Fetal ultrasound parameters: Reference values for a local perspective

Abstract

Background: Fetal biometry, with the help of ultrasonography (USG) provides the most reliable and important information about fetal growth and well-being. Frequently used parameters for fetal measurements by this method are the biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur length (FL). These fetal dimensions depend upon the racial demographic characteristics, nutrition, genetics and many more environmental factors of a particular population. Aims: The purpose of the present investigation was to define and analyze these fetal biometric parameters in our local population and to compare them with the given norms. Methods: This cross-sectional study with convenience sampling was conducted on a total of 425 fetuses with a period of gestation between 18 to 38 weeks. Descriptive statistics was used to calculate the mean with standard deviation and 95% confidence interval (CI) for each fetal parameter in each gestational week. Results: Mean of BPD and FL in our population are similar to the mean values given by Hadlock throughout the pregnancy, except near the end of the third trimester where our population shows a slightly lower range of mean values. HC and AC fall below the lower range of Hadlock as early as 24 weeks of pregnancy. Conclusions: Fetal biometric parameters in the studied population are at the lower range of established nomograms by Hadlock on white fetuses, more so with the progression of pregnancy.

Comparison of first trimester dating methods for gestational age estimation and their implication on preterm birth classification in a North Indian cohort

“…This is consistent with the pattern observed in a recent study from a Zambian cohort [ 26 ]. The Hadlock formula for USG-based estimation of GA was developed on a Caucasian population and has been used for several decades globally [ 12 ]. We developed and tested population-specific dating formula to estimate GA in an Indian setting.…”

“…The USG method is based on foetal biometry using crown-rump length (CRL) in the first trimester. Several formulae exist to estimate GA using CRL, including Hadlock formula [ 11 ], based on a US population-based study widely used in India [ 12 ]. However, the choice of dating formula might influence dating accuracy, as these formulae have been developed from studies that differed both in the study population and study design [ 13 ].…”

Ultrasonographic Measurement of Placental Thickness and its Correlation with Gestational Age and Fetal Weight

“…These parameters are considered 'gold standard' as they assess the GA with highest degree of accuracy in conjunct. 4 Wolfson et al found biparietal diameter not a reliable parameter in the fetuses with premature rupture of the membranes. 5 Nyberg and Finberg suggested an alternative method in such cases to measure placental thickness which is corresponding to the gestational age.…”

Ultrasonographic estimation of gestation age and growth pattern of foetuses in second trimester of pregnancy by multiple growth parameters

“…Among the various fetal parameters, the parameters that are predominantly incorporated to estimate the GA includes-measurement of gestational sac, crown rump length (CRL), fetal biparietal diameter (BPD), femur length (FL), abdominal circumference (AC) and head circumference (HC). 4 However, the most often considered parameters in the second and third trimester of pregnancy are BPD, FL, AC and HC. These parameters are considered as the gold standard.…”

“…These parameters are considered as the gold standard. 4 Reference values for these four parameters by ultrasound were first detailed by Hadlock on the populaces of developed nations. [5][6][7][8] Fascinatingly, numerous researchers have worked on numerous population groups and have put forth the reference value concerning their own populations due to the difference from the obtained results.…”