Protein and Amino Acid Requirements during Pregnancy.
Level 5 - mechanism / opinion, no new human data
Narrative review summarizing previous tracer studies and animal models
PubMed 27422521 · doi:10.3945/an.115.011817
What was done
This review evaluated dietary protein and amino acid requirement determinations across pregnancy, comparing standard factorial estimates with metabolic data obtained using the minimally invasive indicator amino acid oxidation (IAAO) method in women during early (~16 weeks) and late (~36 weeks) gestation, alongside indispensable amino acid requirement data from swine models.
What was found
Current Estimated Average Requirement and RDA recommendations set uniform values of 0.88 and 1.1 g · kg(-1) · d(-1) across all stages of pregnancy. In contrast, IAAO measurements identified average requirements of 1.2 g · kg(-1) · d(-1) in early pregnancy (~16 wk) and 1.52 g · kg(-1) · d(-1) in late pregnancy (~36 wk), representing ~14-18% of total energy intake. Swine models showed that requirements for several indispensable amino acids increase dramatically in late compared to early gestation.
Why it matters
Current single-value dietary recommendations across all gestational stages may underestimate protein needs during the third trimester when maternal and fetal tissue growth peaks.
Limits
The abstract describes a narrative review and does not report sample sizes, confidence intervals, or study quality metrics for the referenced IAAO studies. Evidence for specific indispensable amino acid requirements is derived from swine models rather than direct human trials.
Cited by
- supports Pregnant women require approximately 1.6 grams of protein per kilogram of body weight per day in the third trimester.