Does induced abortion increase the risk of preterm birth? Results from a case-control study.
OBJECTIVE
We analyzed the association between previous induced abortions and risk of preterm birth.


METHODS
This was a case-control study. Cases were 502 women who delivered preterm babies at the Clinica Luigi Mangiagalli and the Obstetric and Gynecology Clinic of the University of Verona. Controls were 1,966 women who gave birth at term (> or = 37 weeks of gestation) to healthy infants of normal weight.


RESULTS
The odds ratio for all preterm births was 0.7 (95% CI 0.5-1.1) for women reporting 1 induced abortion and 1.6 (95% CI 0.7-3.5) for those reporting 2 or more induced abortions (chi(2) trend p = 0.81). Previous induced abortions did not increase the risk of preterm birth, both in small and normal for gestational age preterm infants. No difference emerged in risk factors for infants born at <32 and 32-36 gestational weeks.


CONCLUSIONS
This study does not support the suggestion that induced abortions, as performed in Italy during the study period, increase the risk of preterm delivery in subsequent pregnancies.
Parazzini
Fabio
F
Istituto di Ricerche Farmacologiche Mario Negri, Università di Milano, IT-20122 Milan, Italy.
Ricci
Elena
E
Chiaffarino
Francesca
F
Cipriani
Sonia
S
Tozzi
Luca
L
Fedele
Luigi
L
D000028:Abortion, Induced / Q000009:adverse effects / Q000706:statistics & numerical data*; D000328:Adult; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007558:Italy / Q000453:epidemiology; D011247:Pregnancy; D047928:Premature Birth / Q000453:epidemiology* / Q000209:etiology; D012044:Regression Analysis; D012307:Risk Factors