Risk Of Abruption Research Articles

Acute and chronic respiratory diseases in pregnancy: Associations with placental abruption

Placental hypoxia has been speculated as the pathway leading to an association between maternal asthma during pregnancy and risk of abruption. The objective of this study is to examine the associations between acute and chronic respiratory diseases (hypoxic conditions) and abruption. A population-based retrospective cohort study was conducted to examine the associations between maternal respiratory disease (hypoxic conditions) and risk of abruption using the National Hospital Discharge Survey. The study cohort included women that delivered a singleton live birth or stillbirth (n = 37,190,632). International Classification of Diseases Ninth Revision, Clinical Modification (ICD-9-CM) codes were used to identify pregnancies hospitalized for: i) acute conditions (acute upper respiratory diseases, viral/bacterial pneumonia, and acute bronchitis/bronchiolitis) and ii) chronic conditions (chronic bronchitis and asthma) and abruption. All analyses were adjusted for maternal socioeconomic, demographic and behavioral characteristics. The rate of abruption among singleton pregnancies was 1 %. The overall rate for acute respiratory conditions was 2.1 per 1,000. Acute upper respiratory diseases (RR 3.21, 95% CI 3.04, 3.40) and viral/bacterial pneumonia (RR 2.16, 95% CI 1.94, 2.40) were associated with increased risk for abruption. The rate of chronic respiratory conditions was 8.9 per 1,000. Chronic bronchitis was strongly associated with abruption (RR 31.83, 95% CI 29.57, 34.42), but the association between asthma and abruption was weak (RR 1.03, 95% CI 1.00, 1.06). When we further stratified the data by maternal race, asthma was no longer a risk factor for abruption among whites (RR 0.89, 95% CI 0.85, 0.94) but remained a significant risk factor (RR 1.48, 95% CI 1.40, 1.57) among blacks. Pregnancies complicated by acute and chronic respiratory diseases are associated with increased risk for placental abruption. Our result suggests that a pregnancy complicated by chronic bronchitis is severe enough to warrant hospitalization.

In‐utero intervention for hypoplastic left heart syndrome — a perinatologist's perspective

.Today,whenHLHSisdiagnosedinthenewborn,or suspected by prenatal ultrasound studies, surgicalinterventions typically take one of two directions – eitherthe multistaged reconstruction pioneered by Norwood toenable single ventricle survival or cardiac transplantation.Compassionate care, although increasingly controversial,remains an option in some centers. Although increasingsurvival rates following both multi-staged surgery ortransplant are being reported, the nature of theseinterventions is such that these children remain at lifelongrisk for cardiac and neurologic morbidity.Consideration of HLHS as a candidate for

Impact of Maternal Age on Obstetric Outcome

To estimate the effect of maternal age on obstetric outcomes. A prospective database from a multicenter investigation of singletons, the FASTER trial, was studied. Subjects were divided into 3 age groups: 1) less than 35 years, 2) 35-39 years, and 3) 40 years and older. Multivariable logistic regression analysis was used to assess the effect of age on outcomes after adjusting for race, parity, body mass index, education, marital status, smoking, medical history, use of assisted conception, and patient's study site. A total of 36,056 women with complete data were available: 28,398 (79%) less than 35 years of age; 6,294 (17%) 35-39 years; and 1,364 (4%) 40 years and older. Increasing age was significantly associated with miscarriage (adjusted odds ratio [adjOR]2.0 and 2.4 for ages 35-39 years and age 40 years and older, respectively), chromosomal abnormalities (adjOR 4.0 and 9.9), congenital anomalies (adjOR 1.4 and 1.7), gestational diabetes (adjOR 1.8 and 2.4), placenta previa (adjOR 1.8 and 2.8), and cesarean delivery (adjOR 1.6 and 2.0). Patients aged 35-39 years were at increased risk for macrosomia (adjOR 1.4). Increased risk for abruption (adjOR 2.3), preterm delivery (adjOR 1.4), low birth weight (adjOR 1.6), and perinatal mortality (adjOR 2.2) was noted in women aged 40 years and older. Increasing maternal age is independently associated with specific adverse pregnancy outcomes. Increasing age is a continuum rather than a threshold effect.

Maternal and Neonatal Outcomes of Assaults During Pregnancy

To assess perinatal outcomes of women hospitalized for assault during pregnancy as a function of timing of delivery. A retrospective population-based study analyzing maternal discharge records linked to birth/death certificates in California from 1991 to 1999 was performed. International Classifications of Disease, Ninth Clinical Modification (ICD-9-CM) codes were used to identify injury types and outcomes. External causation codes identified assaults as the mechanism of the injuries. Injury Severity Scores were assessed. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated, and multivariate logistic regression was used for analysis of outcomes. A total of 2,070 women were hospitalized during pregnancy after sustaining an assault. Assaulted women were younger, multiparous, and with delayed prenatal care compared with unassaulted controls. Women delivering at the assault hospitalization had high rates of prematurity: 24%, OR 2.4 (95% CI 1.8-3.3), maternal death: 0.71%, OR 19 (95% CI 2.7-144.7), fetal death: 9.3%, OR 8 (95% CI 4.6-14.3), uterine rupture: 0.71%, OR 46 (95% CI 6.5-337.8), and other adverse outcomes compared with unassaulted women. Women discharged after an assault, delivering at a subsequent hospitalization, had increased risks of abruption: 2%, OR 1.8 (95% CI 1.3-2.5), hemorrhage: 3.2%, OR 1.8 (95% CI 1.4-2.5), prematurity: 15%, OR 1.3 (95% CI 1.2-1.5), and low birth weight: 13.4%, OR 1.7 (95% CI 1.5-1.9) at delivery. Women sustaining an assault during pregnancy experience both immediate (uterine rupture, increased fetal and maternal mortality) and long-term sequelae (prematurity and low birth weight infants), which have significant negative effects on pregnancy outcome. III.

Placental abruption in the United States, 1979 through 2001: Temporal trends and potential determinants

The purpose of this study was to evaluate temporal trends in abruption risk and to assess how much underlying changes in the clinical determinants may have affected these trends. We used the National Hospital Discharge Summary data (1979-2001), an annual survey of sampled non-federal, short stay, general, and specialty hospitals in the United States. Trends in abruption were assessed for the periods 1979 through 1981 and 1999 through 2001. Clinical determinants of abruption that were evaluated included hypertensive diseases, anemia, gestational diabetes mellitus, preterm labor, preterm premature rupture of membranes, chorioamnionitis, oligohydramnios, obstetric shock/trauma, uterine tumors, short umbilical cord, and velamentous cord insertion. Temporal trends in abruption were examined before and after adjustment for determinants through multivariable logistic regression. The rate of abruption increased 92% (95% CI, 88, 96) among black women between 1979-1981 (0.76%; n = 13,584 women) and 1999-2001 (1.43%; n = 18,960 women). Among white women, the rate increased by 15% (95% CI, 14,16) over the same period, from 0.82% (n = 66,186 women) in 1979-1981 to 0.94% (n = 59,284 women) in 1999-2001. The determinants that were associated with trends in abruption included anemia, gestational diabetes mellitus, preterm labor, short umbilical cord, and velamentous cord insertion, although their effects varied substantially by maternal race. The temporal increase in rates of abruption may reflect a true increase in risk or may be the result of improved diagnosis of both abruption and its determinants. Although the cause of abruption is still speculative, the trend is of concern and deserves scrutiny.

Preterm premature rupture of membranes, intrauterine infection, and oligohydramnios: risk factors for placental abruption.

To examine whether preterm premature rupture of membranes (PROM), intrauterine infection, and oligohydramnios are risk factors for placental abruption. Data for this retrospective cohort study were derived from the 1988 National Maternal and Infant Health Survey (N = 11,777). Association between abruption and these clinical risk factors was expressed as relative risk (RR) and 95% confidence interval (CI), with multivariate adjustment for potential confounders. The overall incidence of abruption was 0.87%. The risk of abruption was 3.58-fold higher (95% CI 1.74-7.39) among women with preterm PROM (2.29%) compared with women with intact membranes (0.86%). The rates of abruption among women with and without intrauterine infection were 4.81% and 0.83%, respectively (RR 9.71, 95% CI 3.23-29.17). However, oligohydramnios was not associated with abruption (1.46% compared with 0.87%; RR 2.09, 95% CI 0.92-5.31). Compared with women with intact membranes, the RR for abruption among preterm PROM and whose membranes were ruptured for 24-47 hours and 48 hours or more before delivery, respectively, were 2.37 (95% CI 0.99-9.09), and 9.87 (95% CI 3.57-27.82). When preterm PROM was accompanied by intrauterine infections, the RR for abruption was 9.03 (95% CI 2.80-29.15) compared with women with intact membranes and no infections. Similarly, preterm PROM accompanied by oligohydramnios conferred over a 7.17-fold risk (95% CI 1.35-38.10) for abruption compared with women with neither of these 2 conditions. Women presenting with preterm PROM are at increased risk of developing abruption, with the risk being higher either in the presence of intrauterine infections or oligohydramnios. Physicians managing patients with preterm PROM should be aware that these patients are at increased risk of developing abruption after 24 hours following preterm PROM.

Maternal thrombophilias are not associated with early pregnancy loss.

We investigated the association between inherited and acquired maternal thrombophilias and adverse pregnancy events. A cohort of 491 patients with a history of adverse pregnancy outcomes was evaluated for activated protein C resistance, factor V Leiden and prothrombin G20210A mutations, hyperhomocysteinemia, deficiencies of antithrombin, protein C and S and both anticardiolipin antibodies and lupus anticoagulants. The study had an 80% power to detect a 15% difference in the prevalence of thrombophilia for 1(st) trimester loss. In our high-risk cohort the presence of 1 maternal thrombophilia or more than one thrombophilia were found to be protective of recurrent losses at < 10 weeks (1 thrombophilia: OR: 0.55, 95% CI: 0.33-0.92; > 1 thrombophilia: OR: 0.48, 95%CI:0.29-0.78). In contrast, the presence of maternal thrombophilia(s) was modestly associated with an increased risk of losses > 10 weeks (1 thrombophilia: OR:1.76, 95%CI: 1.05-2.94, >1 thrombophilia: OR:1.66, 95%CI:1.03-2.68). Women who experienced only euploid losses were not more likely to have an identified thrombophilia than women who experienced only aneuploid losses (OR 1.03; 0.38-2.75). The presence of maternal thrombophilia was associated with an increased risk of fetal loss after 14 weeks, fetal growth restriction, abruption and preeclampsia. There was a significant "dose-dependent" increase in the risk of abruption (OR:3.60, 95%CI: 1.43-9.09) and preeclampsia (OR:3.21, 95%CI:1.20-8.58). In conclusion, these data indicate maternal thrombophilias are not associated with pregnancy wastage prior to 10 weeks of gestation.

Birth weight discordancy and adverse perinatal outcomes among twin gestations in the United States: The effect of placental abruption

Objective: We evaluated whether the relationship between birth weight discordancy of twins and stillbirth, neonatal deaths, and preterm births was modified by the presence of abruption. Study Design: We used the 1995 to 1997 matched multiple birth file for United States twin births (n = 269,287). Birth weight discordancy was defined as the ratio of the difference in birth weight of the heavier from the lighter twin to that of the heavier twin and was categorized as <5%, 5% to 9%, 10% to 14%, 15% to 19%, 20% to 29%, 30% to 39%, and ≥40%. We evaluated the risks of stillbirth (≥20 weeks of gestation), neonatal deaths (within 28 days after birth), and preterm birth (< 32 weeks) in the presence and absence of abruption. Associations between birth weight discordancy and these perinatal outcomes were expressed as adjusted relative risks and were derived from multivariable logistic regression models, based on the method of generalized estimating equations. Risk of these outcomes were derived for each stratum of birth weight discordancy and abruption status, with the <5% birth weight discordancy, nonabruption status labeled as the reference group. All analyses were performed separately for same and different sex twins. Results: A birth weight discordancy of ≥20% among same sex (adjusted relative risk, 1.2; 95% CI, 1.1, 1.4), and ≥40% among different sex twins (relative risk, 2.2; 95% CI, 1.7, 2.8) conferred increased risk for abruption. Among nonabruption births, a birth weight discordancy of ≥15% among same sex and ≥30% among different sex twins increased the risk of stillbirths, neonatal deaths, and preterm births. Among abruption births, however, the risks were increased even in the lowest birth weight discordancy category (<5%). The relative risks of stillbirths and neonatal deaths among abruption births were significantly higher for each birth weight discordancy group, both for same and different sex twins, compared with the reference group. The association between birth weight discordancy and preterm birth was not modified by either the presence or absence of abruption. Conclusion: Birth weight discordancy of ≥15% for same sex and ≥30% for different sex confer greatest risk of adverse perinatal outcomes in the absence of abruption. In the presence of placental abruption, these risks are further compounded. The results underscore the need for careful monitoring of twin pregnancies. (Am J Obstet Gynecol 2003;188:954-60.)

Smoking, sex of the offspring, and risk of placental abruption, placenta previa, and preeclampsia: a population-based cohort study.

: Placental abruption, placenta previa, and preeclampsia are serious pregnancy complications with an increased risk of perinatal death. Smoking during pregnancy is associated with increased risk of abruption and placenta previa, and it reduces the risk of preeclampsia. We examined the association between mothers' smoking habits during pregnancy, taking the sex of the offspring into consideration, and the risk and prognosis of placental abruption, placenta previa, and preeclampsia : We conducted the study in the County of North Jutland, Denmark. Using the 10-digit personal identification number given to every Danish citizen at birth, we linked data from the Danish Medical Birth Registry, including information on mother and child, to data from the Pharmaco-Epidemiological Prescription Database with data on all reimbursed prescriptions to use selected drugs as a proxy measure for some maternal diseases, and data from the Regional Hospital Discharge Registry, including the discharge diagnoses. Among 47,932 singleton births we included only births for which we had information about the mothers' smoking habits, leaving 46,313 births for analysis. : Smoking was associated with the risk of placental abruption (OR=1.99 (95% CI 1.72-2.30)) and placenta previa (OR=1.88 (95% CI 1.15-3.07)). Smoking was inversely associated with the risk of preeclampsia (OR=0.55 (95% CI 0.48-0.62)). After stratification for the sex of the offspring the risk estimate of smoking as risk factor for placenta previa decreased for male fetuses (OR=1.63 (95% CI 0.75-3.51)) and increased for female fetuses (OR=4.82 (95% CI 1.69-13.75)). : Female fetuses are more vulnerable than male to the negative effect of maternal smoking on placenta previa.

Risk Factor Profiles of Placental Abruption in First and Second Pregnancies: Heterogeneous Etiologies

The objective of this study was to identify risk factors for placental abruption in first and second pregnancies and to compare the risk-factor profiles for evidence of etiologic heterogeneity. A prospective cohort design was used. The study took place at university-based medical centers that participated in the U.S. Collaborative Perinatal Project (1959–1965). A total of 10,774 first pregnancies only and 6529 first and second pregnancies of women were enrolled in the study. Participation rate was 96%. All pregnancies were selected at some centers, whereas other centers used either random or systematic sampling. The main outcome measure was placental abruptions in first and second pregnancies. The placental abruption rate was 1.7% ( n = 182) for first and 2.2% ( n = 143) for second pregnancies. Prior abruption increased risk in second pregnancies significantly (odds ratio [OR] = 3.2, 95% confidence interval [CI]: 1.7–5.8) after adjusting for other risk factors. Placental infarcts and smoking duration were associated with an increased risk for abruption in second but not first pregnancies. Effect of placental infarcts was modified by gestational age with strongest risk for abruption at shortest gestations. For each year of smoking prior to pregnancy, risk of abruption increased 40% (OR = 1.4, 95% CI 1.0–1.8). Etiologies of placental abruption for first and second pregnancies were different, indicating heterogeneity in their risk-factor profiles. Future research would best consider abruption as a heterogeneous complication to further knowledge of its etiology.

INCIDENCE OF PLACENTAL ABRUPTION IN RELATION TO CIGARETTE SMOKING AND HYPERTENSIVE DISORDERS DURING PREGNANCY

In Brief Objective To systematically review the literature and summarize the relationship between cigarette smoking and placental abruption, and to evaluate the joint influences of smoking and hypertensive disorders (chronic hypertension and preeclampsia) on the subsequent development of abruption. Data Sources We reviewed studies identified through a MEDLINE literature search between 1966 and 1997 and through studies cited in the references of published reports. Methods of Study Selection A total of 13 observational (seven case-control and six cohort) studies were identified which included a total of 1,358,083 pregnancies. We excluded case reports on placental abruption, and restricted the literature search to studies published in English. A meta-analysis was performed by computing pooled odds ratios based on random-effects models describing the association between placental abruption, smoking, and hypertensive disorders. Potential sources of heterogeneity among these studies were explored in detail. Tabulation, Integration, and Results The overall incidence of placental abruption was 0.64% (8724 of 1,358,623). Smoking was associated with a 90% increase in the risk of placental abruption (odds ratio [OR] 1.9, 95% confidence interval [CI] 1.8, 2.0). This pattern was consistent by study design (case-control compared with cohort studies) and smoking prevalence (low compared with high prevalence, defined as less than 30% compared with 30% or more, respectively). However, the association was significantly (P < .001) stronger among the seven studies conducted outside the United States (OR 2.1, 95% CI 2.0, 2.2), compared with the six studies conducted in the United States (OR 1.6, 95% CI 1.5, 1.8). Pooled population attributable risk percentage for each stratum ranged between 15% and 25%, implying that 15–25% of placental abruption episodes are attributable to cigarette smoking. Data on the dose-response relationship between number of cigarettes smoked per day and the risk of abruption indicate that the OR increased with increasing number of cigarettes smoked. Furthermore, a meta-analysis of the joint effects of smoking and hypertension during pregnancy on the development of abruption identified two published studies, including 102,609 pregnancies. In the presence of smoking, the risk of abruption was further increased due to chronic hypertension, mild or severe preeclampsia, or chronic hypertension with superimposed preeclampsia. Conclusion Our meta-analyses showed an increased risk for placental abruption in relation to both cigarette smoking and hypertensive disorders during pregnancy. Because cigarette smoking is a modifiable risk factor, and hypertensive disorders are potentially treatable if diagnosed early in pregnancy, patient education, smoking cessation programs, and early prenatal care may be important factors in the prevention of placental abruption. A meta-analysis comprising 1.4 million pregnancies indicates that cigarette smoking during pregnancy is associated with a two-fold increase in the risk for placental abruption.

Influence of hypertensive disorders and cigarette smoking on placental abruption and uterine bleeding during pregnancy.

To assess the influence of hypertensive disorders in pregnancy on the subsequent risk of placental abruption and uterine bleeding of unknown aetiology, and to examine the combined effects of hypertensive disorders and cigarette smoking during pregnancy on the risk of uteroplacental bleeding disorders. Retrospective cohort study. Data for this study were derived from the Nova Scotia Atlee Perinatal database, Canada, comprising of women who were delivered in the province between 1980 and 1993. 120,666 pregnancies resulting in singleton births, of which 13,360 pregnancies were complicated by pre-eclampsia and/or chronic hypertension. Risks and relative risks of placental abruption and uterine bleeding of unknown aetiology in pregnancies complicated by chronic hypertension, mild and severe pre-eclampsia, and chronic hypertension with superimposed pre-eclampsia, each compared with normotensive patients. Adjusted relative risks were obtained through the fit of multivariable logistic regression models based on the method of generalised estimating equations. Chronically hypertensive women had no increased risk of abruption (RR 1.4; 95% CI 0.5-3.6), while women whose pregnancies were complicated by severe pre-eclampsia (RR 3.8; 95% CI 2.1-6.9), and chronic hypertension with superimposed pre-eclampsia (RR 2.8; 95% CI 1.2-6.3) showed strong associations with placental abruption. However, none of the hypertensive disorders were associated with uterine bleeding of unknown aetiology. The association between placental abruption and hypertensive disorders varied by parity. Parous women with chronic hypertension and superimposed pre-eclampsia were at greater risk of placental abruption (aRR 3.8; 95% CI 1.9-7.8) than nulliparous women with chronic hypertension and superimposed pre-eclampsia (aRR 1.6; 95% CI 0.5-4.9). The joint effects of smoking and hypertension had a greater effect on the risk of placental abruption than would have been expected based on their individual effects. The pattern of association between placental abruption and hypertension varied in relation to the specific type of hypertensive disorder. However, uterine bleeding of unknown aetiology was not associated with hypertension. Findings from this study suggest that placental abruption and uterine bleeding of unknown origin are aetiologically distinct obstetric complications with respect to hypertensive disorders during pregnancy.

Risk Factors for Abruptio Placentae

The authors studied the relation of sociodemographic, medical, and life-style factors and abruptio placentae in a large cross-sectional data base. The 143 cases of abruption identified in the Delivery Interview Program, conducted in Boston from 1977 to 1980, were compared with 1,257 randomly selected controls. The authors used multiple logistic regression techniques to derive maximum likelihood estimates of the adjusted odds ratios and 95% confidence intervals as measures of the association between exposure factors and abruption. A history of chronic hypertension was associated with a threefold increase in risk (odds ratio (OR) = 3.1, 95% confidence interval (Cl) 1.1-8.4), but pregnancy-induced hypertension was not associated with abruption. Excess risk was associated with advanced maternal age (OR = 2.3, 95% Cl 1.3-3.9), low prepregnancy body mass index (OR = 2.3, 95% Cl 1.3-4.1), a history of prior stillbirth (OR = 3.5, 95% Cl 1.8-7.0), and at least weekly use of marijuana during pregnancy (OR = 2.8, 95% Cl 1.2-6.6). Overall, the association with cigarette smoking during pregnancy was of only borderline significance (OR = 1.5, 95% Cl 1.0-2.2), although there appeared to be a dose-response relation between the number of cigarettes smoked and risk of abruption.

CHRONIC HYPERTENSION, CIGARETTE SMOKING, AND ABRUPTIO PLACENTAE

We investigated the importance of maternal hypertension and cigarette smoking, and their interaction, as risk factors for abruptio placentae, using Massachusetts birth certificate data for 1987-1988. We used multiple logistic regression procedures to model data from 943 abruptio placentae cases and 10,648 randomly selected births. Risk of abruption was associated with a history of chronic hypertension (adjusted OR = 2.3, 95% CI: 1.5-3.5) and cigarette smoking during pregnancy (adjusted OR = 1.7, 95% CI: 1.5-2.0). There was also evidence of interaction between chronic hypertension and cigarette smoking. The hypoxemia that results from exposure to cigarette smoke and the alterations in uterine blood flow that result from hypertension may lead to placental lesions that cause abruption.

Empirical estimates of beta when investors face estimation risk : Peter M. Clarkson

&#x0D; &#x0D; &#x0D; The authors examine empirical implications of models of differential information that formalize the following intuition: securities for which there is relatively little information are perceived as relatively more risky because of the greater uncertainty surrounding the exact parameters of their return distributions. The implication that beta risk for low information firms should decline as information increases is confirmed with several data sets. The authors find such a decline over the first several periods subsequent to initial public offerings and initial listings. There is also an abrupt risk decline at the first annual earnings announcement. Journal ofFinance, Vol. 45, No. 2 (June 1990), pp. 431-453. (Reprinted with permission of the Journal ofEconomic Literature.)&#x0D; &#x0D; &#x0D;

Empirical Estimates of Beta When Investors Face Estimation Risk

ABSTRACTWe examine empirical implications of models of differential information that formalize the following intuition: securities for which there is relatively little information are perceived as relatively more risky because of the greater uncertainty surrounding the exact parameters of their return distributions. The implication that beta risk for low information firms should decline as information increases is confirmed with several data sets. We find such a decline over the first several periods subsequent to initial public offerings and initial listings. There is also an abrupt risk decline at the first annual earnings announcement.

Empirical Estimates of Beta When Investors Face Estimation Risk

We examine empirical implications of models of differential information that formalize the following intuition: securities for which there is relatively little information are perceived as relatively more risky because of the greater uncertainty surrounding the exact parameters of their return distributions. The implication that beta risk for low information firms should decline as information increases is confirmed with several data sets. We find such a decline over the first several periods subsequent to initial public offerings and initial listings. There is also an abrupt risk decline at the first annual earnings announcement.