Gestational age assessment by nurses in a developing country using the Ballard method, external criteria only.

The aim of this study was to evaluate postnatal examination of the newborn by nurses in a developing country, using a modified Ballard method, scoring for the six external criteria only (Ballard-ext). Applicability of gestational age estimates with the Ballard-ext. was assessed by calculating its agreement with gestational age derived from the last menstrual period (LMP), fundal height and the Dubowitz method. The smallest difference in gestational age and the most narrow limits of agreement were found between the Ballard-ext. and the Dubowitz method. No reliable gestational age could be obtained from LMP or fundal height. At low gestational ages, Ballard-ext. tended to give lower gestational ages compared with the Dubowitz method. At an average gestational age of more than 251 days, Ballard-ext. gave higher values compared with Dubowitz. Both Ballard-ext. and the Dubowitz method identified 48% of low birthweight babies as growth-retarded (gestational age > or = 37 weeks). No significant difference in gestational age assessment of newborns between nurses was observed. The Ballard method, scoring for external criteria alone, compared favourably with the Dubowitz method. The test is simple to perform and can be reliably used routinely by nurses.