Birth weight, prematurity and accuracy of gestational age.
Int J Gynaecol Obstet
; 56(3): 251-6, 1997 Mar.
Article
em En
| MEDLINE
| ID: mdl-9127157
ABSTRACT
OBJECTIVE:
To investigate commonly used birth weight categories in relation to gestational age assignment by menstrual (LMP) or ultrasound dates.METHODS:
A total of 34,249 cases were retrieved from the East Midlands Obstetric Database. Of these, 2281 (6.7%) delivered preterm (< 37 weeks) by ultrasound dating. The percentage of preterm and post-term cases was calculated for birth weight categories from < 1500 g to > 4499 g at 500 g intervals. The incidence of preterm delivery was estimated for birth weights from < 1500 g to 3400 g.RESULTS:
For the 'low birth weight' cut-off of 2500 g, only 64% were actually preterm as assessed by ultrasound, as opposed to 59% as judged by menstrual dates. Nearly 95% of infants weighing over 3000 g are full-term. For birth weights under 2900 g, there is a trend for LMP-derived gestational age to underestimate preterm delivery, by up to 35.5%. By ultrasound dating, 90% of infants under 1800 g are preterm, rising to 98.2% for those under 1500 g.CONCLUSIONS:
As nearly 40% of 'low birth weight' infants are born at term, the old classification of 'low birth weight' should be replaced by gestational age-specific percentile categories. Menstrual dates systematically underestimate the prevalence of preterm delivery. Previous estimates of preterm delivery rates based on LMP data have under-stated their true incidence.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Peso ao Nascer
/
Ultrassonografia Pré-Natal
/
Idade Gestacional
/
Trabalho de Parto Prematuro
Tipo de estudo:
Diagnostic_studies
/
Risk_factors_studies
Limite:
Adult
/
Female
/
Humans
/
Newborn
/
Pregnancy
Idioma:
En
Ano de publicação:
1997
Tipo de documento:
Article