Ultrasound assessment of fetal biparietal diameter and femur length during normal pregnancy in Iranian women

Fetal Humeral Diaphyseal Length in the Second Trimester - A Radiographic Observational Study among Indian Population

Objectives

The present study was performed to provide a normal reference range for humerus diaphysis length at the second trimester of pregnancy in an Indian population.

Materials and Methods

This cross-sectional study was performed on 25 radiographs of aborted normal human fetuses of gestational age (GA) between 13th and 28th weeks. The radiographs were used to measure the maximum length of the humerus using a vernier calliper. Data were collected, tabulated, and statistically analyzed.

Results

The mean diaphyseal length of humerus at the fourth lunar month was 22.18 ± 6.59 mm, and at the seventh lunar month, it was 41.39 ± 10.08 mm. Simple linear regression analysis shows a strongly significant linear relationship of humerus length with GA, biparietal diameter, head circumference, and abdomen circumference.

Conclusion

We have provided a normal reference range for humerus diaphysis length at the second trimester of pregnancy in an Indian population.

Ultrasound Assessment of Fetal Biometry in Iranian Normal Pregnancies

Background

The objective of this study was to provide biometric charts for Iranian fetuses.

Methods

One thousand four hundred and twenty-two women enrolled. Four hundred and eighty-four were in the second trimester of pregnancy and 940 were in the third trimester. Data were presented as mean ± standard deviation for continuous variables. Percentiles (5^th, 50^th, 75^th, and 90^th) reported.

Results

Mean femoral length ranged from 16 to 53 mm in our study in the second trimester and 55-79 mm in the third trimester. Mean biparietal diameter (BPD) for fetuses with in the second trimester was between 14 and 71 and for fetuses in the third trimester was between 74 and 98 mm. Mean abdominal circumference (AC) in our cases with gestational age between 14 and 41 ranged between 86 and 365 mm.

Conclusions

We have provided normal reference ranges and percentiles for BPD, AC, femur length, and weight during the second and third trimester of pregnancy in an Iranian population.

Comparison of radiographic femur measurements in stillbirths and neonatal deaths to ultrasound measurements in ongoing pregnancies

Identifying growth abnormalities in stillbirths is clinically useful but complicated by maceration. This is an observational study of consecutive postmortem examinations in which femur lengths and gestational age at delivery were collected, along with associated congenital anomalies and extent of fetal maceration. Between 2005 and 2012, 1530 consecutive postmortem examinations were performed and the information recorded. Fragmented fetuses (417), live-born fetuses that survived for more than 24 hours (134), fetuses with any signs of maceration (419), fetuses with known anomalies (98), and records with missing data (249) were excluded. The analyses focused on the remaining 265 nonmacerated stillborn fetuses and infants that survived for less than 24 hours after birth. The relationship between gestational age at delivery and femur length was computed, and a quadratic equation fit the data well between 12 and 40 weeks' gestation (R  =  0.944). Gestational age-specific reference ranges for radiographic femur measurements in stillbirths are equivalent to those for ultrasound-determined measurements in ongoing pregnancies. These reference data may be useful in identifying growth abnormalities in nonmacerated stillborn fetuses.

Systematic review of methodology used in ultrasound studies aimed at creating charts of fetal size

BACKGROUND

Reliable ultrasound charts are necessary for the prenatal assessment of fetal size, yet there is a wide variation of methodologies for the creation of such charts.

OBJECTIVE

To evaluate the methodological quality of studies of fetal biometry using a set of predefined quality criteria of study design, statistical analysis and reporting methods.

SEARCH STRATEGY

Electronic searches in MEDLINE, EMBASE and CINAHL, and references of retrieved articles.

SELECTION CRITERIA

Observational studies whose primary aim was to create ultrasound size charts for bi-parietal diameter, head circumference, abdominal circumference and femur length in fetuses from singleton pregnancies.

DATA COLLECTION AND ANALYSIS

Studies were scored against a predefined set of independently agreed methodological criteria and an overall quality score was given to each study. Multiple regression analysis between quality scores and study characteristics was performed.

MAIN RESULTS

Eighty-three studies met the inclusion criteria. The highest potential for bias was noted in the following fields: 'Inclusion/exclusion criteria', as none of the studies defined a rigorous set of antenatal or fetal conditions which should be excluded from analysis; 'Ultrasound quality control measures', as no study demonstrated a comprehensive quality assurance strategy; and 'Sample size calculation', which was apparent in six studies only. On multiple regression analysis, there was a positive correlation between quality scores and year of publication: quality has improved with time, yet considerable heterogeneity in study methodology is still observed today.

CONCLUSIONS

There is considerable methodological heterogeneity in studies of fetal biometry. Standardisation of methodologies is necessary in order to make correct interpretations and comparisons between different charts. A checklist of recommended methodologies is proposed.

Normal ranges for fetal femur and humerus diaphysis length during the second trimester in an Iranian population

OBJECTIVES

Shortening of the fetal long bones is a sonographic soft marker for screening of Down syndrome in the second trimester that can be influenced by ethnicity. The purpose of this study was to provide normal reference ranges for femur and humerus diaphysis length during the second trimester of pregnancy in an Iranian population.

METHODS

This cross-sectional study was performed on 3011 singleton fetuses at 15 to 28 weeks' menstrual age. The relationship between menstrual age and both femur and humerus diaphysis length was determined, and percentile values for each menstrual week were provided.

RESULTS

The median femur diaphysis length ranged from 18.05 mm at 15 menstrual weeks to 52.20 mm at 28 menstrual weeks, and the mean humerus diaphysis length ranged from 17.65 mm at 15 menstrual weeks to 48.10 mm at 28 menstrual weeks. There was a linear relationship between menstrual age and both femur diaphysis length (R² = 0.957) and humerus diaphysis length (R² = 0.941).

CONCLUSIONS

We have provided normal reference ranges for femur and humerus diaphysis length during the second trimester of pregnancy in an Iranian population.

Reference charts and equations of Korean fetal biometry

OBJECTIVE

To construct new reference charts and equations for fetal biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur diaphysis length (FDL) from Korean fetuses at 12-40 weeks.

METHOD

Prospective cross-sectional data obtained in one center for 5 years from a population of pregnant women undergoing ultrasound examination between the 12th and 40th week of gestation. Exclusion criteria comprised all maternal and fetal conditions possibly affecting fetal biometry. No fetuses were excluded on the basis of abnormal biometry. For each measurement, regression models were fitted to estimate both the mean and the standard deviation at each menstrual age.

RESULTS

Biometric measurements were obtained for 10 455 fetuses. New charts and reference equations are reported for BPD, HC, AC and FDL. Reference equations are cubic models.

CONCLUSION

We present new Korean reference charts and equations for fetal biometry. They can be easily used in obstetric ultrasound studies for the Korean population.

Fetal growth in Peru: comparisons with international fetal size charts and implications for fetal growth assessment

OBJECTIVES

To compare fetal biometry measurements obtained in a Peruvian population with reference fetal size charts obtained in Peruvian and non-Peruvian populations.

METHODS

Fetal biometry measurements collected prospectively in 195 uncomplicated pregnancies were included in the presented analysis. At 20, 24, 28, 32, 36 and 38 weeks' gestation, fetal head circumference, abdominal circumference and femur diaphysis length were measured. Fetal biometry measurements were compared with fetal size charts obtained from another Peruvian and two non-Peruvian populations from North America and Europe.

RESULTS

When compared with ultrasound-based reference fetal size charts obtained from North American and European populations, fetuses from the studied population appeared to grow more slowly with advancing gestational age. This trend was not observed when a Peruvian population, similar to the one studied here, was used as a reference.

CONCLUSIONS

The results suggest that fetal growth in this Peruvian population may not be adequately assessed by using reference charts obtained from other populations and have implications for the use of growth standards in antenatal management.