Subsequent risk of cancer among women with a history of placental abruption.

BACKGROUND: Placentation is characterized by extensive cell proliferation and neovascularization, which is similar to the processes observed in the development of cancer. Nonetheless, little is known about the relation between abnormal placentation, such as placental abruption, and cancer. MATERIAL AND METHODS: Data on women with placental abruption in a singleton pregnancy between 1971 and 2005 (n = 7804) were collected from the Finnish Hospital Discharge Registry and the Finnish Medical Birth Registry. The cohort was then linked with the Finnish Cancer Registry records until the end of 2013. Standardized incidence ratios (SIRs) were calculated for different cancers by dividing the observed numbers of cancers by those expected. The expected numbers were based on national cancer incidence rates. RESULTS: During follow-up, 597 cancers were found among women with a history of placental abruption. The overall risk of cancer was not increased (SIR 0.95, 95% CI 0.88-1.02). However, the history of placental abruption was associated with an increased risk of lung cancer (SIR 1.51, 95% CI 1.05-2.10) and thyroid cancer (SIR 1.47, 95% CI 1.04-2.02). A decreased risk was found for breast cancer (SIR 0.85, 95% CI 0.75-0.96). The risk of rectal cancer was also decreased, although these numbers were small (SIR 0.49, 95% CI 0.20-1.01). CONCLUSIONS: Overall, the risk of lung cancer was increased, and the risk of breast cancer decreased, in women with a history of placental abruption. These observations can be explained to some extent by risk factors or risk markers for placental abruption. The increased risk of thyroid cancer may be explained by surveillance bias.

Placental Abruption and Child Mortality.

BACKGROUND AND OBJECTIVES: Placental abruption causes asphyxia and leads to high perinatal mortality. Our objective was to study the overall mortality and causes of death among children born after placental abruption. METHODS: Data on children born from singleton pregnancies complicated by placental abruption between 1987 and 2005 were collected from the Finnish Medical Birth Register, the Hospital Discharge Register, and the Cause-of-Death Register. A reference group consisted of children born from pregnancies without placental abruption. After excluding stillbirths, the final study sample comprised 3888 children born after placental abruption (index children) and 12 530 referent children. The main outcome measure was overall mortality. RESULTS: By the end of 2013, there were 280 deaths among the index children and 107 deaths among the referent children. Compared with the referent children, the overall mortality among the index children was significantly increased (hazard ratio: 8.70; 95% confidence interval 6.96-10.90). During the neonatal period (0-27 days) the mortality was nearly 15-fold (14.8; 10.9-20.0), birth-related asphyxia being the leading cause of death (108; 34-341). The mortality remained high during days 28 to 365 (10.3; 4.83-21.8) and beyond 365 days (1.70; 1.03-2.79). Furthermore, the overall mortality was increased among the index children born at 32 to 36 + 6 gestational weeks (2.77; 1.54-4.98) and at ≥37 weeks (4.98; 3.54-6.99) and among children with a birth weight of 2500 g or more (5.94; 4.33-8.14). CONCLUSIONS: The impact of abruption on offspring mortality extends far beyond the perinatal period. This is mainly due to birth-related asphyxia and prematurity-related consequences.

Mortality and causes of death among women with a history of placental abruption.

INTRODUCTION: Women with a history of placental abruption have an increased later morbidity, but not much is known of the later mortality. MATERIAL AND METHODS: Data on women with placental abruption (index cohort) between 1969 and 2005 (n = 7805) were collected from the Finnish Hospital Discharge Register and the Finnish Medical Birth Register. A matched reference cohort consisted of women without placental abruption (n = 23 523). The causes of death were retrieved from the Cause-of-Death Register. Cause-specific mortality was compared by hazard ratios (HR). Standardized mortality ratios were calculated to compare both cohorts with the general female population. The main outcome measure was subsequent mortality. RESULTS: By the end of 2013 there were 395 deaths in the index cohort and 863 deaths in the reference cohort. The overall mortality was increased in the index cohort compared with the reference cohort [HR 1.39, 95% confidence interval (CI) 1.24-1.57]. The index cohort had an increased risk of death from respiratory tract malignancies (HR 1.72, 95% CI 1.05-2.82), alcohol-related causes (HR 1.84, 95% CI 1.25-2.72), and external causes (HR 1.63, 95% CI 1.19-2.22), especially suicide (HR 1.71, 95% CI 1.07-2.74). The mortality from cardiovascular diseases did not differ. The standardized mortality ratio was increased in the index cohort compared with the general Finnish female population (HR 1.13, 95% CI 1.02-1.24), especially for respiratory tract malignancies (HR 1.79, 95% CI 1.16-2.64). The index cohort women tended to die younger than referent women (p < 0.001). CONCLUSIONS: Overall mortality among women with a history of placental abruption is increased. These women tend to die younger than referent women do.

Increased prevalence of major congenital anomalies in births with placental abruption.

OBJECTIVE: To examine the association between major congenital anomalies and placental abruption. METHODS: A register-based retrospective case-control study was carried out from 1987 to 2005. Data on baseline characteristics and birth outcomes were collected from three Finnish national health registers: the Medical Birth Register, National Hospital Discharge Register, and Register of Congenital Malformations. The study population consisted of 4,190 women with singleton birth and placental abruption. Three control women without placental abruption were selected for each case, matched by maternal age, parity, year of birth, and hospital district. The main outcome measure of the study was a major congenital anomaly associated with placental abruption. RESULTS: In total, 261 (prevalence 623/10,000) births with placental abruption and 415 (prevalence 330/10,000) control births had major congenital anomalies (odds ratio [OR] 1.92, 95% confidence interval [CI] 1.6-2.52). The association was strongest among births with growth restriction and prematurity. Adjusted analysis revealed a significant association with central nervous system anomalies (OR 2.33, 95% CI 1.29-4.23), anomalies of the eyes and ears (OR 1.82, 95% CI 1.08-3.09), cardiovascular anomalies (OR 1.78, 95% CI 1.34-2.37), respiratory anomalies (OR 3.51, 95% CI 1.56-7.90), gastrointestinal anomalies (OR 3.81, 95% CI 2.27-6.41), genitourinary anomalies (OR 2.55, 95% CI 1.73- 3.74), musculoskeletal anomalies (OR 1.67, 95% CI 1.24-2.24), and anomalies of integument (OR 3.29, 95% CI 1.20-8.98) in births complicated by placental abruption. CONCLUSIONS: Major congenital anomalies are twice as common among neonates born from pregnancies complicated by placental abruption compared with control pregnancies without abruption. This observation applies to several organ systems. LEVEL OF EVIDENCE: II.

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.