Risk factors associated with preterm (<37+0 weeks) and early preterm birth (<32+0 weeks): univariate and multivariate analysis of 106 345 singleton births from the 1994 statewide perinatal survey of Bavaria.
OBJECTIVE
The study was conducted to identify medical, obstetrical and social risk factors associated with early preterm births (<32+0 gestational weeks).


METHODS
The Statewide Perinatal Survey of Bavaria is a collection of perinatal data from all Bavarian maternity units using a uniform numbered questionnaire. Data on 106345 singleton births from the 1994 Survey were analysed using univariate and multivariate logistic regression analysis.


RESULTS
In the multivariate analysis, early preterm birth was associated with premature rupture of the membranes (odds ratio (OR) 1.6, 95% confidence interval (CI) 1.37-1.86), treatment for infertility (OR 1.7, 95% CI 1.19-2.34), previous induced abortion (OR 1.8, 95% CI 1.57-2.13), maternal age >35 years (OR 1.8, 95% CI 1.47-2.16), premature cervical dilatation (OR 2.3, 95% CI 1.86-2.94), a history of stillbirth (OR 3.2, 95% CI 2.13-4.83), a history of preterm birth (OR 3.3, 95% CI 2.45-4.48), maternal age <18 years (OR 3.4, 95% CI 2.03-5.61), malpresentation (OR 3.9, 95% CI 3.10-4.93), preeclampsia (OR 4.0, 95% CI 3.20-4.94), uterine bleeding (OR 5.0, 95% CI 4.08-6.02), preterm labour (OR 7.0, 95% CI 5.94-8.22), and chorioamnionitis (OR 22.3, 95% CI 17.40-28.66).


CONCLUSIONS
These data identify a subgroup of women at an increased risk for early preterm birth and may benefit from an intensified prenatal care. Risk factors related to the obstetrical history, genital infections, preeclampsia and maternal age are the most relevant for early preterm birth.
Martius
J A
JA
Department of Obstetrics and Gynecology, University of Würzburg, Germany.
Steck
T
T
Oehler
M K
MK
Wulf
K H
KH
D000028:Abortion, Induced / Q000009:adverse effects; D000022:Abortion, Spontaneous / Q000150:complications; D002821:Chorioamnionitis / Q000150:complications; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000150:complications; D005858:Germany; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007246:Infertility / Q000628:therapy; D016015:Logistic Models; D008423:Maternal Age; D007752:Obstetric Labor, Premature / Q000150:complications; D011225:Pre-Eclampsia / Q000150:complications; D011247:Pregnancy; D018566:Pregnancy, High-Risk; D012307:Risk Factors; D011795:Surveys and Questionnaires; D002581:Uterine Cervical Incompetence / Q000150:complications