The development and evaluation of a simple method of gestational age estimation.

AIMS

The aims of this study were to develop and evaluate a shorter gestational age estimation method based on the Dubowitz scoring system (DSS) that could be taught easily to untrained health-care workers.

METHODS

Using the DSS, seven criteria were identified that explained 90% of the variance in gestational age estimation. Ventral suspension was excluded, skin texture was substituted for skin colour and ear bending was for ear firmness. The final six criteria comprise the short DSS (SDSS). The study population was 100 babies, 51 Caucasian, 34 Aboriginal. Birth weight ranged from 1351 to 5430 g. The gestational age range was 29.6-41.7 weeks. Three researchers (medical student 1 (MS1), medical student 2 (MS2) and a paediatrician) who were blind to other available gestational age estimations assessed babies within 72 h of birth using the DSS and SDSS.

RESULTS

MS1 found the 95% limits of agreement (LOA) between SDSS and DSS to be -1.1 to 1.7 weeks. In the 27 babies who had first trimester foetal ultrasound (USS), the LOA between USS and SDSS were -1.9 to 1.4 weeks and -2.3 to 1.9 weeks, respectively. Using the SDSS, the LOA for the three researchers were within +/-2 weeks.

CONCLUSION

The data presented suggest that the SDSS is approximately equivalent to the DSS in the relatively limited population studied, and within these limitations appears to be a simple alternative to the DSS. Further evaluation is needed before firm conclusions about the accuracy and clinical utility of the SDSS can be made.