Prediction of low birthweight and small for gestational age from symphysis-fundal height mainly in developing countries: a meta-analysis.

BACKGROUND: A highly sensitive and simple screening procedure is required for early detection of low birthweight and small for gestational age, especially in developing countries.
METHODS: A meta-analysis was performed to evaluate use of symphysis-fundal height for prediction of low birthweight and small for gestational age. PubMed (MEDLINE) and other databases were used with no limitation on the date of publication (January 2012). The inclusion criteria were moderate-to-high-quality studies, that is, Quality Assessment Tool for Diagnostic Accuracy Studies (QUADAS) score ≥8, published in English, which provided true and false, positive and negative results for prediction. 2×2 tables were constructed and diagnostic meta-analysis was performed.
RESULTS: 46 studies, which were conducted mostly in hospitals, evaluated the prediction of low birthweight (n=12) or small for gestational age (n=34). Only specificity to predict small for gestational age (0.87) was relatively high. Sensitivity to predict low birthweight (0.72) or small for gestational age (0.58) and specificity to predict low birthweight (0.73) were not sufficiently high. Regardless of predicting low birthweight or small for gestational age, the diagnostic accuracy was moderate (0.7≤ area under the curve≤0.9) and informational value was small (but sometimes important; positive and negative likelihood ratios of 2-5 and 0.5-0.2, respectively).
CONCLUSIONS: The present meta-analysis suggested that symphysis-fundal height is unsuitable for primary screening of low birthweight or small for gestational age. The results may be overly optimistic due to the inclusion of hospital-based versus community-based studies.