J. Kristensen et al., IMPLICATIONS OF IDIOPATHIC PRETERM DELIVERY FOR PREVIOUS AND SUBSEQUENT PREGNANCIES, Obstetrics and gynecology, 86(5), 1995, pp. 800-804
Objective: To describe the relationship between pregnancy complication
s and fetal outcome in first and second pregnancies, focusing on idiop
athic and indicated preterm birth of singleton infants in either pregn
ancy. Methods: Included in the study were 13,967 women in Denmark who
gave birth to their first singleton infant in 1982 and a second infant
in 1982-1987. Information on pregnancy and birth was obtained by link
ing the National Medical Birth Register and the National Register of H
ospital Discharges, based on personal identification numbers. Results:
The risk of a preterm second birth in women with idiopathic and indic
ated preterm first birth did not differ significantly (15.2 and 12.8%,
respectively). However, women with idiopathic preterm birth in the fi
rst pregnancy tended to repeat idiopathic preterm birth twice as often
as women with indicated preterm birth repeated indicated preterm birt
h (11.3 versus 6.4%). Adjustment by logistic regression analysis for o
ther risk factors for preterm birth did not influence the relative ris
k (6.0 before 32 weeks and 4.8 for 32-36 weeks) of a second preterm bi
rth after a first preterm birth. Women with idiopathic preterm deliver
y in their first and second pregnancies gave birth to infants with low
er birth weight than in previous or subsequent pregnancies. Emergency
cesarean delivery in a first term pregnancy was a risk factor for subs
equent idiopathic preterm birth. Conclusion: Idiopathic preterm birth
is associated with emergency cesarean delivery at term in previous pre
gnancies and infants with lower birth weight in previous and subsequen
t pregnancies.