[Algorithm for an etiological classification of prematurity].
The etiology of preterm birth is difficult to classify. It is usually divided into three clinical types according to its clinical presentation: medically indicated; caused by ruptured membranes; and spontaneous or idiopathic. However, this classification is controversial, imprecise and can result in multiple interpretations when applied.


OBJECTIVE
To design an etiologically based classification of preterm birth, and to design a system to easily assign each case during the perinatal period.


METHODS
Review of literature, qualitative analysis using consensus methods through nominal group technique, and quantitative analysis of a pilot study using a first version of the algorithm.


RESULTS
A classification is made to establish a general division between the "primary cause" and "associated causes" of preterm birth, that allows remote causes or risk factors to be included. The primary cause includes seven categories: inflammatory (ruptured membranes and related); vascular (intrauterine growth restriction and related); maternal-local; maternal-systemic; fetal pathology; fetal distress; idiopathic. The medically indicated preterm birth is defined as a previous or independent category and so is compatible with the other, previously mentioned causes . An algorithm was designed to make it easier to classify the primary cause of preterm birth using a flowchart.


CONCLUSIONS
A pragmatic classification of preterm birth is proposed that may help to achieve better precision and agreement between clinicians.
Alvarez Serra
J
J
Hospital Universitari Sant Joan de Déu, Esplugues de Llobregat, Barcelona, España.
Balaguer
A
A
Iriondo
M
M
Ancel
A Martín
AM
Roig
M D Gómez
MD
Iglesias
I
I
Krauel
X
X
D000465:Algorithms; D006801:Humans; D007231:Infant, Newborn; D047928:Premature Birth / Q000145:classification* / Q000209:etiology*