Retained placenta is associated with pre-eclampsia, stillbirth, giving birth to a small-for-gestational-age infant, and spontaneous preterm birth: a national register-based study
Article first published online: 7 APR 2014
© 2014 Royal College of Obstetricians and Gynaecologists
BJOG: An International Journal of Obstetrics & Gynaecology
Volume 121, Issue 12, pages 1462–1470, November 2014
How to Cite
Retained placenta is associated with pre-eclampsia, stillbirth, giving birth to a small-for-gestational-age infant, and spontaneous preterm birth: a national register-based study. BJOG 2014;121:1462–1470., , , , .
- Issue published online: 27 OCT 2014
- Article first published online: 7 APR 2014
- Manuscript Accepted: 8 FEB 2014
- Division of Obstetrics and Gynaecology
- Postpartum haemorrhage;
- preterm birth;
- retained placenta;
- small for gestational age;
To evaluate whether defective placentation disorders, i.e. pre-eclampsia, stillbirth, small for gestational age (SGA), and spontaneous preterm birth, are associated with risk of retained placenta.
Population-based cohort study.
Primiparous women in Sweden with singleton vaginal deliveries between 1997 and 2009 at 32–41 weeks of gestation (n = 386 607), without placental abruption or infants with congenital malformations.
Risks were calculated as odds ratios (ORs) by unconditional logistic regression with 95% confidence intervals (95% CIs) after adjustments for maternal, delivery, and infant characteristics.
Main outcome measure
Retained placenta, defined by the presence of both a diagnostic code (of retained placenta) and a procedure code (for the manual removal of the placenta).
The overall rate of retained placenta was 2.17%. The risk of retained placenta was increased for women with pre-eclampsia (adjusted OR, aOR, 1.37, 95% CI 1.21–1.54), stillbirth (aOR 1.71, 95% CI 1.28–2.29), SGA birth (aOR 1.47, 95% CI 1.28–1.70), and spontaneous preterm birth (32–34 weeks of gestation, aOR 2.35, 95% CI 1.97–2.81; 35–36 weeks of gestation, aOR 1.55, 95% CI 1.37–1.75). The risk was further increased for women with preterm pre-eclampsia (aOR 1.69, 95% CI 1.25–2.28) and preterm SGA birth (aOR 2.19, 95% CI 1.42–3.38). There was no association between preterm stillbirth (aOR 1.10, 95% CI 0.63–1.92) and retained placenta, but the exposed group comprised only 15 cases.
Defective placentation disorders are associated with an increased risk of retained placenta. Whether these relationships indicate a common pathophysiology remains to be investigated.