Identifying risk factors for peripartum cesarean hysterectomy. A population-based study

OBJECTIVE: To determine the incidence of, and obstetric risk factors for, emergency peripartum hysterectomy. STUDY DESIGN: A population-based study comparing all singleton deliveries between the years 1988 and 1999 that were complicated with peripartum hysterectomy to deliveries without this complication. Statistical analysis was performed with multiple logistic regression analysis. RESULTS: Emergency peripartum hysterectomy complicated 0.048% (n = 56) of deliveries in the study (n = 117,685). Independent risk factors for emergency peripartum hysterectomy from a backward, stepwise, multivariable logistic regression model were: uterine rupture (OR = 521.4, 95% CI 197.1-1379.7), placenta previa (OR = 8.2, 95% CI 2.2-31.0), postpartum hemorrhage (OR = 33.3, 95% CI 12.6-88.1), cervical tears (OR = 18.0, 95% CI 6.2-52.4), placenta accreta (OR = 13.2, 95% CI 3.5-50.0), second-trimester bleeding (OR = 9.5, 95% CI 2.3-40.1), previous cesarean section (OR = 6.9, 95% CI 3.7-12.8) and grand multiparity (> 5 deliveries) (OR = 3.4, 95% CI 1.8-6.3). Newborns delivered after peripartum hysterectomy had lower Apgar scores (< 7) at 1 and 5 minutes than did others (OR = 11.5, 95% CI 6.2-20.9 and OR = 27.4, 95% CI 11.2-67.4, respectively). In addition, higher rates of perinatal mortality were noted in the uterine hysterectomy vs. the comparison group (OR = 15.9, 95% CI 7.5-32.6). Affected women were more likely than the controls to receive packed-cell transfusions (OR = 457.7, 95% CI 199.2-1105.8) and had lower hemoglobin levels at discharge from the hospital (9.9 +/- 1.3 vs. 12.8 +/- 5.7, P < .001). CONCLUSION: Cesarean deliveries in patients with suspected placenta accreta, specifically those performed due to placenta previa in women with a previous uterine scar, should involve specially trained obstetricians. In addition, detailed informed consent about the possibility of emergency peripartum hysterectomy and its associated morbidity should be obtained.     

Risk Factors and Pregnancy Outcome in Different Types of Placenta Previa

ObjectiveTo compare risk factors and pregnancy outcome between different types of placenta previa (PP).Materials and MethodsWe conducted a retrospective study of 306 women presenting with PP over a 10-year period from January 1996 to December 2005. Differences between women with major and minor PP regarding age, parity, history of Caesarean section, antepartum hemorrhage, preterm deliveries, placenta accreta, Caesarean hysterectomy, operative complications, and neonatal outcome were identified using Mann-Whitney U test, chi-square test, and multivariate logistic regression.ResultsThe overall incidence of PP was 0.73%. Major PP (complete or partial PP) occurred in 173 women (56.5%) and minor PP (marginal PP or low-lying placenta) in 133 women (43.5%). There were no differences between women with major and minor PP regarding age, parity, and previous miscarriages. After controlling for confounding factors, women with major PP showed a significantly higher incidence of antepartum hemorrhage (OR 3.18; 95% CI 1.58–6.4, P = 0.001), placenta accreta (OR 3.2; 95% CI 1.22–8.33, P = 0.017), and hysterectomy (OR 5.1; 95% CI 1.31–19.86, P = 0.019). Antepartum hemorrhage in women with PP was associated with premature delivery (OR 14.9; 95% CI 4.9–45.1, P < 0.001), more commonly in women with major PP. The only significant difference between women with major and minor PP regarding neonatal outcome was that major PP was associated with a higher incidence of admission to the neonatal intensive care unit (P = 0.014).ConclusionComplete or partial placenta previa is associated with higher morbidity than marginal placenta previa or low-lying placenta.     

Real increasing incidence of hysterectomy for placenta accreta following previous caesarean section

Objective

Placenta accreta, morbid adherence to the uterus to the myometrium, is commonest in association with placenta previa in women previously delivered by caesarean section (CS). It has become proportionally a greater cause of major maternal morbidity and mortality as the frequency of other serious obstetric complications has declined. The aim of this study was to examine the incidence of placenta accreta in the context of a rising caesarean delivery rate.

Study design

Retrospective review of the incidence of placenta accreta in parous women during the 36 years 1975–2010. Cases were identified from hospital records and then correlated with pathological reports. The incidence of placenta accreta was analysed in the context of women previously delivered by CS.

Results

During the 36-year period in our unit, 157,162 multiparous women delivered, of whom 15,151 (9.6%) had a previous CS scar. The institutional incidence of CS rose from 4.1% in 1975 to 20.7% in 2010. Twenty-five parous women, all with a previous CS, had placenta accreta requiring hysterectomy. The overall incidence of placenta accreta was 1.65 per 1000 parous women with a previous CS, but was low (1.06/1000) until 2002. From 2003 to 2010 the incidence rose to 2.37/1000 previous CS deliveries (OR 2.2; 95% CI 1.05–5.1).

Conclusion

The frequency of placenta accreta correlated steadily with the CS rate until 2000. Since then, the incidence has nearly doubled in women with previous CS scars, suggesting an additional causative influence on risk.     

Risk factors for placenta accreta

OBJECTIVE: To identify risk factors associated with placenta accreta in a large cohort study. METHODS: Data for this study came from the Taiwan Down Syndrome Screening Group, an ongoing project on feasibility of serum screening in an Asian population. Women who had serum screening for Down syndrome at 14-22 weeks' gestation using alpha-fetoprotein (AFP) and free beta-hCG between January 1994 and June 1997, and delivered in the same institution, were included (n = 10,672). Those who had multiple gestations (n = 200), overt diabetes (n = 11), or fetal malformations (n = 101) were excluded. If a woman was involved more than once, one randomly selected pregnancy was included in the analysis (n = 9349). Twenty-eight pregnancies were complicated by placenta accreta, diagnosed by clinical presentation (n = 26) or histologic confirmation (n = 2). Multiple logistic regression with adjustment for potentially confounding variables was used to identify independent risk factors for placenta accreta. RESULTS: Women who had placenta previa (odds ratio [OR] 54.2; 95% confidence interval [CI] 17.8, 165.5) and second-trimester serum levels of AFP and free beta-hCG greater than 2.5 multiples of the median (OR 8.3; 95% CI 1.8, 39.3 and OR 3.9; 95% CI 1.5, 9.9, respectively), and were 35 years and older (OR 3.2; 95% CI 1.1, 9.4) were at increased risk of having placenta accreta. CONCLUSION: Risk factors for placenta accreta include placenta previa, abnormally elevated second-trimester AFP and free beta-hCG levels, and advanced maternal age.     

Placenta previa accreta

OBJECTIVES: The purpose of our study was to assess the relationship between previous cesarean section and placenta previa accreta and to estimate the incidence of placenta accreta et previa accreta as the indication for peripartum hysterectomy. MATERIALS AND METHODS: The records of all patients delivered with the diagnosis of placenta previa accreta during the period from 1992-2002 at Hospital in Chojnice were reviewed. Statistical analyses were carried out to determine the relationship between previous cesarean section and subsequent development of placenta previa accreta. We conducted a retrospective analysis of indications for peripartum hysterectomy. RESULTS: From a total 28,177 women, who delivered at the Chojnice Hospital, 15(0.05%) patients had placenta accreta, 63(0.2%) placenta previa. Among placenta previa deliveries 22(34.9%) patients had previous cesarean section. Out of 15 patients with placenta accreta 10(66.7%) had placenta previa. Incidence of placenta accreta per case of placenta previa was 158.7 per 1000. The incidence of placenta previa accreta significantly increased in those with previous post cesarean scars. This incidence increased as the number of previous cesarean sections increased. The most common indication for peripartum hysterectomy was placenta accreta--48.4%, incidence of placenta previa accreta was accounts for 32.3% of all indications. CONCLUSIONS: The association between placenta previa accreta and prior cesarean section was confirmed. The incidence of placenta accreta increased as the number of previous cesarean sections increased. Patients with an antepartum diagnosis of placenta previa, who have had a previous cesarean section should be considered at high risk for developing placenta accreta. The most common indication for peripartum hysterectomy in this study was placenta previa accreta.     

Placenta previa: obstetric risk factors and pregnancy outcome

Objective: To determine the incidence, obstetric risk factors and perinatal outcome of placenta previa. Study design: All singleton deliveries at our institution between 1990 and 1998 complicated with placenta previa were compared with those without placenta previa. Results: Placenta previa complicated 0.38% ( n = 298) of all singleton deliveries ( n = 78 524). A back-step multiple logistic regression model found the following factors to be independently correlated with the occurrence of placenta previa: maternal age above 40 years (OR 3.1, 95% CI 2.0-4.9), infertility treatments (OR 3.1, 95% CI 1.8-5.6), a previous Cesarean section (OR 1.8, 95% CI 1.4-2.4), a history of habitual abortions (OR 1.3, 95% CI 1.3-2.7) and Jewish ethnicity (OR 1.3, 95% CI 1.1-1.8). Pregnancies complicated with placenta previa had significantly higher rates of second-trimester bleeding (OR 156.0, 95% CI 87.2-277.5), pathological presentations (OR 7.6, 95% CI 5.7-10.1), abruptio placentae (OR 13.1, 95% CI 8.2-20.7), congenital malformations (OR 2.6, 95% CI 1.5-4.2), perinatal mortality (OR 2.6, 95% CI 1.1-5.6), Cesarean delivery (OR 57.4, 95% CI 40.7-81.4), Apgar scores at 5 min lower than 7 (OR 4.4, 95% CI 2.3-8.3), placenta accreta (OR 3.6, 95% CI 1.1-9.9) postpartum hemorrhage (OR 3.8, 95% CI 1.2-10.5), postpartum anemia (OR 5.5, 95% CI 4.4-6.9) and delayed maternal and infant discharge from the hospital (OR 10.9, 95% CI 7.3-16.1) as compared to pregnancies without placenta previa. In a multivariable analysis investigating risk factors for perinatal mortality, the following were found to be independent significant factors: congenital malformations, placental abruption, pathological presentations and preterm delivery. In contrast, placenta previa and Cesarean section were found to be protective factors against the occurrence of perinatal mortality while controlling for confounders. Conclusion: Although an abnormal implantation per se was not an independent risk factor for perinatal mortality, placenta previa should be considered as a marker for possible obstetric complications. Hence, the detection of placenta previa should encourage a careful evaluation with timely delivery in order to reduce the associated maternal and perinatal complications.     

Placenta previa: obstetric risk factors and pregnancy outcome.

OBJECTIVE: To determine the incidence, obstetric risk factors and perinatal outcome of placenta previa. STUDY DESIGN: All singleton deliveries at our institution between 1990 and 1998 complicated with placenta previa were compared with those without placenta previa. RESULTS: Placenta previa complicated 0.38% (n = 298) of all singleton deliveries (n = 78 524). A back-step multiple logistic regression model found the following factors to be independently correlated with the occurrence of placenta previa: maternal age above 40 years (OR 3.1, 95% CI 2.0-4.9), infertility treatments (OR 3.1, 95% CI 1.8-5.6), a previous Cesarean section (OR 1.8, 95% CI 1.4-2.4), a history of habitual abortions (OR 1.3, 95% CI 1.3-2.7) and Jewish ethnicity (OR 1.3, 95% CI 1.1-1.8). Pregnancies complicated with placenta previa had significantly higher rates of second-trimester bleeding (OR 156.0, 95% CI 87.2-277.5), pathological presentations (OR 7.6, 95% CI 5.7-10.1), abruptio placentae (OR 13.1, 95% CI 8.2-20.7), congenital malformations (OR 2.6, 95% CI 1.5-4.2), perinatal mortality (OR 2.6, 95% CI 1.1-5.6), Cesarean delivery (OR 57.4, 95% CI 40.7-81.4), Apgar scores at 5 min lower than 7 (OR 4.4, 95% CI 2.3-8.3), placenta accreta (OR 3.6, 95% CI 1.1-9.9) postpartum hemorrhage (OR 3.8, 95% CI 1.2-10.5), postpartum anemia (OR 5.5, 95% CI 4.4-6.9) and delayed maternal and infant discharge from the hospital (OR 10.9, 95% CI 7.3-16.1) as compared to pregnancies without placenta previa. In a multivariable analysis investigating risk factors for perinatal mortality, the following were found to be independent significant factors: congenital malformations, placental abruption, pathological presentations and preterm delivery. In contrast, placenta previa and Cesarean section were found to be protective factors against the occurrence of perinatal mortality while controlling for confounders. CONCLUSION: Although an abnormal implantation per se was not an independent risk factor for perinatal mortality, placenta previa should be considered as a marker for possible obstetric complications. Hence, the detection of placenta previa should encourage a careful evaluation with timely delivery in order to reduce the associated maternal and perinatal complications.     

Early preterm delivery due to placenta previa is an independent risk factor for a subsequent spontaneous preterm birth

ABSTRACT: BACKGROUND: To determine whether patients with placenta previa who delivered preterm have an increased risk for recurrent spontaneous preterm birth. METHODS: This retrospective population based cohort study included patients who delivered after a primary cesarean section (n = 9983). The rate of placenta previa, its recurrence, and the risk for recurrent preterm birth were determined. RESULTS: Patients who had a placenta previa at the primary CS pregnancy had an increased risk for its recurrence [crude OR of 2.65 (95 % CI 1.3-5.5)]. The rate of preterm birth in patients with placenta previa in the primary CS pregnancy was 55.9 %; and these patients had a higher rate of recurrent preterm delivery than the rest of the study population (p < .001). Among patients with placenta previa in the primary CS pregnancy, those who delivered preterm had a higher rate of recurrent spontaneous preterm birth regardless of the location of their placenta in the subsequent delivery [OR 3.09 (95 % CI 2.1-4.6)]. In comparison to all patients with who had a primary cesarean section, patients who had placenta previa and delivered preterm had an independent increased risk for recurrent preterm birth [OR of 3.6 (95 % CI 1.52-8.51)]. CONCLUSIONS: Women with placenta previa, who deliver preterm, especially before 34 weeks of gestation, are at increased risk for recurrent spontaneous preterm birth regardless to the site of placental implantation in the subsequent pregnancy. Thus, strict follow up by high risk pregnancies specialist is recommended.     

Complete versus incomplete placenta previa and obstetric outcome.

OBJECTIVE: To compare obstetric outcome in women with complete versus incomplete placenta previa (PP). METHODS: A 10-year retrospective case-control study was conducted between 1992 and 2001. A 202 singleton pregnancies with PP were analyzed. RESULTS: The incidence of PP was 0.4%. Complete PP comprised 32.7% and incomplete PP 67.3% of cases. No difference was observed in the frequency of antepartum hemorrhage. Women with complete PP had significantly higher requirement for antepartum and postpartum transfusions, higher frequency of postpartum hemorrhage and postpartum hysterectomy. The risk for placenta accreta was increased in complete PP group even after controlling for confounding factors (adjusted OR=3.75, 95% CI=1.11-12.68, p<0.05). No difference in the frequency of preterm delivery was found between the groups. Term infants of mothers with complete PP had significantly lower birth weight (3205 vs. 3360, p=0.04). CONCLUSION: Complete PP is a high-risk subgroup of PP associated with higher maternal morbidity in comparison to incomplete PP.     

Abnormal placentation: twenty-year analysis

OBJECTIVE: This study was undertaken to determine whether the rate of abnormal placentation is increasing in conjunction with the cesarean rate and to evaluate incidence, risk factors, and outcomes. STUDY DESIGN: Cases from 1982-2002 were identified by histopathologic or strong clinical criteria. Risk factors were assessed in a matched case-control study, and analyzed using conditional logistic regression models. RESULTS: There were 64,359 deliveries, with cesarean rates increasing from 12.5% (1982) to 23.5% (2002). The overall incidence of placenta accreta was 1 in 533. Significant risk factors for placenta accreta in our final analysis included advancing maternal age (odds ratio [OR] 1.13, 95% CI 1.089-1.194, P < .0001), 2 or more cesarean deliveries (OR 8.6, 95% CI 3.536-21.078, P < .0001), and previa (OR 51.4, 95% CI: 10.646-248.390, P < .0001). CONCLUSION: The rate of placenta accreta increased in conjunction with cesarean deliveries; the most important risk factors were previous cesarean delivery, previa, and advanced maternal age.     

Emergency peripartum hysterectomy: experience at a community teaching hospital

OBJECTIVES: To estimate the incidence, indications, risk factors, and complications associated with emergency peripartum hysterectomy at a community-based academic medical center. METHODS: We analyzed retrospectively 47 of 48 cases of emergency peripartum hysterectomy performed at Winthrop-University Hospital from 1991 to 1997. Emergency peripartum hysterectomy was defined as one performed for hemorrhage unresponsive to other treatment less than 24 hours after delivery. Fisher exact test, Wilcoxon rank sum test, and Cochran-Armitage exact trend test were used for analysis. RESULTS: There were 48 emergency peripartum hysterectomies among 34,241 deliveries for a rate of 1.4 per 1000. Most frequent indications were placenta accreta (48.9%, 12 with previa, 11 without previa), uterine atony (29.8%), previa without accreta (8.5%), and uterine laceration (4.3%). Placenta accreta was the most common indication in multiparous women (58.8%, 20 of 34), uterine atony the most common in primiparas (69.2%, nine of 13). Twenty-two of 23 (95.6%) women with placenta accreta had a previous cesarean delivery or curettage. The number of cesarean deliveries or curettages increased the risk of placenta accreta proportionally. Thirty-eight (80.9%) of the hysterectomies were subtotal. Postoperative febrile morbidity was 34%; other morbidity was 26.3%. CONCLUSION: Placenta accreta has become the most common indication for emergency peripartum hysterectomy.     

The relationship of placenta previa and history of induced abortion.

OBJECTIVES: We evaluated the risk of placenta previa being associated with a history of induced abortion by different surgical procedures. METHODS: Cases (n=192) were women who had a singleton delivery complicated by placenta previa at a major obstetric care hospital in western Washington state between April 1, 1990 and December 31, 1992. Controls (n=622) were women with singleton deliveries not complicated by placenta previa or abruption. Odds ratios, determined by logistic regression, approximate the relative risks. RESULTS: Vacuum aspiration abortion was not associated with an increased risk of placenta previa (OR 0.9, 95% CI 0.6-1.5). However, the risk of placenta previa increased with the number of sharp curettage abortions (OR 2.9, 95% CI 1.0-8.5 for > or =3). CONCLUSIONS: Risk of placenta previa may be increased in a dose response fashion by multiple sharp curettage abortions. However, vacuum aspiration does not confer an increased risk, and may be a better alternative.     

胎盘植入性疾病的危险因素及妊娠结局分析

目的探讨胎盘植入性疾病的危险因素及妊娠结局。 方法回顾性分析2009年1月至2017年12月广州医科大学附属第三医院/广州重症孕产妇救治中心围产资料数据库中信息完整的单胎妊娠孕妇48 650例临床资料,将这些孕妇分为胎盘植入性疾病组和非胎盘植入性疾病组,分析胎盘植入性疾病的危险因素及其妊娠结局。 结果单因素分析显示,年龄≥35岁、高中教育水平及以下、孕次≥3次、经产妇、人工流产史、剖宫产史、体外受精－胚胎移植受孕、合并前置胎盘是胎盘植入性疾病的相关危险因素(P<0.05)。多因素logistic回归分析显示,胎盘植入性疾病的独立危险因素为剖宫产史(OR＝2.254,95%CI：1.917～2.650)、体外受精－胚胎移植受孕(OR＝1.591,95%CI：1.212～2.089)、合并前置胎盘(OR＝28.282,95%CI：24.338～32.866);与非胎盘植入性疾病产妇相比,患有胎盘植入性疾病产妇早产、剖宫产、产后出血、弥散性血管内凝血、产褥期感染、子宫切除、低出生体重儿、新生儿Apgar评分相对较低(1 min)、产妇入住重症监护病房的发生率明显升高(P<0.05)。 结论剖宫产史、辅助生殖受孕、合并前置胎盘是引起胎盘植入性疾病的独立危险因素,胎盘植入性疾病的妊娠结局不良。     

Association between maternal serum alpha-fetoprotein and adverse outcomes in pregnancies with placenta previa

OBJECTIVE: To determine whether increased maternal serum alpha-fetoprotein (MSAFP) level at 15-20 weeks' gestation is a marker of adverse outcomes in women with placenta previa at delivery. METHODS: We conducted a retrospective cohort study of singleton pregnancies complicated by placenta previa, diagnosed sonographically, and confirmed at delivery. All women had MSAFP screening at 15-20 weeks' gestation and delivered nonanomalous live-born infants at or after 24 weeks' gestation. RESULTS: One hundred seven women with placenta previa delivered during the study. Fourteen (13%, 95% CI 7%, 21%) had MSAFP at least 2.0 multiples of the median (MoM). They were significantly more likely than those with lower MSAFP levels to have one or more of the following outcomes: hospitalization for antepartum bleeding before 30 weeks' gestation (50% versus 15%), delivery before 30 weeks' gestation (29% versus 5%), or preterm delivery for pregnancy-associated hypertension before 34 weeks' gestation (14% versus none). The MSAFP cutoff of 2.0 MoM provided the best combination of sensitivity and specificity for those outcomes, using receiver operating characteristic curves. CONCLUSION: Women with placenta previa who also have high MSAFP levels are at increased risk of bleeding in the early third trimester and preterm birth. We did not find women who required cesarean hysterectomy, including those with placenta accreta, to consistently have elevated MSAFP.     

Peripartum cesarean hysterectomy: critical analysis of risk factors and trends over the years

Objective.?To investigate time trends and risk factors for peripartum cesarean hysterectomy.

Methods.?A population-based study comparing all deliveries that were complicated with peripartum hysterectomy to deliveries without this complication was conducted. Deliveries occurred during the years 1988–2007 at a tertiary medical center. A multiple logistic regression model was constructed to find independent risk factors associated with peripartum hysterectomy.

Results.?Emergency peripartum cesarean hysterectomy complicated 0.06% (n?=?125) of all deliveries in the study period (n?=?211,815). The incidence of peripartum hysterectomy increased over time (1988–1994, 0.04%; 1995–2000, 0.05%; 2001–2007, 0.095%). Independent risk factors for emergency peripratum hysterectomy from a backward, stepwise, multivariable logistic regression model were: uterine rupture (OR?=?487; 95% CI 257.8–919.8, p?<?0.001), placenta previa (OR?=?66.4; 95% CI 39.8–111, p?<?0.001), postpartum hemorrhage (PPH) (OR?=?40.8; 95% CI 22.4–74.6, p?<?0.001), cervical tears (OR?=?22.3; 95% CI 10.4–48.1, p?<?0.001), second trimester bleeding (OR?=?6; 95% CI 1.8–20, p?=?0.003), previous cesarean delivery (OR?=?5.4; 95% CI 3.5–8.4, p?<?0.001), placenta accreta (OR?=?4.7; 95% CI 1.9–11.7, p?=?0.001), and grand multiparity (above five deliveries, OR?=?4.1; 95% CI 2.5–6.6, p?<?0.001). Newborns of these women had lower Apgar scores (<7) at 1 and 5?min (32.7% vs.4.4%; p?<?0.001, and 10.5% vs. 0.6%; p?<?0.001, respectively), and higher rates of perinatal mortality (18.4% vs. 1.4%; p?<?0.001) as compared to the comparison group.

Conclusion.?Significant risk factors for peripartum hysterectomy are uterine rupture, placenta previa, PPH, cervical tears, previous cesarean delivery, placenta accreta, and grand multiparity. Since the incidence rates are increasing over time, careful surveillance is warranted. Cesarean deliveries in patients with placenta previa-accreta, specifically those performed in women with a previous cesarean delivery, should involve specially trained obstetricians, following informed consent regarding the possibility of peripartum hysterectomy.     

Prediction of peripartum hysterectomy and end organ dysfunction in major obstetric haemorrhage

Objectives

The aims of this study are to determine the incidence and aetiology of major obstetric haemorrhage (MOH) in our population, to examine the success rates of medical and surgical interventions and to identify risk factors for peripartum hysterectomy and end organ dysfunction (EOD).

Study design

This prospective study from 2004 to 2007 was carried out in three Dublin maternity hospitals. Women were identified as having MOH if they received ≥5 units of red cell concentrate (RCC) acutely. Risk factors for hysterectomy or end organ dysfunction were calculated using logistic regression.

Results

One hundred and seventeen cases of MOH in 93,291 deliveries were identified (1.25/1000). The predominant cause was uterine atony. Haemostasis was achieved with medical therapy alone in 15% of cases. The hydrostatic balloon and the B-Lynch suture arrested bleeding in 75% and 40% of cases utilised respectively. Hysterectomy was required to arrest bleeding in 24% of women and 16% of women developed end organ dysfunction (11 had both). There was one maternal death. Independent risk factors for hysterectomy included the number of previous caesarean sections (OR 3.28, 95% CI 1.95-5.5), placenta praevia (OR 13.5, 95% CI 7.7-184), placenta accreta (OR 37.7, 95% CI 7.7-184), uterine rupture (OR 7.25, 95% CI 1.25-42) and the number of units of RCC transfused (OR 1.31, 95% CI 1.13-1.5). Independent risk factors for end organ dysfunction (EOD) were placenta accreta (OR 5, 95% CI 1.5-16.5), uterine rupture (OR 13.86, 95% CI 2.32-82), the number of RCC transfused (OR 1.31, 95% CI 1.13-1.5) and the minimum haematocrit recorded (OR 5.53, 95% CI 1.7-18).

Conclusions

MOH is complicated by hysterectomy in 24% and end organ dysfunction in 16% of cases. The risk of peripartum hysterectomy is increased with the number of previous caesarean sections, the aetiology of the bleed, namely placenta praevia/accreta or uterine rupture and the volume of blood transfused. Critically, failure to maintain optimal haematocrit during the acute event was associated with end organ dysfunction.     

Placenta previa and antepartum hemorrhage after previous cesarean section

A prospective study was conducted to determine the risk of placenta previa and unexplained antepartum hemorrhage after a previous cesarean section (CS). Of a total of 24,644 patients, 81 (0.33%) had a placenta previa which demanded abdominal delivery. The risk of placenta previa was 0.25% with an unscarred uterus and 1.22% in patients with one or more previous CS (the difference was statistically significant p less than 0.001). The corresponding figures for unexplained antepartum hemorrhage were 0.40% and 3.81%, respectively (p less than 0.001). Patients presenting with a placenta previa and a scarred uterus had a 16% risk of undergoing cesarean hysterectomy because of placenta accreta and severe hemorrhage compared to 3.6% in patients with placenta previa and an unscarred uterus. In conclusion, cesarean deliveries predispose to placenta previa, placenta accreta and antepartum hemorrhage during subsequent pregnancies. This relationship has to be considered in the cost-benefit equation for decision of route of delivery.     

Placenta previa and maternal hemorrhagic morbidity

Objective: Placenta previa is associated with maternal hemorrhage, but most literature focuses on morbidity in the setting of placenta accreta. We aim to characterize maternal morbidity associated with previa and to define risk factors for hemorrhage.

Methods: This is a secondary cohort analysis of the NICHD Maternal–Fetal Medicine Units Network Cesarean Section Registry. This analysis included all women undergoing primary Cesarean delivery without placenta accreta. About 496 women with previa were compared with 24,201 women without previa. Primary outcome was composite maternal hemorrhagic morbidity. Non-hemorrhagic morbidities and risk factors for hemorrhage were also evaluated.

Results: Maternal hemorrhagic morbidity was more common in women with previa (19 versus 7%, aRR 2.6, 95% CI 1.9–3.5). Atony requiring uterotonics (aRR 3.1, 95% CI 2.0–4.9), red blood cell transfusion (aRR 3.8, 95% CI 2.5–5.7), and hysterectomy (aRR 5.1, 95% CI 1.5–17.3) were also more common with previa. For women with previa, factors associated with maternal hemorrhage were pre-delivery anemia, thrombocytopenia, diabetes, magnesium use, and general anesthesia.

Conclusion: Placenta previa is an independent risk factor for maternal hemorrhagic morbidity. Some risk factors are modifiable, but many are intrinsic to the clinical scenario.     

Risk factors for placenta previa in an Asian population.

OBJECTIVE: To identify the risk factors for placenta previa in an Asian population. METHODS: This retrospective cohort study involved Taiwanese women delivered between July 1990 and December 2003 at Chang Gung Memorial Hospital, Taipei, Taiwan. Pregnancies complicated by multiple gestation and fetal anomalies were excluded. RESULTS: There were 457 cases of placenta previa (1.2%) among the 37,702 pregnancies analyzed. Risk factors for placenta previa included a prior preterm birth (OR, 6.6; 95% confidence interval [CI], 4.1-10.6); technology-assisted conception (OR, 4.8; 95% CI, 2.9-7.8); smoking (OR, 3.3; 95% CI, 1.2-9.1) or working (OR, 3.8; 95% CI, 2.8-5.3) during pregnancy; maternal age of, or greater than 35 years (OR, 2.0 to 2.2; 95% CI, 1.3-3.7); and previous induced abortions (OR, 1.3-3.0; 95% CI, 1.1-7.1). CONCLUSION: The risk factors for placenta previa were found to be the same for Asian women as those previously recorded for American and European women, but additional factors were detected.