[Risk factors for prematurity in France and comparisons between spontaneous prematurity and induced labor: results from The National Perinatal Survey 1995].
OBJECTIVE
To study risk factors of total preterm delivery, spontaneous preterm delivery and induced preterm delivery.


METHODS
Representative sample of births in 1995 in France, including 12869 single births.


METHODS
Preterm deliveries included all births before 37 weeks. Risk factors were analyzed with logistic regression. Factors of spontaneous preterm delivery (after spontaneous onset of labor) and factors of induced preterm delivery (after induction or cesarean section before labor) were compared with polytomous logistic regression.


RESULTS
The main risk factors of preterm delivery were history of adverse pregnancy outcome (ORa=4. 5), history of induced abortion (ORa=1.5), 35 year old or more (ORa=1.5) and inadequate antenatal care (ORa=2.1). Other factors such as age under 20 or being single were not significantly linked to preterm delivery. Risk factors differed slightly between spontaneous and induced preterm deliveries.


CONCLUSIONS
The present risk factors do not always correspond with the well-known factors. Thus the assessment of risk factors would be necessary at regular interval. The small differences between the risk factors of spontaneous preterm delivery and induced preterm delivery may be explained by difficulties in defining those two types of preterm delivery or by difficulties in distinguishing specific causes for each of them.
Foix-L'Hélias
L
L
Unité de Recherches Epidémiologiques sur la Santé des Femmes et des Enfants, INSERM, Villejuif.
Ancel
P Y
PY
Blondel
B
B
D000328:Adult; D036861:Delivery, Obstetric / Q000379:methods / Q000706:statistics & numerical data*; D005260:Female; D005307:Fertilization in Vitro / Q000009:adverse effects; D005602:France / Q000453:epidemiology; D006801:Humans; D007231:Infant, Newborn; D007751:Labor, Induced / Q000706:statistics & numerical data*; D016015:Logistic Models; D008297:Male; D007752:Obstetric Labor, Premature / Q000453:epidemiology* / Q000209:etiology*; D010298:Parity; D011159:Population Surveillance; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000453:epidemiology; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects