Determination of Accuracy of Fetal Weight Using Ultrasound and Clinical Fetal Weight Estimations in Calabar South, South Nigeria

Accuracy of Dare's formula in estimating fetal birth weight in pregnant women

OBJECTIVE

To evaluate the accuracy of Dare's formula in estimating fetal birth weight in pregnant women.

METHODS

A prospective study was conducted at a tertiary care hospital in New Delhi after institutional ethical committee clearance. In all, 175 pregnant women with singleton pregnancies of 37 weeks or more were included. The aim was to assess fetal birth weight by Dare's formula and ultrasonography. This estimated fetal weight (EFW) was compared with actual birth weight (ABW) of newborn.

RESULTS

Estimated fetal birth weight by Dare's formula was within 10% of ABW in 77 (44.00%) cases. Meanwhile in the majority (98; 56.00%), EFW by Dare's formula was not within 10% of ABW. The proportion of EFW by ultrasonography within 10% and not within 10% of ABW were comparable (50.29% [88] and 49.71% [87], respectively).

CONCLUSION

Dare's formula can be used by medical personnel as a clinical method in routine prenatal care to estimate fetal weight, for better management of women in labor to decrease the maternal and neonatal mortality and morbidity.

Investigating the accuracy of Johnson's rule in estimating fetal weight

BACKGROUND

Birth weight has a significant impact on perinatal mortality. Therefore, the estimation of fetal weight greatly influences the policies necessary for care during and after delivery. We aimed to investigate Johnson's rule in estimating fetal weight.

MATERIALS AND METHOD

This study was a single-group longitudinal study that was conducted in 6 months from October 2021 to April 2022 on 150 pregnant women in Isfahan-Iran. The sampling method was accessible. Inclusion criteria include being term, singleton, without abnormality, intact membranes, cephalic presentation, and exclusion criteria include diagnosed polyhydramnios or oligohydramnios and mother's abdominal or pelvic known masses. After completing the informed consent, fetal weight was estimated by Johnson's rule and was compared with the birth weight. Descriptive and analytical statistics (mean-standard deviation (SD), number-percentage, t-paired, and Spearman's correlation coefficient) were used to achieve the objectives of the study. The receiver operating characteristic (ROC) curve was also used to determine the sensitivity, specificity, and positive and negative predictive value of Johnson's law.

RESULT

The mean (SD) birth weight was 3032.88 ± 481.11 g and the mean (SD) estimated fetal weight (EFW) by the clinical method was 3152.15 ± 391.95 g. There was a significant difference between the averages (P < 0.001). The percentage error of EFW showed a significant negative correlation (r = -0.286; P < 0.05) with gestational age (GA) and a significant positive correlation (r = 0.263; P < 0.05) with the fetal head station. The sensitivity and specificity of EFW with Johnson's rule, in normal fetal birth weight, were higher than in low birth weight fetal. The accuracy of EFW with ± 10% of the actual weight was higher in average for gestational age (AGA) (84.3%) and high-for-gestational-age (LGA) (70%) than in low-for-gestational-age (SGA) (4%). The EFW mean percentage error in SGA was higher than in the other two weight groups. This method, especially for AGA and LGA fetuses, can be a suitable alternative to other weight estimation methods.

CONCLUSION

Clinical estimation of weight via Johnson's rule due to availability and no cost can be a suitable method for managing childbirth based on fetal weight.

Accuracy of Fetal Weight Estimation by Ultrasonographic Evaluation in a Northeastern Region of India

Methods

The cross-sectional study included 100 pregnant women aged 20–45 years from the Kamrup district admitted to Guwahati Medical College and Hospital, Guwahati, Assam. The data were analyzed using Microsoft Excel and SPSS version 16. The EFW at term was calculated using Shepard's formula and Hadlock's formula. Differences in means are compared using the one-way ANOVA or Kruskal–Wallis test and paired t-test. The accuracy of the two procedures was evaluated using mean absolute error (MAE) and mean absolute percentage error (MAPE). A p value<0.05 was considered significant.

Results

The present study included 100 pregnant women aged 21–38 years with term or postterm pregnancies subjected to ultrasonographic evaluation within 72 hours of delivery. The mean (±s.d.) EFW by Shepard's formula was 2716.05 (±332.38) g and Hadlock's formula was 2740.44 (±353.23) g, respectively. For Hadlock's formula, MAE ± s.d. was found to be higher (overall 84.59 ± 76.54) specifically in the weight category less than 2500 (106.42 ± 88.11) as compared to Shepard's (overall MAE ± s.d = 79.86 ± 64.78, and among ABW < 2500 g, MAE ± s.d = 65.04 ± 61.02). The overall MAPE of Hadlock's formula was 3.14% and that for Shepard's formula was 2.91%, and the difference was not statistically significant. Both Shepard's formula and Hadlock's formula had a sensitivity of 92.85% in detecting IUGR, but Hadlock's method had higher specificity (66%), higher PPV (86.67%), and higher NPV (80%).

Conclusion

The ultrasonographic evaluation of fetal weight helps predict fetal birth weight precisely and can influence obstetric management decisions concerning timing and route of delivery, thus reducing perinatal morbidity and mortality.

Reliability of a clinical method in estimating foetal weight and predicting route of delivery in term parturient monitored at a voluntary agency hospital in Southwest Nigeria

BACKGROUND

The antepartum estimation of foetal weight is a major determinant of the route of delivery and this has become vital in modern day obstetrics. The limitations to the use of obstetric ultrasonography, considered as the gold standard in estimating foetal weight, make clinical estimation methods attractive alternatives, especially in resource- constrained settings where many un-booked women may report for delivery.

AIM

To determine the reliability of intrapartum clinical foetal weight estimation in predicting the actual birth weight (ABW) and route of delivery among term parturient.

SETTING

The study was conducted at the Sacred Heart Hospital, Lantoro, a voluntary mission agency hospital in Southwest Nigeria.

METHODS

This cross-sectional study was conducted among 291 term parturient recruited by systematic random sampling between June and September 2017. The clinical estimation of foetal weight was carried out using Johnson's formula.

RESULTS

The accuracy of Johnson's formula to predict the ABW was 59.5%; while for the mode of delivery, it was 130 (75.1%) for spontaneous vaginal delivery (SVD) and 43 (24.9%) for caesarean section (CS). The sensitivity of the accuracy of Johnson's formula to predict the mode of delivery was 75.1%, with a specificity of 35.6%, a positive predictive value (PPV) of 63.1%, and a negative predictive value (NPV) of 49.4%.

CONCLUSION

The intrapartum clinical foetal weight estimation at term determined by Johnson's formula was reliably predictive of ABW and SVD, but it was unreliable in predicting the need for a CS.

Prospective verification of sonographic fetal weight estimators among term parturients in Uganda

BACKGROUND

Accuracy of fetal weight estimation by ultrasound is essential in making decisions on the time and mode of delivery. There are many proposed formulas for fetal weight estimation such as Hadlock 1, Hadlock 2, Hadlock 3, Hadlock 4 and Shepard. What best applies to the Ugandan population is not known since no verification of any of the formulas has been done before. The primary aim of this study was to determine the accuracy of sonographic estimation of fetal weight using five most commonly used formulas, and analyze formula variations for different weight ranges.

METHODS

This was a hospital based prospective cohort study at Mulago National Referral Hospital, Kampala, Uganda. A total of 356 pregnant women who consented and were within 3 days of birth were enrolled. Prenatal ultrasound fetal weight determined by measuring the biparietal diameter, head circumference, abdominal circumference, femoral length, and then was compared with actual birth weight.

RESULTS

The overall accuracy of Hadlock 1, Hadlock 2, Hadlock 3, Hadlock 4 and Shepard formula were 66.9, 73.3, 77.3, 78.4 and 69.7% respectively. All Hadlocks showed significant mean difference between weight estimates and actual birth weight (p < 0.01) whereas Shepard formula did not [p - 0.2], when no stratification of fetal weights was done. However, all Hadlocks showed a none significant (p-values > 0.05) mean difference between weight estimates and actual birth weight when the actual birth weight was ≥4000.0 g. Shepard weight estimates showed a none significant mean difference when actual birth weight was < 4000 g. Bland-Altman graphs also showed a better agreement of weight estimated by Shepard formula and actual birth weights.

CONCLUSION

All the five formulas were accurate at estimating actual birth weights within 10% accuracy. However, this accuracy varied with the fetal birth weight. Shepard was more accurate in estimating actual birth weights < 4000 g whereas all Hadlocks were more accurate when the actual birthweight was ≥4000 g.

Evaluating the Effect of Utrogestan on Idiopathic Intrauterine Growth Retardation

Background:

Intrauterine growth factor (IUGR) is one of the most important causes of neonatal mortality. The aim of this study was to evaluate the therapeutic effect of utrogestan on the treatment of IUGR and its complications.

Materials and Methods:

In this clinical trial, 66 pregnant women with idiopathic IUGR embryos were enrolled. Patients in the intervention group, in addition to receiving routine treatment of control group (high-protein diet, resting), took utrogestan capsules (100 mg) twice daily. The primary and secondary outcomes of the disease were recorded in a checklist. Data were analyzed using SPSS 18 using an independent t-test, Chi-square test, and Fisher's exact test.

Results:

In the intervention group, mean neonatal weight (P = 0.003), mean neonatal Apgar score (P = 0.001), and mean gestational age at birth (P = 0.001) were significantly higher than those in the control group. There was no neonatal death in the intervention group, whereas in the control group, four cases of neonatal death were observed (P = 0.03). In the majority of subjects in the intervention group, resistance index, and pulsatility index of the umbilical artery decreased (P = 0.002). The difference in abdominal circumference and gestational age in the intervention group decreased (P = 0.01). In the intervention group, the diastolic flow of the umbilical artery increased (P = 0.002).

Conclusion:

Utrogestan was effective as an inexpensive and effective way to treat IUGR and improve pregnancy outcomes.

Accuracy of the product of symphysio-fundal height and abdominal girth in prediction of birth weight among term pregnant women at Keffi, Nigeria

BACKGROUND

A reliable prediction of foetal birth weight aids in decision regarding time and mode of delivery.

AIM

This study aimed to determine the accuracy of the product of symphysio-fundal height and abdominal girth in predicting birth weight among pregnant women in Keffi, Nigeria.

SETTING

The study involved pregnant women presenting for delivery at the Federal Medical Centre, Keffi, Nigeria from July to October 2017.

METHODS

One hundred and fifty-three pregnant women at term with singleton foetuses were recruited by systematic random sampling. An interviewer-administered questionnaire was used to obtain their socio-demographic data, past medical and obstetric history. Symphysio-fundal height and abdominal girth measurements were used to calculate the estimated foetal weight. This was compared with the actual birth weight. Absolute percentage error was used to determine the overall predictive error of Dare's formula. Data were analysed using SPSS version 20.0. Statistical significance was set at p 0.05 and 95% confidence level.

RESULTS

The mean age of the participants was 29.65 ± 5.15 years. The mean gestational age was 39.5 ± 1.2 weeks. There was a significant correlation (r = 0.52, p 0.001) between the estimated foetal weight and the actual birth weight. Ninety (66.2%) of the babies within normal weight and six (85.7%) of macrosomic babies were correctly predicted. None of the low birth weight babies was correctly predicted by the formula.

CONCLUSION

Dare's formula accurately predicted normal weight and macrosomic babies, but less accurately predicted low birth weight babies.

Correlation of Ultrasonographic Estimation of Fetal Weight with Actual Birth Weight as Seen in a Private Specialist Hospital in South East Nigeria

Background

Ultrasound estimation of fetal weight at term provides vital information for the skilled birth attendants to make decisions on the possible best route of delivery of the fetus. This is more pertinent in a setting where women book late for antenatal care.

Aim and Objectives

The study evaluated the accuracy of estimation of fetal weight with ultrasound machine at term.

Methods

This was a cross sectional study conducted at a private specialist hospital in Nigeria. A coded questionnaire was used to retrieve relevant information which included the last menstrual period, gestational age, parity, and birth weight. Other information obtained includes Ultrasound-delivery interval, maternal weight, and route of delivery. The ultrasound was used to estimate the fetal weight. The actual birth weight was determined using a digital baby weighing scale. The data were inputted into Microsoft excel and analyzed using STATA version 14. Statistical significance was considered at p-values less than 0.05. Measures of accuracy evaluated in the statistical analysis included mean error, mean absolute error, mean percentage error, and mean absolute percentage error. Pearson correlation was done between the estimated ultrasound fetal weight and the actual birth weight. The proportion of estimates within ±10% of actual birth weight was also determined.

Result

A total of 170 pregnant women participated in the study. The mean maternal age was 30.77 years ± 5.54. The mean birth weight was 3.47 kg ± 0.47, while the mean estimated ultrasound weight was 3.43 kg ± 0.8. There was positive correlation between the ultrasound estimated weight and the actual birth weight. The mean ultrasound scan to delivery interval was 0.8 days (with range of 0–2 days). The study recorded a mean error of estimation of 41.17 grams and mean absolute error of 258.22 grams. The mean percentage error was 0.65%, while the mean absolute error of estimation was 7.56%. About 72.54% of the estimated weights were within 10% of the actual birth weight.

Conclusion

The ultrasound estimated fetal weight correlated with the actual birth weight. Ultrasound estimation of fetal weight should be done when indicated to aid the clinician in making decisions concerning routes of delivery.

Five-dimensional long bones biometry for estimation of femur length and fetal weight at term compared to two-dimensional ultrasound: a pilot study

BACKGROUND/OBJECTIVE

This study aimed to evaluate accuracy of five-dimensional long bones (5D LB) compared to two-dimensional ultrasound (2DUS) biometry to predict fetal weight among normal term women.

METHODS

Fifty six normal term women were recruited at Ain Shams Maternity Hospital, Egypt from 14 May to 30 November 2015. Fetal weight was estimated by Hadlock's IV formula using 2DUS and 5D LB. Estimated fetal weights (EFW) by 2DUS and 5D LB were compared with actual birth weights (ABW).

RESULTS

Mean femur length (FL) was 7.07 ± 0.73 cm and 6.74 ± 0.67 cm by 2DUS and 5D LB (p = .02). EFW was 3309.86 ± 463.06 g by 2DUS and 3205.46 ± 447.85 g by 5D LB (p = .25). No statistical difference was observed between ABW and EFW by 2DUS (p = .7) or 5D LB (p = .45). Positive correlation was found between EFW by 2DUS, 5D LB, and ABW (r = 0.67 and 0.7; p < .001). There was strong agreement between FL measured by 2DUS and 5D LB (ICC = 0.78), and perfect agreement between EFW by 2DUS and EFW by 5D LB (ICC = 0.918). 2DUS and 5D LB showed mean absolute percentage error for EFW of 10 ± 7% and 8 ± 7% compared to ABW (p = .15).

CONCLUSIONS

2DUS and 5D LB had same accuracy for fetal weight estimation at normal term pregnancy.