Risk factors of retained placenta in Siriraj Hospital.
OBJECTIVE
To identify risk factors associated with retained placenta after vaginal delivery.


METHODS
Case-control study.


METHODS
Medical records of 234 pregnant women whose gestational age > or =28 weeks were reviewed. Cases comprised of 78 women with retained placenta after vaginal delivery and controls comprised of 156 women with spontaneous placental delivery. Associated risk factors were examined Chi-square test and logistic regression analysis were used for analysis of data.


RESULTS
Cases were significantly older than controls (29.3 +/- 6.4 vs. 27.0 +/- 6.4 years respectively, p = 0.01). Cases were likely more significant than controls to have a previous history of uterine curettage (20.5% vs. 6.4% respectively, p = 0.001) and premature rupture of membranes (35.9% vs. 22.4% respectively, p = 0.029). Between the two groups, there were no differences in gestational age, parity, previous abortion, induction of labor, oxytocin, and pethidine usage. Logistic regression analysis showed that independent risk factors for retained placenta were age (adjusted OR 1.06, 95% CI 1.01-1.11), previous uterine curettage (adjusted OR 4.2, 95% CI 1.7-9.9), and PROM (adjusted OR 2.2, 95% CI 1.2-4.1).


CONCLUSIONS
Maternal age, previous uterine curettage, and PROM were independently associated with increased risk of retained placenta. The condition should be aware of among pregnant women with such risk factors.
Panpaprai
Pacharee
P
Department of Obstetrics and Gynecology, Faculty of Medicine, Siriraj Hospital, Bangkok 10700, Thailand.
Boriboonhirunsarn
Dittakarn
D
D016022:Case-Control Studies; D016009:Chi-Square Distribution; D004107:Dilatation and Curettage / Q000009:adverse effects; D005260:Female; D005322:Premature Rupture of Fetal Membranes; D006801:Humans; D016015:Logistic Models; D008423:Maternal Age; D018457:Placenta, Retained / Q000453:epidemiology*; D006473:Postpartum Hemorrhage / Q000209:etiology*; D049590:Postpartum Period; D011247:Pregnancy; D012307:Risk Factors; D013785:Thailand / Q000453:epidemiology