Risk of retained placenta in women previously delivered by caesarean section: a population-based cohort study.

Abstract

OBJECTIVE:

To evaluate whether women with a caesarean section at their first delivery have an increased risk of retained placenta at their second delivery.

DESIGN:

Population-based cohort study.

SETTING:

Sweden.

POPULATION:

All women with their first and second singleton deliveries in Sweden during the years 1994-2006 (n = 258,608). Women with caesarean section or placental abruption in their second pregnancy were not included in the study population.

METHODS:

The risk of retained placenta at second delivery was estimated for women with a first delivery by caesarean section (n = 19,458), using women with a first vaginal delivery as reference (n = 239,150). Risks were calculated as odds ratios by unconditional logistic regression analysis with 95% confidence intervals (95%) after adjustments for maternal, delivery, and infant characteristics.

MAIN OUTCOME MEASURES:

Retained placenta with normal (≤1000 ml) and heavy (>1000 ml) bleeding.

RESULTS:

The overall rate of retained placenta was 2.07%. In women with a previous caesarean section and in women with previous vaginal delivery, the corresponding rates were 3.44% and 1.96%, respectively. Compared with women with a previous vaginal delivery, women with a previous caesarean section had an increased risk of retained placenta (adjusted OR 1.45; 95% CI 1.32-1.59), and the association was more pronounced for retained placenta with heavy bleeding (adjusted OR 1.61; 95% CI 1.44-1.79).

CONCLUSIONS:

Our report shows an increased risk for retained placenta in women previously delivered by caesarean section, a finding that should be considered in discussions of mode of delivery.

• Authors: J Belachew, S Cnattingius, A Mulic-Lutvica, K Eurenius, O Axelsson, A K Wikström
• Journal: BJOG : an international journal of obstetrics and gynaecology (BJOG) Vol. 121 Issue 2 Pg. 224-9 (Jan 2014) ISSN: 1471-0528 [Electronic] England
• PMID: 24044730 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2013 Royal College of Obstetricians and Gynaecologists.

Topics

• Abortion, Spontaneous (epidemiology)
• Adult
• Age Factors
• Birth Weight
• Cesarean Section (statistics & numerical data)
• Cohort Studies
• Female
• Humans
• Infant, Newborn
• Labor, Induced (statistics & numerical data)
• Logistic Models
• Parity
• Placenta, Retained (epidemiology)
• Postpartum Hemorrhage (epidemiology)
• Pregnancy
• Registries
• Risk Assessment
• Sweden (epidemiology)