The Application of First‑Trimester Volumetry in Predicting Pregnancy Complications

Abstract

The application of first trimester volumetry in predicting pregnancy complications is a promising and interesting field in Obstetrics and Radiology. This was a descriptive review of first trimester volumetry in predicting pregnancy complications over a period of 6 months (January 1^st, 2013 to June 30^th, 2013). A search of literature on first trimester volumetry published in English was conducted. Relevant materials on first trimester volumetry were selected. Placenta volumes (PV) and embryo volume/fetal volume ratios in the first trimester are correlated with crown rump length (CRL) or gestational age (GA). Measurement of PV or placental quotient (PV/CRL ratio) is an early assessment to identify impaired trophoblast invasion and predict subsequent development of intrauterine growth restriction (IUGR) or pre‑eclampsia (PE). In early onset IUGR due to triploidy, or trisomy 13 or 18, a larger deficit in fetal volume is observed compared to CRL. In obstetric sonography, standardization of the 3D volumetric methodology is needed to improve reproducibility of measurement. The accuracy of these measurements is uncertain and current applicability to practice is not fully accepted, therefore, the current methods are yet to be standardized and general applicability is uncertain. Volumetry holds a good promise as an extra method for predicting IUGR, PE, aneuploidy, miscarriages, or stillbirth but lack of standardization currently limits its applicability.

Keywords: 3D ultrasound, first trimester, pregnancy complications, volumetry