Longitudinal first-trimester reference charts for crown to rump length and related fetal structures in a

Jasmin M de Groot1,2, Romy Gonçalves1,2, Mireille C Schipper1,2

  • 1The Generation R Study Group, Erasmus University Medical Center, Rotterdam, the Netherlands.

Insights

This study provides crucial first-trimester fetal growth charts, establishing reference centiles for crown rump length and sac development. These findings aid in assessing normal early fetal development and identifying potential abnormalities.

Area of Science:

  • Embryology and Fetal Development
  • Reproductive Medicine
  • Biostatistics

Background:

  • Early fetal growth is vital for long-term health, yet detailed knowledge of first-trimester development is limited.
  • Understanding normal and abnormal development of fetal structures in the first trimester is crucial for early detection of growth issues.

Purpose of the Study:

  • To construct population distribution centiles for gestational age in the first trimester.
  • To establish reference centiles for fetal crown-rump length, yolk sac, gestational sac, and amniotic sac between 6 and 13 weeks of gestation.

Main Methods:

  • Utilized ultrasound data from 3464 assessments in 1609 pregnant women with known last menstrual period (LMP) and regular cycles.
  • Employed Generalized Additive Modeling for Location, Size and Shape (GAMLSS) to estimate distribution and reference centiles.
  • Measurements included crown-rump length, and yolk, amniotic, and gestational sac dimensions and volumes.

Main Results:

  • Developed distribution centiles for pregnancy dating using first-trimester crown-rump length (10-70 mm).
  • Generated reference centiles (5th-95th) for fetal crown-rump length and sac measurements from 6+0 to 12+6 weeks gestation.
  • Observed a near-linear growth trajectory for length and diameter outcomes, with reliable centiles between 6+0 and 12+6 weeks.

Conclusions:

  • Created descriptive population distribution centiles for LMP-based gestational age and reference charts for key fetal structures.
  • These charts are intended for use in clinical and population-based settings for first-trimester assessment.
  • Users should consider the source population and potential biases when interpreting the generated charts.
Abstract

Related Concept Videos