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PubMed · 2677864

Cephalic index: a gestational age-dependent biometric parameter.

D L Gray·G S Songster·C A Parvin·J P Crane
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Abstract

Cephalic index was proposed originally as a means of recognizing altered head shape and confirming the validity of biparietal diameter (BPD) measurements. Two previous studies found cephalic index to be gestational age-independent. We tested this relationship by regression analysis in 777 well-dated pregnancies, evenly distributed between 14-40 weeks' gestation. Significant variation in cephalic index was found with advancing gestational age, with the highest and lowest values observed at 14 and 28 weeks, respectively. Based upon application in a separate test population of 1361 normal fetuses, a threshold of +/- 1 SD maximized identification of misleading BPDs due to altered head shape.

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CephalometryFemaleFetal MonitoringGestational AgeHumansPregnancyReference ValuesUltrasonographyJournal ArticleResearch Support, U.S. Gov't, P.H.S.

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D L Gray, G S Songster, C A Parvin, J P Crane. 1989. Cephalic index: a gestational age-dependent biometric parameter.. https://pubmed.ncbi.nlm.nih.gov/2677864/

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