Association of caesarean delivery for first birth with placenta praevia and placental abruption in second pregnancy

Objective  To quantify the risk of placenta praevia and placental abruption in singleton, second pregnancies after a caesarean delivery of the first pregnancy.
Design  Retrospective cohort study.
Setting  Linked birth and infant mortality database of the USA between 1995 and 2000.
Population  A total of 5 146 742 singleton second pregnancies were available for the final analysis after excluding missing information.
Methods  Multiple logistic regressions were used to describe the relationship between caesarean section at first birth and placenta praevia and placental abruption in second-birth singletons.
Main outcome measures  Placenta praevia and placental abruption.
Results  Placenta praevia was recorded in 4.4 per 1000 second-birth singletons whose first births delivered by caesarean section and 2.7 per 1000 second-birth singletons whose first births delivered vaginally. About 6.8 per 1000 births were complicated with placental abruption in second-birth singletons whose first births delivered by caesarean section and 4.8 per 1000 birth in second-birth singletons whose first births delivered vaginally. The adjusted odds ratio (95% CIs) of previous caesarean section for placenta praevia in following second pregnancies was 1.47 (1.41, 1.52) after controlling for maternal age, race, education, marital status, maternal drinking and smoking during pregnancy, adequacy of prenatal care, and fetal gender. The corresponding figure for placental abruption was 1.40 (1.36, 1.45).
Conclusion  Caesarean section for first live birth is associated with a 47% increased risk of placenta praevia and 40% increased risk of placental abruption in second pregnancy with a singleton.     

The effect on the likelihood of further pregnancy of placental abruption and the rate of its recurrence

Objective To assess the effect of having a placental abruption on 1. the probability of having further pregnancies, and 2. the rate of recurrence in such pregnancies.
Design A cohort study based on the Medical Birth Registry of Norway.
Results From 1967 to 1989, placental abruption occurred in 218/4951 subsequent deliveries after a placental abruption index case. After placental abruption with perinatal survival in the first delivery 59% of women had a further delivery, compared with 71% who did not have placental abruption at delivery. After a perinatal loss corresponding rates were 83% and 85%, respectively. Odds ratios of recurrence of abruption, crude and adjusted for maternal age, birth order and time period were 7.1 and 6.4, respectively. No secular trends were found. Caesarean section rates increased and were higher in pregnancies with recurrent placental abruption and in subsequent pregnancies without placental abruption than in the total birth population.
Conclusions Women who have placental abruption are less likely than other women to have another pregnancy. For women who do have subsequent pregnancies placental abruption occurs significantly more frequently.     

Incidence,obstetric risk factors and pregnancy outcome of preterm placental abruption: a retrospective analysis

Objective: To determine obstetric risk factors for the occurrence of preterm placental abruption and to investigate its subsequent perinatal outcome. Study design: A retrospective comparison of all singleton preterm deliveries complicated with placental abruption, between the years 1990-1998, to all singleton preterm deliveries without placental abruption, in the Soroka University Medical Center. Results: Placental abruption complicated 300 (5.1%) of all preterm deliveries (n = 5934). A back-step multivariable analysis found the following factors to be independently correlated with the occurrence of preterm placental abruption: grandmultiparity (more than five deliveries), early gestational age, severe pregnancy-induced hypertension, previous second-trimester bleeding and non-vertex presentation. These pregnancies had a significantly lower rate of preterm premature rupture of membranes than preterm pregnancies without placental abruption. Pregnancies complicated with preterm placental abruption had significantly higher rates of cord prolapse, non-reassuring fetal heart rate patterns, congenital malformations, Cesarean deliveries, perinatal mortality, Apgar scores lower than 7 at 5 min, postpartum anemia and delayed discharge from the hospital than did preterm deliveries without placental abruption. In order to assess whether the increased risk for perinatal mortality was due to the placental abruption, or due to its significant association with other risk factors, a multivariable analysis was constructed with perinatal mortality as the outcome variable. Placental abruption (OR 3.0, 95% CI 2.1-4.1) as well as cord prolapse, previous perinatal death, low birth weight and congenital malformations were found to be independent risk factors for perinatal mortality. Conclusion: Preterm placental abruption is an unpredictable severe complication associated with significant perinatal morbidity and mortality. Factors found to be independently associated with placental abruption were grandmultiparity, severe pregnancy-induced hypertension, malpresentation, earlier gestational age and a history of second-trimester vaginal bleeding.     

Factor V Leiden in pregnancies complicated by placental abruption

Objective Recent studies suggest an increased prevalence of obstetric complications in female carriers of hereditary or acquired thrombophilias. The aim of the study was to determine if carriership of the factor V (FV) Leiden mutation (activated protein C [APC] resistance) is higher in women who have had of placental abruption during pregnancy.
Design A retrospective case–control study.
Setting University Hospital MAS, Malmö, Sweden.
Methods A comparison of 102 women with placental abruption with 2371 prospectively collected controls. Carriership of FV Leiden was determined and the women were interviewed.
Main outcome measures Proportion of FV Leiden carriership, first degree heritage of thrombosis and previous placental abruption in cases and controls.
Results Carriage of FV Leiden was found in 15.7% of women who have had placental abruption as compared with 10.8% of controls (   P = 0.12, odds ratio [OR] = 1.5, 95% confidence interval [CI] = 0.9–2.7  ). Around 20% of women with placental abruption reported first degree heritage for venous thrombosis, as compared with 6.7% of controls (   P ≤ 0.001  ).
Conclusions FV Leiden carriership was not significantly different in women with placental abruption. However, there was an increased prevalence of first degree heritage for venous thrombosis in women with placental abruption, indicating a higher prevalence of thrombophilia among women with placental abruption.     

Perinatal mortality associated with abruptio placenta in singletons and multiples

OBJECTIVE: This study was undertaken to investigate the association among plurality (number of fetuses per pregnancy), abruptio placenta, and perinatal mortality. STUDY DESIGN: A retrospective cohort study on 15,051,872 singletons, 413,619 twins, and 22,585 triplets delivered in the United States between 1995 and 1998 was conducted. We compared the occurrence of perinatal death between pregnancies complicated by abruptio placenta and those without with the use of adjusted odds ratios. The generalized estimating equations framework was applied to adjust for intracluster correlations among multiples. RESULTS: Placental abruption occurred among 93,968 singletons (6.2 per 1000), 5051 twin (12.2 per 1000), and 353 triplet (15.6 per 1000) gestations ( P for trend<.0001). Placental abruption was associated with significant risk of mortality irrespective of the plurality subtype. Perinatal mortality was greatest among singletons (adjusted odds ratio [95% CI]=14.3[13.2-15.4]), followed by twins (4.4[3.9-4.9]) and least among triplets (3.0[2.0-4.6]) ( P for trend<.0001). CONCLUSION: As plurality increases from 1 to 3, the risk of placental abruption rises, whereas the risk of abruptio-associated perinatal mortality declines.     

Incidence of placental abruption in relation to cigarette smoking and hypertensive disorders during pregnancy: a meta-analysis of observational studies

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.     

Placental abruption,offspring sex,and birth outcomes in a large cohort of mothers

Objective.?To investigate stillbirth, neonatal, and perinatal death outcomes in pregnancies complicated by placental abruption, according to fetal sex.

Methods.?We utilized maternally linked cohort data files of singleton live births to mothers diagnosed with placental abruption during the period 1989 through 2005 (n?=?10,014). Logistic regression models were employed to generate adjusted odd ratios and their 95% confidence intervals. Male babies served as the referent category.

Results.?The sex ratio at birth was 1.18. The overall prevalence of stillbirth, neonatal mortality, and perinatal mortality was 7.2%, 4.5%, and 11.8%, respectively. Placental abruption was less likely to occur in mothers carrying female pregnancies than mothers of male infants (adjusted odds ratio [95% confidence interval]?=?0.89 [0.86–0.93]). There were no significant sex differences with regards to stillbirth, neonatal mortality, and perinatal mortality. Similar findings were observed for preterm and term infants.

Conclusions.?Although a preponderance of male infants was discernable among mothers with placental abruption, no sex difference in fetal survival was observed among the offspring of the mothers affected by 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.     

Maternal pre-gravid body weight and risk for placental abruption among twin pregnancies

Abstract

Objectives.?Placental abruption is a major cause of fetal and neonatal death and has been reported more frequently in twin pregnancies than among singleton gestations. The purpose of this article is to investigate the role of maternal pre-gravid body mass index (BMI) on the risk for placental abruption among twin pregnancies.

Methods.?We used the Missouri maternally linked cohort files (years 1989–1997) consisting of twin live births (gestational age 20–44 weeks). Maternal pre-gravid weight was classified based on the following BMI-based categories: normal (18.5–24.9), underweight (<18.5), overweight (25–29.9), and obese (>30). We used logistic regression for generated adjusted odds ratios with correction for the presence of intra-cluster correlation using generalized estimating equations.

Results.?Overall, 261 cases of placental abruption were registered over the entire study period, yielding a placental abruption rate of 14.9/1000. The frequency of placental abruption correlated negatively with maternal BMI in a dose–effect pattern: underweight (19.3/1000); normal weight (16.1/1000); overweight (13.9/1000); and obese (9.5/1000) mothers (p for trend?<?0.01). After adjusting for confounders, the likelihood of placental abruption was still lower in obese women (OR?=?0.58; 95% CI?=?0.38–0.87). By contrast, women who were underweight had a 20–30% greater likelihood for placental abruption when compared with normal weight mothers, although these findings were statistically not significant.

Conclusions.?There is an inverse relationship between pre-gravid maternal BMI and placental abruption. The mechanism by which obesity impacts the likelihood of placental abruption in twin pregnancies requires further study.     

Pregnancy following placental abruption

The aim of the present study by a retrospective chart review was to examine the recurrence rate after placental abruption. Between 1985 and 1998, 81 patients had a placental abruption. We had 2-year follow-up information about 31 patients and 27 of them had a total of 34 subsequent pregnancies. Recurrent placental abruption was observed in 6 pregnancies in 6 patients (6/27, 22.2%). Of the 6 recurrent placental abruptions, the gestational age was 1–3 weeks earlier than that of previous abruption in 4 patients. One patient delivered a healthy baby after her first abruption and then experienced a second abruption. We conclude that careful management is needed after 30 weeks in pregnant women with a previous history of placental abruption. Received: 24 April 2001 / Accepted: 2 July 2001 Acknowledgments We thank medical staff of the Department of Obstetrics and Gynecology in Handa City Hospital, Nagoya Daini Red Cross Hospital, and Toyohashi Municipal Hospital for their support.     

Risk factors for placental abruption in a socio-economically disadvantaged region.

OBJECTIVE: This study was undertaken in order to determine the risk factors for pregnancies complicated by placental abruption in a socio-economically disadvantaged region in metropolitan Adelaide. METHODS: This was a retrospective case-control study including all singleton pregnancies resulting in placental abruption between 2001 and 2005. RESULTS: The overall incidence of placental abruption was 1.0%; the overall perinatal mortality among the births with abruption was 13%. Univariate analyses showed the following significant risk factors for placental abruption: preterm pre-labor rupture of the membranes (PRE-PROM; odds ratio (OR) 4.79, 95% confidence interval (CI) 1.52-15.08), non-compliance with antenatal care (OR 2.93, 95% CI 1.06-8.90), severe intrauterine growth restriction (IUGR), and elevated homocysteine levels (OR 45.55, 95% CI 7.05-458.93). Severe IUGR was significantly more common in the abruption group compared with the control group (p = 0.032). In the multivariate analysis, PRE-PROM remained a significant independent risk factor for placental abruption. Marijuana use, domestic violence, and mental health problems were more common (borderline significance) in the abruption group. Smoking and preeclampsia were not found to be associated with placental abruption in this study. CONCLUSIONS: In this high-risk population, PRE-PROM and elevated homocysteine levels appear to represent the major risk factors for placental abruption.     

Risk factors for placental abruption in a socio-economically disadvantaged region

Objective. This study was undertaken in order to determine the risk factors for pregnancies complicated by placental abruption in a socio-economically disadvantaged region in metropolitan Adelaide.

Methods. This was a retrospective case–control study including all singleton pregnancies resulting in placental abruption between 2001 and 2005.

Results. The overall incidence of placental abruption was 1.0%; the overall perinatal mortality among the births with abruption was 13%. Univariate analyses showed the following significant risk factors for placental abruption: preterm pre-labor rupture of the membranes (PRE-PROM; odds ratio (OR) 4.79, 95% confidence interval (CI) 1.52–15.08), non-compliance with antenatal care (OR 2.93, 95% CI 1.06–8.90), severe intrauterine growth restriction (IUGR), and elevated homocysteine levels (OR 45.55, 95% CI 7.05–458.93). Severe IUGR was significantly more common in the abruption group compared with the control group (p = 0.032). In the multivariate analysis, PRE-PROM remained a significant independent risk factor for placental abruption. Marijuana use, domestic violence, and mental health problems were more common (borderline significance) in the abruption group. Smoking and preeclampsia were not found to be associated with placental abruption in this study.

Conclusions. In this high-risk population, PRE-PROM and elevated homocysteine levels appear to represent the major risk factors for placental abruption.     

Recurrence of ischemic placental disease

OBJECTIVE: To test the hypothesis that the presence of preeclampsia, small for gestational age (SGA)-birth, and placental abruption in the first pregnancy confers increased risk in the second pregnancy. METHODS: A retrospective cohort study entailing a case-crossover analysis was performed based on women who had two consecutive singleton live births (n=154,810) between 1989 and 1997 in Missouri. Small for gestational age was defined as infants with birth weight below the 10th centile for gestational age. Risk and recurrence of ischemic placental disease was assessed from fitting logistic regression models after adjusting for several confounders. RESULTS: Preeclampsia in the first pregnancy was associated with significantly increased risk of preeclampsia (odds ratio 7.03, 95% confidence interval 6.51, 7.59), SGA (odds ratio 1.16, 95% confidence interval 1.06, 1.27), and placental abruption (odds ratio 1.90, 95% confidence interval 1.51, 2.38) in the second pregnancy. Similarly, women with SGA and abruption in the first pregnancy were associated with increased risks of all other conditions in the second pregnancy. CONCLUSION: Women with preeclampsia, SGA, and placental abruption in their first pregnancy--conditions that constitute ischemic placental disease--are at substantially increased risk of recurrence of any or all these conditions in their second pregnancy. Although causes of these conditions remain largely speculative, these entities may manifest through a common pathway of ischemic placental disease with significant risk of recurrence.     

Placental abruption: critical analysis of risk factors and perinatal outcomes

Objective.?To investigate risk factors and pregnancy outcome of patients with placental abruption.

Methods.?A population-based study comparing all pregnancies of women with and without placental abruption was conducted. Stratified analysis using multiple logistic regression models was performed to control for confounders.

Results.?During the study period there were 185,476 deliveries, of which 0.7% (1365) occurred in patients with placental abruption. The incidence of placental abruption increased between the years 1998 to 2006 from 0.6 to 0.8%. Placental abruption was more common at earlier gestational age. The following conditions were significantly associated with placental abruption, using a multivariable analysis with backward elimination: hypertensive disorders, prior cesarean section, maternal age, and gestational age. Placental abruption was significantly associated with adverse perinatal outcomes such as Apgar scores?<7 at 1 and 5?min and perinatal mortality. Patients with placental abruption were more likely to have cesarean deliveries, as well as cesarean hysterectomy.Using another multivariate analysis, with perinatal mortality as the outcome variable, controlling for gestational age, hypertensive disorders, etc., placental abruption was noted as an independent risk factor for perinatal mortality.

Conclusions.?Placental abruption is an independent risk factor for perinatal mortality. Since the incidence of placental abruption has increased during the last decade, risk factors should be carefully evaluated in an attempt to improve surveillance and outcome.     

Reproductive risk factors,Doppler findings,and outcome of affected births in placental abruption: a population-based analysis

Placental abruption complicates about 1% of all singleton pregnancies and the aim of this study is to assess the reproductive maternal risk factors associated with placental abruption, and the outcome of affected births. We analyze 170 women with singleton pregnancies complicated by placental abruption who gave birth at Kuopio University Hospital from March 1989 to December 1999. The general obstetric population ( n = 22,905) was selected as the reference group and logistic regression analysis was used to identify independent reproductive risk factors. Furthermore, Doppler ultrasonographic results and pregnancy outcome measures in the two groups were also recorded. The incidence of placental abruption was 0.57% in the referral area. Preeclampsia, grand multiparity, velamentous umbilical cord insertion, cigarette smoking, prior fetal demise, advanced maternal age (>35 years), and previous miscarriage were independent risk factors of placental abruption, with adjusted relative risks of 4.39, 3.60, 2.53, 2.46, 2.02, 1.62, and 1.55, respectively. Most cases of placental abruption occur before the onset of labor in low-risk pregnancies and are not predictable with regard to maternal reproductive risk factors. Current antepartum methods of detecting uteroplacental problems, including Doppler ultrasonography, are not effective in prenatal prediction of placental abruption. The outcome of affected births is still poor.     

Risk of Fetal Death Associated With Maternal Drug Dependence and Placental Abruption: A Population-Based Study

ObjectiveSubstance use in pregnancy is associated with placental abruption, but the risk of fetal death independent of abruption remains undetermined. Our objective was to examine the effect of maternal drug dependence on placental abruption and on fetal death in association with abruption and independent of it.MethodsTo examine placental abruption and fetal death, we performed a retrospective population-based study of 1 854 463 consecutive deliveries of liveborn and stillborn infants occurring between January 1, 1995 and March 31, 2001, using the Canadian Institute for Health Information Discharge Abstract Database.ResultsMaternal drug dependence was associated with a tripling of the risk of placental abruption in singleton pregnancies (adjusted odds ratio [OR] 3.1; 95% confidence intervals [CI] 2.6–3.7), but not in multiple gestations (adjusted OR 0.88; 95% CI 0.12–6.4). Maternal drug dependence was associated with an increased risk of fetal death independent of abruption (adjusted OR 1.6: 95% CI 1.1–2.2) in singleton pregnancies, but not in multiples. Risk of fetal death was increased with placental abruption in both singleton and multiple gestations, even after controlling for drug dependence adjusted OR 11.4 in singleton pregnancy; 95% CI 10.6–12.2, and 3.4 in multiple pregnancy; 95% CI 2.4–4.9).ConclusionMaternal drug use is associated with an increased risk of intrauterine fetal death independent of placental abruption. In singleton pregnancies, maternal drug dependence is associated with an increased risk of placental abruption.     

Complications during pregnancy in women with epilepsy: population-based cohort study

Objective  To investigate whether women with epilepsy have an increased risk of complications during pregnancy and to explore the impact of antiepileptic drug (AED) use.
Design  Population-based cohort study.
Setting  Data from Medical Birth Registry of Norway based on all births in Norway 1999–2005.
Population  All births ( n  = 372 128) delivered in Norway, ensured through linkage with the National Population Registry run by Statistics Norway. All singleton births and the first child in multiple pregnancies were included, leaving 365 107 pregnancies for analyses.
Main outcome measures  Pre-eclampsia (mild and severe), gestational hypertension, eclampsia, vaginal bleeding (early and late) and preterm birth.
Results  We compared 2805 pregnancies in women with a current or past history of epilepsy (0.8%) and 362 302 pregnancies in women without a history of epilepsy. Women with epilepsy had an increased risk of mild pre-eclampsia, [odds ratio 1.3: 95% confidence interval (1.1–1.5)] and delivery before week 34 [1.2: (1.0–1.5)].
Antiepileptic drugs were used in 33.6% ( n  = 942) of the pregnant women with epilepsy. Compared to women without epilepsy, women with epilepsy and AED use had an increased risk of mild pre-eclampsia [1.8: (1.3–2.4)], gestational hypertension [1.5: (1.0–2.2)], vaginal bleeding late in pregnancy [1.9: (1.1–3.2)], and delivery before 34 weeks of gestation [1.5: (1.1–2.0)]. No significant increase in the risk of these complications was observed in women with epilepsy not using AED. These results remained unchanged after exclusion of multiple pregnancies.
Conclusion  Women with epilepsy have a low complication rate, but special attention should be paid to those using AED during pregnancy.     

Placental abruption

Placental abruption complicates approximately 1% to 2% of all pregnancies and remains a significant cause of both maternal and fetal morbidity. Proposed pathophysiology of both acute placental abruption and the more common partial placental separation are discussed. The contribution of placental abruption to both preterm labor and preterm premature rupture of membranes is discussed. Recent evidence supporting maternal hypertensive disorders, maternal tobacco and cocaine use, age and parity, multiple gestations, maternal thrombophilias, and an unexplained elevated maternal serum alphafetoprotein as risk factors for abruption is reviewed. Emergency management of acute abruption is outlined. Finally, particular emphasis is given to the management of partial placental separation, including both immediate and delayed delivery and the use of tocolysis. TARGET AUDIENCE: Obstetricians and Gynecologists, Family Physicians. LEARNING OBJECTIVES: After completion of this article, the reader will be able to define the condition of placental abruption, list the conditions associated with abruption, and outline potential management options for patients with placental abruption.     

Women with a history of placental abruption: when in a subsequent pregnancy should special surveillance for a recurrent placental abruption be initiated?

BACKGROUND: It is common to admit to hospital or start intensive ambulatory antenatal care of pregnant women with a previous placental abruption using the gestational age of the previous placental abruption as a starting point. In some instances, close surveillance may be commenced much earlier. There is no consensus when in a subsequent pregnancy such measures should be initiated. OBJECTIVE: The analyses aimed at the prevention of complicated (preterm, small for gestational age, or perinatal death) recurrent placental abruptions, assessing at which time in a subsequent pregnancy special surveillance should start in order to anticipate and prevent a recurrence. DESIGN: A cohort study based on the Medical Birth Registry of Norway. Calculation of gestational age specific risks of placental abruption in a second pregnancy and estimation of when to initiate surveillance in order to reduce an increased risk of recurrent placental abruption to the initial level of initial abruption in the second pregnancy. RESULTS: In women with a complicated (preterm, small for gestational age, or perinatal death) first delivery, the risks of an initial and recurrent complicated placental abruption in the second pregnancy were 7/1000 and 33/1000, respectively (relative risk 4.9). To reduce the recurrence risk in a second pregnancy to 7/1000, special surveillance six weeks prior to the gestational age of the initial abruption would be necessary. In women with an uncomplicated first delivery, the risks in the second pregnancy of an initial and recurrent complicated abruption were 3 and 19/1000, respectively (relative risk 7.1). To reduce the recurrence risk to 3/1000, surveillance at least 12 weeks prior would be necessary. CONCLUSION: The increased recurrence rate would necessitate increased awareness in terms of special surveillance in the second pregnancy. In pregnancies at risk of a recurrent placental abruption, monitoring up to three months before the gestational age of the initial abruption is necessary.     

Prediction of placental abruption by testing for C-reactive protein and chlamydial antibody levels in early pregnancy

Objective  Placental abruption may be a manifestation of acute and chronic inflammatory process. We wanted to assess the association of first-trimester serum C-reactive protein (CRP), Chlamydia pneumoniae antibodies, Chlamydia trachomatis antibodies or chlamydial heat-shock protein 60 (CHSP60) antibodies to placental abruption.
Design  Retrospective case–control study.
Setting  University Hospital.
Population  A total of 181 women with subsequent placental abruption and 261 control women with normal pregnancy.
Methods  Serum samples collected at first trimester (mean 10.4 gestational weeks) were analysed for CRP levels, C. pneumoniae -specific immunoglobulin G (IgG) and immunoglobulin A (IgA) antibodies and C. trachomatis -specific IgG, IgA and CHSP60 antibodies.
Main outcome measure  Placental abruption.
Results  The levels of CRP showed no difference between the cases and the controls (median 2.35 mg/l [interquartile range {IQR} 1.09–5.93] versus 2.28 mg/l [IQR 0.92–5.01], not significant). C. pneumoniae -specific IgG and IgA as well as C. trachomatis -specific IgG, IgA and CHSP60 antibody frequencies were similar between the groups. There was no association between CRP levels and chlamydial antibodies.
Conclusion  These markers of inflammation in early pregnancy failed to predict subsequent placental abruption.