Risk of placenta previa in second birth after first birth cesarean section: a population-based study and meta-analysis.

OBJECTIVE: To compare the risk of placenta previa at second birth among women who had a cesarean section (CS) at first birth with women who delivered vaginally. METHODS: Retrospective cohort study of 399,674 women who gave birth to a singleton first and second baby between April 2000 and February 2009 in England. Multiple logistic regression was used to adjust the estimates for maternal age, ethnicity, deprivation, placenta previa at first birth, inter-birth interval and pregnancy complications. In addition, we conducted a meta-analysis of the reported results in peer-reviewed articles since 1980. RESULTS: The rate of placenta previa at second birth for women with vaginal first births was 4.4 per 1000 births, compared to 8.7 per 1000 births for women with CS at first birth. After adjustment, CS at first birth remained associated with an increased risk of placenta previa (odds ratio = 1.60; 95% CI 1.44 to 1.76). In the meta-analysis of 37 previously published studies from 21 countries, the overall pooled random effects odds ratio was 2.20 (95% CI 1.96-2.46). Our results from the current study is consistent with those of the meta-analysis as the pooled odds ratio for the six population-based cohort studies that analyzed second births only was 1.51 (95% CI 1.39-1.65). CONCLUSIONS: There is an increased risk of placenta previa in the subsequent pregnancy after CS delivery at first birth, but the risk is lower than previously estimated. Given the placenta previa rate in England and the adjusted effect of previous CS, 359 deliveries by CS at first birth would result in one additional case of placenta previa in the next pregnancy.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

The timing of elective caesarean delivery between 2000 and 2009 in England

BACKGROUND: In 2004, the National Institute for Clinical Excellence (NICE) recommended that an elective caesarean section for an uncomplicated pregnancy should not be carried out before 39 completed weeks due to increased risk of respiratory morbidity in newborns. We describe the trends and variation across 63 English NHS trusts in the timing of elective caesarean section (CS) for low-risk singleton deliveries. METHODS: We identified elective CS deliveries between 1st April 2000 and 28th February 2009 in English NHS trusts using the Hospital Episode Statistics. We selected women with uncomplicated pregnancies who had an elective CS delivery after 34 completed weeks of gestation, and analysed the trends and the trust-level variation in the timing of elective CS. The impact of the NICE guidance on the monthly rate of elective CS deliveries performed after 39 weeks was estimated using an interrupted time-series design with autoregressive integrated moving average (ARIMA). RESULTS: There were 118,456 elective CS deliveries at the 63 NHS trusts. The overall proportion of elective CS deliveries done after 39 completed weeks steadily increased from 39% in 2000/01 to 63% in 2008/09. The proportions rose from 43% to 67% for women with breech presentation and from 35% to 62% for women with a previous CS. There was significant variation across NHS trusts in each year; in 2008/09, with the proportions of elective CS done after 39 weeks ranging from 28% to 89% (Inter-quartile range limits: 54% to 72%). We found a small but statistically significant increase in the proportion immediately after the publication of the NICE guidance, but its rate of growth rate declined slightly thereafter. CONCLUSIONS: NHS trusts in our study have responded to the new evidence on the benefits of delaying elective CS to after 39 weeks gestation. However, substantial differences between NHS trusts remain, which indicates there is room for further improvement. We suggest that maternity services and commissioners adopt the "timing of elective caesarean" as a quality indicator to support clinical practice

Maternal morbidity associated with placenta praevia among women who had elective caesarean section.

OBJECTIVE: Estimates of the increased risk of maternal complications after caesarean section posed by placenta praevia differ between studies and may not reflect current practice. We assess the impact of placenta praevia on maternal complications after elective caesarean section (CS). STUDY DESIGN: We undertook a retrospective cohort study of women who had an elective CS for a singleton at term in the English National Health Service between 1 April 2000 and 28 February 2009 using routine data from the Hospital Episode Statistics database. Multiple logistic regression was used to estimate the effect of placenta praevia on maternal complications after controlling for maternal age, parity, whether a woman had a previous CS, and gestational age. Maternal complications included postpartum haemorrhage, obstetric trauma, blood transfusion and hysterectomy. RESULTS: Among 131,731 women having an elective CS for a singleton, 4,332 (3.3%) women had placenta praevia. Placenta praevia increased the risk of postpartum haemorrhage from 9.7% to 17.5% (adjusted odds ratio (OR) 1.91; 95% CI: 1.74 to 2.09), the risk of blood transfusion from 1.4% to 6.4% (OR 4.39; 3.76 to 5.12), and the risk of hysterectomy from 0.03% to 1% (OR 39.70; 22.42 to 70.30). Previous studies have estimated the rate of hysterectomy among women with placenta praevia to be 5%. CONCLUSION: Placenta praevia remains a risk factor for various maternal complications, although the increased risk of hysterectomy is lower than previously reported

Risk of placenta previa in second birth after first birth cesarean section: a population-based study and meta-analysis

Abstract Background Objective: To compare the risk of placenta previa at second birth among women who had a cesarean section (CS) at first birth with women who delivered vaginally. Methods Retrospective cohort study of 399,674 women who gave birth to a singleton first and second baby between April 2000 and February 2009 in England. Multiple logistic regression was used to adjust the estimates for maternal age, ethnicity, deprivation, placenta previa at first birth, inter-birth interval and pregnancy complications. In addition, we conducted a meta-analysis of the reported results in peer-reviewed articles since 1980. Results The rate of placenta previa at second birth for women with vaginal first births was 4.4 per 1000 births, compared to 8.7 per 1000 births for women with CS at first birth. After adjustment, CS at first birth remained associated with an increased risk of placenta previa (odds ratio = 1.60; 95% CI 1.44 to 1.76). In the meta-analysis of 37 previously published studies from 21 countries, the overall pooled random effects odds ratio was 2.20 (95% CI 1.96-2.46). Our results from the current study is consistent with those of the meta-analysis as the pooled odds ratio for the six population-based cohort studies that analyzed second births only was 1.51 (95% CI 1.39-1.65). Conclusions There is an increased risk of placenta previa in the subsequent pregnancy after CS delivery at first birth, but the risk is lower than previously estimated. Given the placenta previa rate in England and the adjusted effect of previous CS, 359 deliveries by CS at first birth would result in one additional case of placenta previa in the next pregnancy.</p