dietary recommendations that better support maternal muscle health and fetal growth during pregnancy.

How similar studies have performed: IAAO and related amino acid requirement studies have been used in pregnancy and have shown differing needs for some amino acids, but direct data on leucine across pregnancy are limited.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Pregnant women aged 20-40 years. (This age range represents typical reproductive age and minimizes potential confounding effects related to adolescent growth or age-associated metabolic changes.)
* Singleton pregnancy. (Restricting participation to singleton pregnancies reduces variability in nutrient requirements and metabolic demands associated with multiple gestations.)
* Gestational age of either 11-20 weeks (early gestation) or 31-40 weeks (late gestation).

(These time points represent physiologically distinct stages of pregnancy, allowing comparison of leucine requirements across early and late gestation.)

* Participants who take part in early gestation, can participate in late gestation, if they meet all inclusion criteria.
* Good general health with no acute or chronic medical conditions. (Including only healthy participants minimizes confounding factors that could alter amino acid metabolism and ensures participant safety.)
* Fully ambulatory and able to comply with study procedures. (Participants must be able to attend study visits and complete protocol requirements, including dietary intake and sample collection.)
* Pre-pregnancy body mass index (BMI) between 19 and 28 kg/m² (This range excludes underweight and obese individuals, whose altered protein and amino acid metabolism could affect study outcomes.)
* Carrying a viable pregnancy without known complications at enrollment. (Excluding pregnancy complications at baseline reduces risk to participants and supports accurate assessment of physiological amino acid requirements.)

Exclusion Criteria:

-Pregnancy-related complications (e.g., hyperemesis gravidarum, GDM, hypertension, pre-eclampsia, anemia).

(These conditions may alter metabolism and increase risk, potentially confounding study outcomes.)

* History of adverse pregnancy outcomes (spontaneous abortion or preterm birth). (May reflect underlying physiological factors affecting amino acid metabolism.)
* Multiple gestation pregnancies. (Nutritional and metabolic demands differ from singleton pregnancies.)
* Pregnancy loss within six months of the current pregnancy. (Short intervals may affect maternal nutrient status and metabolic adaptation.)
* Chronic metabolic, cardiovascular, neurological, genetic, or immune disorders. (These conditions may independently affect protein and amino acid metabolism.)
* Clinically significant claustrophobia. (May interfere with study procedures requiring ventilated hood measurements.)
* Use of alcohol, tobacco, or illicit substances during pregnancy. (Substance use affects metabolism and poses maternal and fetal health risks.)
* Gestational weight loss greater than 1.5 kg. (May indicate inadequate nutritional status.)
* Pre-pregnancy BMI outside 19-28 kg/m². (Extremes of BMI are associated with altered protein metabolism.)

Where this trial is running

Vancouver, British Columbia

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions PregnancyDietary AnalysisProteinLeucineAmino AcidStable Isotope
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.