1. Introduction: Why is it important to know the gestational age in a newborn?

The importance of differentiating between pre-term and term newborns [1]

Preterm birth complications are estimated to be responsible for 35% of the world’s annual neonatal deaths. Furthermore, these complications are the second most common cause of death after pneumonia in children under 5 years old.

Preterm birth increases the risk of death due to neonatal infections and in almost all countries, preterm birth is the leading cause of child deaths as well as ther is an increased risk of cerebral palsy, impaired learning, visual disorders, and of chronic disease in adulthood.

The economic and social cost of preterm birth is high in terms of neonatal intensive care and ongoing health-care and educational needs.

Pediatric radiologists and lack of clinical information[1]

The accurate dating of pregnancy is critically important for pregnancy management. Ultrasound gave clinicians a method to measure the fetus to estimate gestational age (GA). But knowing the gestational age is not only important before pregnancy but also after it, specially during the first days of life. 

Pediatric radiologists usually report initial plain chest films of newborns admitted to the neonatal intensive care unit (NICU) without having this critical information. Digital image reading may be misleading as displayed image size does not closely follow gestational age.

The precise gestational age assessment helps radiologists to suspect several pathologies (surfactant deficiency disorder, haemorrhage, meconium aspiration syndrome, or intrauterine growth restriction) dependent on premature, term, or post-term gestational age.

Current known measurements on fetus: Estimation of gestational age based on US Findings [2][3][4][5]

It is well known that dating a pregnancy using ultrasound measurements is clinically superior to using menstrual dating. This demonstrates the reliability of imaging techniques for estimating the gestational age during pregnancy. Ultrasound biometric measurements determine gestational age based on the assumption that the size of the embryo or fetus is consistent with its age.

First trimester: During the first-trimester, the crown-rump length is the best parameter for determining gestational age. Direct measurement of the CRL provides the most accurate estimate of gestational age once the embryo is clearly seen. Between the 12th and 14th weeks, crown-rump length and biparietal diameter are similar in accuracy.

Second and Third Trimester: A combination of multiple biometric parameters (biparietal diameter, head circumference, abdominal circumference, and femur length) is used to determine gestational age, rather than a single parameter.

2. Objective of this scientific exhibit

The purpose of this scientific exhibit is to describe a reliable and quick method to estimate the gestational age by measurements taken in A-P chest x-ray exams of  newborn infants, full-term, critically ill and premature, admitted to a neonatal intensive care unit (NICU). The method may provide this critical information frequently unavailable while reporting initial studies.