Foetal weight prediction models at a given gestational age in the absence of ultrasound facilities: application in Indonesia

Abstract

BackgroundBirth weight is one of the most important indicators of neonatal survival. A reliable estimate of foetal weight at different stages of pregnancy would facilitate intervention plans for medical practitioners to prevent the risk of low birth weight delivery. This study has developed reliable models to more accurately predict estimated foetal weight at a given gestation age in the absence of ultrasound facilities.MethodsA primary health care centre was involved in collecting retrospective non-identified Indonesian data. The best subset model selection criteria, coefficient of determination, standard deviation, variance inflation factor, Mallows Cp, and diagnostic tests of residuals were deployed to select the most significant independent variables. Simple and multivariate linear regressions were used to develop the proposed models. The efficacy of models for predicting foetal weight at a given gestational age was assessed using multi-prediction accuracy measures.ResultsFour weight prediction models based on fundal height and its combinations with gestational age (between 32 and 41 weeks) and ultrasonic estimates of foetal head circumference and foetal abdominal circumference have been developed. Multiple comparison criteria show that the proposed models were more accurate than the existing models (mean prediction errors between − 0.2 and 2.4 g and median absolute percentage errors between 4.1 and 4.2%) in predicting foetal weight at a given gestational age (between 35 and 41 weeks).ConclusionsThis research has developed models to more accurately predict estimated foetal weight at a given gestational age in the absence of ultrasound machines and trained ultra-sonographers. The efficacy of the models was assessed using retrospective data. The results show that the proposed models produced less error than the existing clinical and ultrasonic models. This research has resulted in the development of models where ultrasound facilities do not exist, to predict the estimated foetal weight at varying gestational age. This would promote the development of foetal inter growth charts, which are currently unavailable in Indonesian primary health care systems. Consistent monitoring of foetal growth would alleviate the risk of having inter growth abnormalities, such as low birth weight that is the most leading factor of neonatal mortality.Electronic supplementary materialThe online version of this article (10.1186/s12884-018-2047-z) contains supplementary material, which is available to authorized users.

The development of an alternative growth chart for estimated fetal weight in the absence of ultrasound: Application in Indonesia

“…was developed based on FH measurement recorded between 35 and 41 weeks (before delivery) and actual birth weight. The model in Eq (1) was the improvement of the clinical model published in Anggraini, et al [6], which was developed using recorded estimated weight based on the existing Johnson-Toshach formula [20]. Several accuracy measures used in this study, such as mean prediction error (ME), mean percentage prediction error (MPE), mean absolute percentage prediction error (MAPE), and median absolute percentage prediction error (MEDAPE).…”

“…Several accuracy measures used in this study, such as mean prediction error (ME), mean percentage prediction error (MPE), mean absolute percentage prediction error (MAPE), and median absolute percentage prediction error (MEDAPE). The number of estimates within 10% and 20% of ABWs (%) is also used to measure the prediction accuracy [6]. In this study, however, a two-sample T-test and a two-sample F-test were added to investigate if there is a significant difference in mean and variance of prediction errors between the existing and proposed models.…”

“…This error is smaller than in the previous research (-10.7%) on babies born precisely 14 days after the last scan (n = 196). In the previous publication [6], it has been shown that a weight prediction model based on FH only produced fewer errors compared with the existing clinical and ultrasound models. Therefore, the proposed model, as the improvement of the previously published model [6], can be a potential weight prediction model to be used in the development of an alternative fetal growth chart for EFW.…”

“…In the previous publication [6], it has been shown that a weight prediction model based on FH only produced fewer errors compared with the existing clinical and ultrasound models. Therefore, the proposed model, as the improvement of the previously published model [6], can be a potential weight prediction model to be used in the development of an alternative fetal growth chart for EFW. This is particularly significant for those who are living in rural areas where ultrasound is not always accessible.…”

“…Birth weight is closely associated with fetal growth [5]. The measurement of fetal weight during pregnancy is used to estimate the expected (normal) birth weight [6]. Since fetal weight cannot be directly measured, its reliable estimation at different stages of pregnancy has become one of the important issues in obstetrics and gynecology, and one of the key elements in developing a fetal growth chart for the estimated fetal weight (EFW).…”