Minna Tikkanen

Clinical presentation and risk factors of placental abruption

Background. To study the risk factors of placental abruption during the index pregnancy. Methods. One hundred and ninety‐eight women with placental abruption and 396 control women were identified among 46,742 women who delivered at a tertiary referral university hospital between 1997 and 2001. Clinical variables were compared between the groups. Multivariate logistic regression analysis was applied to identify independent risk factors. The clinical manifestations of placental abruption were also studied. Results. The overall incidence of placental abruption was 0.42%. The independent risk factors were maternal (adjusted OR 1.8; 95% CI 1.1, 2.9) and paternal smoking (2.2; 1.3, 3.6), use of alcohol (2.2; 1.1, 4.4), placenta previa (5.7; 1.4, 23.1), pre‐eclampsia (2.7; 1.3, 5.6), and chorioamnionitis (3.3; 1.0, 10.0). Vaginal bleeding (70%), abdominal pain (51%), bloody amniotic fluid (50%), and fetal heart rate abnormalities (69%) were the most common manifestations. Neither bleeding nor pain was present in 19% of the cases. Overall, 59% had preterm labor (OR 12.9; 95% CI 8.3, 19.8), and 91% were delivered by cesarean section (34.7; 20.0, 60.1). Of the newborns, 25% were growth restricted. The perinatal mortality rate was 9.2% (OR 10.1; 95% CI 3.4, 30.1). Retroplacental blood clot was seen by ultrasound in 15% of the cases. Conclusions. Maternal alcohol consumption and smoking, and smoking by the partner turned out to be independent risk factors for placental abruption. Smoking by both partners multiplied the risk. The liberal use of ultrasound examination contributed little to the management of women with placental abruption.

Placental abruption: epidemiology, risk factors and consequences.

Placental abruption, classically defined as a premature separation of the placenta before delivery, is one of the leading causes of vaginal bleeding in the second half of pregnancy. Approximately 0.4–1% of pregnancies are complicated by placental abruption. The prevalence is lower in the Nordic countries (0.38–0.51%) compared with the USA (0.6–1.0%). Placental abruption is also one of the most important causes of maternal morbidity and perinatal mortality. Maternal risks include obstetric hemorrhage, need for blood transfusions, emergency hysterectomy, disseminated intravascular coagulopathy and renal failure. Maternal death is rare but seven times higher than the overall maternal mortality rate. Perinatal consequences include low birthweight, preterm delivery, asphyxia, stillbirth and perinatal death. In developed countries, approximately 10% of all preterm births and 10–20% of all perinatal deaths are caused by placental abruption. In many countries, the rate of placental abruption has been increasing. Although several risk factors are known, the etiopathogenesis of placental abruption is multifactorial and not well understood.

Antenatal diagnosis of placenta accreta leads to reduced blood loss.

Objective. Placenta accreta is one of the most devastating pregnancy complications. We sought to compare outcomes between women with placenta accreta when diagnosed antenatally or intrapartum, and to define predictors of the antenatal diagnosis. Design. Retrospective case–control study. Setting. University teaching hospital. Population. Twenty‐four women with placenta accreta diagnosed antenatally and 20 women discovered intrapartum. Methods. Chart review of historical and delivery‐associated variables. Rates were compared between the groups. Main Outcome Measures. Placenta accreta diagnosed antenatally or intrapartum. Results. Women with antenatal diagnosis had a lower estimated blood loss of a median of 4500ml (range 100–15000ml) compared with 7800ml (range 2500–17000ml, p=0.012) and required fewer units of packed red blood cells transfused (median 7; range 0–27 compared with 13.5; range 4–31, p=0.026). Nineteen (79%) women diagnosed antenatally had balloon catheter occlusion carried out during the cesarean section. Five (21%) had the entire placenta left in situ. There was no difference in the rate of surgical complications or duration of hospitalization. The clinical diagnosis among women with antenatal diagnosis was more often placenta percreta (p=0.013). The risk factor profile of women with antenatal diagnosis of placenta accreta included higher gravidity (p=0.014) and parity (p<0.0001), history of cesarean section (p=0.004), and placenta previa in the current pregnancy (p<0.001). Conclusions. Antenatal diagnosis of placenta accreta may reduce peripartum blood loss and the need for blood transfusion. Women with antenatal diagnosis more often have placenta previa and history of previous cesarean section, and the clinical diagnosis is more often placenta percreta.

Use of Bakri balloon tamponade in the treatment of postpartum hemorrhage: a series of 50 cases from a tertiary teaching hospital

Objective. Massive postpartum hemorrhage (PPH) is one of the most serious complications during delivery. Hysterectomy is commonly performed when other conventional treatment attempts fail. Bakri balloon tamponade (BBT) is a novel conservative management option for PPH. Little is known of the effectiveness of this procedure. We report a large case series from a tertiary teaching hospital. Design. Retrospective case series (October 2008–June 2011). Setting. University teaching hospital. Population. Forty‐four women with massive PPH (blood loss >1000 mL) and six other women with expected high risk of PPH (blood loss <1000 mL) managed by BBT. Methods. Chart review. Main outcome measures. Achievement of definitive hemostasis by BBT among the study population. Results. Among the women treated with BBT, the cause of PPH was uterine atony (16%), cervical rupture (14%), vaginal rupture and/or paravaginal hematoma (22%), placenta previa (18%) and placental retention (30%). The overall success rate was 86%. Seven of the 50 patients needed additional procedures. Of the seven failures, supravaginal uterine amputation or hysterectomy was required in four cases and embolization of the uterine arteries in three cases. Conclusions. BBT is a simple, readily available, effective and safe procedure for the management of PPH in selective cases. BBT does not exclude the use of other procedures if necessary. Even if BBT failed, it may provide temporary tamponade and time to prepare for other interventions or transportation from local hospital to tertiary centre. We suggest that BBT should be included in the PPH protocol.

Prepregnancy risk factors for placental abruption

Background. To define the prepregnancy risk factors for placental abruption. Methods. One hundred and ninety‐eight women with placental abruption and 396 control women without placental abruption were retrospectively identified among 46,742 women who delivered at a tertiary referral university hospital between 1997 and 2001. Relevant historical and clinical variables were compared between the groups. Multivariate logistic regression analysis was applied to identify independent risk factors. Results. The overall incidence of placental abruption was 0.42%. Placental abruption recurred in 8.8% of the cases. The independent risk factors were smoking (OR 1.7; 95% CI 1.1, 2.7), uterine malformation (OR 8.1; 1.7, 40), previous cesarean section (OR 1.7; 1.1, 2.8), and history of placental abruption (OR 4.5; 1.1, 18). Conclusions. Although univariate analysis identified many risk factors, only smoking, uterine malformation, previous cesarean section, and history of placental abruption remained significant after multivariate analysis, increasing the risk of placental abruption in subsequent pregnancy. It may be possible to approximate the risk for placental abruption based on these simple prepregnancy risk factors.

An international contrast of rates of placental abruption: An age-period-cohort analysis

Background Although rare, placental abruption is implicated in disproportionately high rates of perinatal morbidity and mortality. Understanding geographic and temporal variations may provide insights into possible amenable factors of abruption. We examined abruption frequencies by maternal age, delivery year, and maternal birth cohorts over three decades across seven countries. Methods Women that delivered in the US (n = 863,879; 1979–10), Canada (4 provinces, n = 5,407,463; 1982–11), Sweden (n = 3,266,742; 1978–10), Denmark (n = 1,773,895; 1978–08), Norway (n = 1,780,271, 1978–09), Finland (n = 1,411,867; 1987–10), and Spain (n = 6,151,508; 1999–12) were analyzed. Abruption diagnosis was based on ICD coding. Rates were modeled using Poisson regression within the framework of an age-period-cohort analysis, and multi-level models to examine the contribution of smoking in four countries. Results Abruption rates varied across the seven countries (3–10 per 1000), Maternal age showed a consistent J-shaped pattern with increased rates at the extremes of the age distribution. In comparison to births in 2000, births after 2000 in European countries had lower abruption rates; in the US there was an increase in rate up to 2000 and a plateau thereafter. No birth cohort effects were evident. Changes in smoking prevalence partially explained the period effect in the US (P = 0.01) and Sweden (P<0.01). Conclusions There is a strong maternal age effect on abruption. While the abruption rate has plateaued since 2000 in the US, all other countries show declining rates. These findings suggest considerable variation in abruption frequencies across countries; differences in the distribution of risk factors, especially smoking, may help guide policy to reduce abruption rates.

Decreasing perinatal mortality in placental abruption.

Objective. To study perinatal mortality associated with placental abruption. Design. Retrospective population study using the Finnish Hospital Discharge Register and Medical Birth Register data. Setting. Finland, 1987–2005. Population. Pregnancies with placental abruption and all other births without placental abruption. Methods. The national Hospital Discharge Register and Medical Birth Register were used to identify all pregnancies with placental abruption. Demographic data and delivery outcomes were collected retrospectively. Perinatal mortality associated with placental abruption was compared with that in other births. Potential risk factors were analysed. Main outcome measures. Perinatal mortality in placental abruption. Results. The study consisted of 618 735 women with 1.14 million pregnancies, 4336 of whom had placental abruption. Overall perinatal mortality with abruption was 119 per 1000 births. Placental abruption explained 7% of all perinatal deaths. The mortality among singleton births (125 per 1000) was higher than among multiple births (40 per 1000). The majority of deaths (77%) occurred in utero. Singleton perinatal mortality with abruption decreased from 173 per 1000 in 1987–1990 to 98 per 1000 in 2000–2005 (p < 0.001). In singleton births at <32 gestational weeks, overall perinatal mortality was high (345 per 1000) and was not increased by placental abruption. Prematurity, low birthweight, male fetal sex and maternal smoking were independent risk factors for placental abruption‐related perinatal mortality. Conclusions. Although mortality associated with placental abruption decreased during the study period, placental abruption still remains an important cause of perinatal mortality.

Etiology, clinical manifestations, and prediction of placental abruption

Placental abruption, defined as complete or partial detachment of the placenta before delivery, is one of the most devastating pregnancy complications. Bleeding and pain consist the classical symptoms of placental abruption but the clinical picture varies from asymptomatic, in which the diagnosis is made by inspection of the placenta at delivery, to massive abruption leading to fetal death and severe maternal morbidity. The diagnosis is always clinical. The etiology of placental abruption is not fully understood but impaired placentation, placental insufficiency, intrauterine hypoxia, and uteroplacental underperfusion are likely the key mechanisms causing abruption. Abruption results from a rupture of maternal decidual artery causing dissection of the decidual‐placental interface. Acute vasospasm of small vessels may precede abruption. The trophoplastic invasion in the spiral arteries and subsequent early vascularization may be defective. Moreover, placental abruption may also be a manifestation of an inflammatory process which could affect vascular bed. Despite heightened awareness, placental abruption still remains unpredictable and unpreventable. A clinically useful predictive test is needed to detect individuals at risk. Although several biomarkers have been evaluated, none has so far turned out to be useful.

Self-reported smoking habits and serum cotinine levels in women with placental abruption

Objective. Smoking is an important risk factor for placental abruption with strong dose‐dependency. Pregnant smokers often underreport tobacco use which can be objectively assessed by measuring serum cotinine levels. We examined the accuracy between self‐reported smoking habits and early pregnancy serum cotinine levels in women with or without placental abruption. Design. Retrospective case‐control study. Setting. University Hospital. Population. A total of 175 women with placental abruption and 370 control women. Methods. Serum samples collected during the first trimester were analyzed for serum cotinine levels. Cotinine concentration over 15 ng/ml was considered as the cutoff indicating active smoking. Smoking habits of the women and their partners were recorded at the same visit. Main outcome measure. Placental abruption. Results. Of the cases of women with placental abruption, 27.4% reported smoking compared with 14.3% of the controls (p < 0.001). Based on serum cotinine levels, 30.3% of the case women and 17.6% of the control women were considered smokers (p = 0.003). Serum cotinine levels among smokers were higher in the abruption group than in the control group (median 229.5 ng/ml (interquartile range 169.8–418.1) vs. 153.5 ng/ml (56.6–241.4), p = 0.002). Self‐reported number of cigarettes smoked daily correlated well with the cotinine levels (r = 0.68, p < 0.001). Of the women reporting as nonsmokers, approximately 7% were considered smokers based on cotinine testing. Conclusion. Pregnant women with subsequent placental abruption are heavier smokers than pregnant control women. Self‐reported smoking habits correlate well with serum cotinine levels in Finland. Therefore, self‐reported smoking can be considered as a risk marker for placental abruption.

Decreasing incidence of placental abruption in Finland during 1980–2005

Objective. To study the incidence trends of placental abruption. Design. Register‐based retrospective study. Setting. The Finnish Medical Birth Register and Hospital Discharge Register. Population. A total of 6231 placental abruption cases among 1 576 051 deliveries. Methods. Data on demographic and pregnancy and delivery associated outcomes were collected. Data on overall incidence and maternal age were available 1980–2005. Data on other variables were available 1987–2005. Main outcome measure. Placental abruption Results. The overall incidence of placental abruption was 395/100 000 (0.4%). The incidence decreased 31%, from 487/100 000 in 1980 to 337/100 000 in 2005 (p < 0.001). The incidence was lowest among women aged 20–24 years (305/100 000) and highest among women aged ≥45 years (1309/100 000). During 1987–2005 the incidence was lowest among women with one or two deliveries (353/100 000) and highest in nulliparous women (382/100 000) and in women with three or more deliveries (595/100 000). The incidence was nearly double (577/100 000) among smoking compared with non‐smoking women (341/100 000). The incidence was highest between gestational weeks 26 and 29. Among newborns weighing <1500 g the incidence was higher (5734/100 000) than among those weighing ≥2500 g (251/100 000). The incidence was higher in multiple (903/100 000) than in singleton pregnancies (374/100 000). Conclusion. The incidence of placental abruption decreased during 1980–2005. The incidence was highest among women aged 45 years or more, multiparous and smoking women, in multiple pregnancies and in women with low birthweight newborns.