Risk Of Placenta Previa Research Articles

Natural History of Placenta Previa in Twins

To estimate the incidence of placenta previa in twin pregnancies compared with singletons and to estimate the rate and gestational age of previa resolution in twin pregnancies. This was a retrospective cohort of singleton and twin pregnancies undergoing ultrasonography at 15-22 weeks of gestation and of twin pregnancies undergoing serial ultrasonography from 15 to 40 weeks of gestation. Groups were defined by singleton or twin gestation and by chorionicity of twin gestation. The primary outcomes were incidence of placenta previa in each group and the percentage of all previa resolving at 24-28, 28-32, 32-36, and 36 or more weeks of gestation. Of 67,895 pregnancies included, 2.1% (1,381 of 65,701) of singleton and 2.5% (56 of 2,194) of twin pregnancies had previa diagnosed (P=.15). Dichorionic twins had an increased risk of placenta previa compared with singletons (adjusted odds ratio 1.54, 95% confidence interval 1.15-2.06) or monochorionic twin pregnancies (relative risk 3.29, 95% confidence interval 1.32-8.21). Of the 1,738 twin pregnancies with serial ultrasound examinations, 51 (2.9%) were noted to have previa. Sixty-nine percent of the previa resolved by 32 weeks, at between 32 and 36 weeks an additional 47% of the remaining previa resolved, and no previa resolved after 36 weeks. Dichorionic twin pregnancies are at significantly increased risk for ultrasound-diagnosed previa when compared with singleton or monochorionic pregnancies. Among twin pregnancies with previa diagnosed in the second trimester, the majority of cases resolve by 32 weeks. II.

Do Women with Rectovaginal Endometriosis Have Excess Risk for Placenta Previa

Because previous studies have suggested that women with endometriosis are at higher obstetric risk than women in the general population, investigators

Increased risk of placenta previa is associated with endometriosis and tubal factor infertility in assisted reproductive technology pregnancy

Although assisted reproductive technology (ART) is suspected to increase the risk of placenta previa, a life-threatening complication of pregnancy, the reason is poorly understood. We recruited consecutive 318 pregnancies conceived by ART in our clinic and examined relation of ten variables, i.e. maternal age, gravidity, parity, male or female fetus, previous abortion, previous cesarean delivery, endometriosis, ovulatory disorder, tubal disease, and male infertility, to placenta previa, by logistic regression analysis. As a result, we found that endometriosis (odds ratio = 15.1; 95% CI = 7.6–500.0) and tubal disease (odds ratio = 4.4; 95% CI = 1.1–26.3) were significantly associated with placenta previa. It would be preferable to take the increased risk of placenta previa into account in treating ART pregnancy with endometriosis and tubal disease.

Uterine Synechiae and Pregnancy Complications

Uterine synechiae have generally been considered benign findings in pregnancy. We used a large perinatal database to test the hypothesis that uterine synechiae are associated with pregnancy complications. We performed a retrospective cohort study of women with singleton pregnancies presenting for routine ultrasonographic examinations at 17-22 weeks from 1990-2009. Pregnancies with multiple fetuses, amniotic bands, and congenital uterine anomalies were excluded. We compared pregnancy outcomes between women with and without uterine synechiae. Multivariable logistic regression was used to adjust for confounders. Of 65,518 pregnancies meeting inclusion criteria, 296 (0.45%) were diagnosed with uterine synechiae. Women with uterine synechiae were significantly more likely to have placental abruption (2.1% compared with 0.6%, adjusted odds ratio [OR] 3.25, 95% confidence interval [CI] 1.43-7.36), preterm premature rupture of membranes (PROM) (5.5% compared with 2.3%, adjusted OR 2.51, 95% CI 1.51-4.18), and cesarean delivery for malpresentation (5.1% compared with 3.0%, adjusted OR 1.75, 95% CI 1.04-2.95). The risks of placenta previa, fetal growth restriction, stillbirth, and preterm delivery were not significantly different. Uterine synechiae are associated with significant increase in the risk of preterm PROM, placental abruption, and cesarean delivery for malpresentation. The notion of uterine synechiae as benign findings in pregnancy should be re-evaluated. II.

367: Uterine synechiae are associated with an increased risk of preterm premature rupture of membranes and abruption

Uterine synechiae have generally been considered benign findings in pregnancy. We used a large perinatal database to test the hypothesis that uterine synechiae are associated with pregnancy complications. We performed a retrospective cohort study of women with singleton pregnancies presenting for routine ultrasound examinations at 17 to 22 weeks from 1990 to 2009. Pregnancies with multiple fetuses, amniotic bands, fibroids and congenital uterine anomalies were excluded. We compared pregnancy outcomes between women with and without uterine synechiae. Multivariable logistic regression was used to adjust for confounders. Of 65, 518 pregnancies meeting inclusion criteria 296 (0.45%) were diagnosed with uterine synechiae. Women with uterine synechiae were significantly more likely to have preterm premature rupture of membranes (PPROM) (5.5% vs 2.3%, aOR 2.51 [95% CI 1.51,4.18]), placental abruption (2.1% vs 0.6%, aOR 3.25 [95% CI 1.43, 7.36]) and cesarean delivery for breech presentation (5.1% vs 3.0%, OR 1.75 [95% CI 1.04, 2.94]) (Table). In contrast, the risks of placenta previa, fetal growth restriction, stillbirth and preterm delivery were not significantly increased.Tabled 1 Uterine synechiae are associated with a significant increase in the risk of PPROM and placental abruption. Therefore, the concept of uterine synechiae as benign findings in pregnancy should be re-considered.

Risk of placenta previa in second birth after first birth cesarean section: a population-based study and meta-analysis

BackgroundObjective: To compare the risk of placenta previa at second birth among women who had a cesarean section (CS) at first birth with women who delivered vaginally.MethodsRetrospective cohort study of 399,674 women who gave birth to a singleton first and second baby between April 2000 and February 2009 in England. Multiple logistic regression was used to adjust the estimates for maternal age, ethnicity, deprivation, placenta previa at first birth, inter-birth interval and pregnancy complications. In addition, we conducted a meta-analysis of the reported results in peer-reviewed articles since 1980.ResultsThe rate of placenta previa at second birth for women with vaginal first births was 4.4 per 1000 births, compared to 8.7 per 1000 births for women with CS at first birth. After adjustment, CS at first birth remained associated with an increased risk of placenta previa (odds ratio = 1.60; 95% CI 1.44 to 1.76). In the meta-analysis of 37 previously published studies from 21 countries, the overall pooled random effects odds ratio was 2.20 (95% CI 1.96-2.46). Our results from the current study is consistent with those of the meta-analysis as the pooled odds ratio for the six population-based cohort studies that analyzed second births only was 1.51 (95% CI 1.39-1.65).ConclusionsThere is an increased risk of placenta previa in the subsequent pregnancy after CS delivery at first birth, but the risk is lower than previously estimated. Given the placenta previa rate in England and the adjusted effect of previous CS, 359 deliveries by CS at first birth would result in one additional case of placenta previa in the next pregnancy.

Obstetric outcome after early placental complications

To evaluate the impact of early pregnancy complications involving placentation and early placental development on adverse obstetric outcome in ongoing and subsequent pregnancies. We found an increased risk of adverse outcome (odds ratio >2.0) in ongoing pregnancies of preterm delivery (PTD), very preterm delivery (VPTD), placental abruption, small for gestational age (SGA), low birth weight (LBW) and very LBW (VLBW) after a threatened miscarriage episode; pregnancy-induced hypertension, preeclampsia, placental abruption, PTD, SGA and low 5-min Apgar score following the detection of an intrauterine haematoma; and VPTD, VLBW and perinatal death after a vanishing twin phenomenon. In subsequent pregnancies, the risk of perinatal death was increased (odds ratio >2.0) after a single miscarriage, the risk of VPTD after two or more miscarriages, the risk of placenta previa, premature preterm rupture of membranes, PTD, VPTD and LBW after recurrent miscarriage and the risk of VPTD after two or more terminations of pregnancy. Our analysis of the literature review indicates a link between early pregnancy complications involving the placenta and subsequent adverse obstetric and perinatal outcomes. Some of these associations are based on limited or small uncontrolled studies. Larger population-based prospective controlled studies have recently been published confirming most of these findings. This suggests that the early detection of these risk factors could improve the screening of women at high risk of specific obstetric complications in ongoing and subsequent pregnancies.

Alcohol Consumption During Pregnancy and Risk of Placental Abruption and Placenta Previa

The purpose of this study was to examine the association between prenatal alcohol consumption and the occurrence of placental abruption and placenta previa in a population-based sample. We used linked birth data files to conduct a retrospective cohort study of singleton deliveries in the state of Missouri during the period 1989 through 2005 (n=1,221,310). The main outcomes of interest were placenta previa, placental abruption and a composite outcome defined as the occurrence of either or both lesions. Multivariate logistic regression was used to generate adjusted odd ratios, with non-drinking mothers as the referent category. Women who consumed alcohol during pregnancy had a 33% greater likelihood for placental abruption during pregnancy (adjusted odds ratio (OR), 95% confidence interval (CI)=1.33 [1.16-1.54]). No association was observed between prenatal alcohol use and the risk of placenta previa. Alcohol consumption in pregnancy was positively related to the occurrence of either or both placental conditions (adjusted OR [95% CI]=1.29 [1.14-1.45]). Mothers who consumed alcohol during pregnancy were at elevated risk of experiencing placental abruption, but not placenta previa. Our findings underscore the need for screening and behavioral counseling interventions to combat alcohol use by pregnant women and women of childbearing age.

Association of first Birth Cesarean Delivery and Placental Abruption or Previa at Second Birth

ABSTRACT Objective To evaluate the strength of association of cesarean delivery for first birth with placenta previa and placental abruption in second pregnancy. Design Retrospective cohort study. Setting Hospital based (Birth register)2004-2008. A total of 1638 pregnancies were available for the final analysis after excluding missing information. Methods Multiple logistic regressions were used to describe the relationship between cesarean section for first birth with placenta previa and placental abruption in second birth singletons. Main outcome measures Placenta previa and placental abruption Results Placenta previa was present in 10 per 1000 second-birth singletons whose first births delivered by cesarean section and 9 per 1000 second-birth singletons whose first births delivered vaginally. The corresponding figures for placental abruption were 5 per 1000 in the previous cesarean delivery group and 5 per 1000 in the previous vaginal delivery group. The adjusted odds ratio (95% confidence intervals) of previous cesarean section for placenta previa in following second pregnancies was 1.10 (0.39 to 3.10) after adjusting for confounders including maternal age and interval between births. The corresponding figure for placental abruption was 1.0 (0.24 to 4.19). Conclusion Cesarean section for first birth is associated with 10% increased risk of placenta previa and no risk of placental abruption in second pregnancy with a singleton.

Predicting adverse obstetric outcome after early pregnancy events and complications: a review

BACKGROUND The aim was to evaluate the impact of early pregnancy events and complications as predictors of adverse obstetric outcome. METHODS We conducted a literature review on the impact of first trimester complications in previous and index pregnancies using Medline and Cochrane databases covering the period 1980-2008. RESULTS Clinically relevant associations of adverse outcome in the subsequent pregnancy with an odds ratio (OR) > 2.0 after complications in a previous pregnancy are the risk of perinatal death after a single previous miscarriage, the risk of very preterm delivery (VPTD) after two or more miscarriages, the risk of placenta praevia, premature preterm rupture of membranes, VPTD and low birthweight (LBW) after recurrent miscarriage and the risk of VPTD after two or more termination of pregnancy. Clinically relevant associations of adverse obstetric outcome in the ongoing pregnancy with an OR > 2.0 after complications in the index pregnancy are the risk of LBW and very low birthweight (VLBW) after a threatened miscarriage, the risk of pregnancy-induced hypertension, pre-eclampsia, placental abruption, preterm delivery (PTD), small for gestational age and low 5-min Apgar score after detection of an intrauterine haematoma, the risk of VPTD and intrauterine growth restriction after a crown-rump length discrepancy, the risk of VPTD, LBW and VLBW after a vanishing twin phenomenon and the risk of PTD, LBW and low 5-min Apgar score in a pregnancy complicated by severe hyperemesis gravidarum. CONCLUSIONS Data from our literature review indicate, by finding significant associations, that specific early pregnancy events and complications are predictors for subsequent adverse obstetric and perinatal outcome. Though, some of these associations are based on limited or small uncontrolled studies. Larger population-based controlled studies are needed to confirm these findings. Nevertheless, identification of these risks will improve obstetric care.

P01-204 Gynaecological and obstetric comorbidities in patients with bipolar disorder: a systematic review

Objective:To synthesize the available knowledge on gynaecological and obstetric comorbidities in patients with bipolar disorder (BD).Methods:Relevant studies were identified by a MEDLINE search from 1966 to January 2008, and supplemented by a manual review of reference lists of the articles identified and previous review articles. We included studies with any design, in patients with BD as diagnosed by any criteria, with sample size ≥30 patients, and reporting any measure of frequency or association as regards the comorbidities. When available, priority was given to comparative studies.Results:We identified 4 studies: 3 were comparative; 1 was cross-sectional and 3 were retrospective cohort studies; 1 was population-based study; and 4 used a convenience sample. A retrospective study reported an increased risk of pregnancy complications in patients with BD (OR1.23, 95%CI 1.06-1.44) but not of labor/delivery or neonatal complications; as compared to controls, patients with BD had an increased risk of placenta previa (OR2.04, 95% CI 1.11-3.73), antepartum hemorrhage (OR 1.66, 95%CI 1.15-2.39), and drug side-effects (OR 3.94, 95%CI 1.46-10.62). In another retrospective study, patients with BD had an increased risk of endometriosis (OR: 1.93, 95%CI 1.37-2.70), inflammatory disease of ovary (OR 2.17, 95%CI 1.84-2.57), and disorders of menstruation (OR 1.79, 95%CI 1.56-2.05). In a cross-sectional study, gynaecological disorders were more common in patients with BD than in patients with schizophrenia (4% vs 1.3%).Conclusion:Although the information is scanty, available data suggest that patients with BD might have an increased risk of gynaecological and obstetric comorbidities/complications.

Pregnancy and perinatal outcomes after assisted reproduction: a comparative study

Dear Editor, We welcomed the paper by Allen et al. [1] which provides reassurance about the rate of congenital malformations in babies delivered after assisted reproductive technology (ART). Their data are in close agreement with previous research [2], where an increased risk of placenta previa after in vitro fertilisation (IVF) was identified. As Allen et al. note, however, the true incidence of stillbirth and miscarriage after IVF remains unknown, because the scope of their investigation did not include all IVF pregnancies (i.e., only deliveries known to have good perinatal outcomes were sampled). While their study did achieve a questionnaire return rate of 65% from these parents of IVF children, the study design could not identify common demographic or clinical characteristics among the non-responders. From a public health perspective, information on this important sub-group of IVF patients would be highly informative. As Allen et al. [1] correctly note, the impact of IVF on the course of pregnancy is not yet fully understood. For example, anecdotal reports of mature stillbirths in IVF patients who go beyond 40 weeks gestation have been frustrating to assess systematically. It is hoped that future epidemiologic studies will address this issue. In the meantime, we agree with others [3, 4] that in the absence of standardised protocols for the obstetric management of pregnancies conceived with IVF, it is prudent for such gestations to be regarded as high-risk.

From preterm birth, placenta and thyroid to the perineum

June this year features the 36th NFOG Congress in Reykjavik, Iceland. It promises to be an excellent event, with well over 700 participants registered. Just as Acta in its 87th year of existence, i...

Placenta previa: Its relationship with race and the country of origin among Asian women

To examine the association between placenta previa with maternal race and its variations by country of origin among Asian women. Retrospective cohort study. We analyzed data from a population-based retrospective cohort study of 16,751,627 pregnancies in the US. The data were derived from the national linked birth/infant mortality database for the period 1995-2000. Multiple logistic regressions were used to describe the relationship between placenta previa and race as well as country of origin among Asian women. About 3.3 per 1,000 pregnancies were complicated with placenta previa among white women, while the corresponding figures for black women and women of other races were 3.0 and 4.5 per 1,000 pregnancies, respectively. The excess risk remained substantial and significant after adjustment for confounders for women of other races compared to white women. The frequencies of placenta previa among Chinese, Japanese, Filipino, Asian Indian, Korean, Vietnamese and other Asian or Pacific Islander were 5.6, 5.1, 7.6, 4.5, 5.9, 4.4 and 4.4 per 1,000 pregnancies, respectively. The adjusted odds ratios ranged from 1.39 to 2.15 among Asian women by country of origin, with the lowest for Japanese and Vietnamese and the highest for Filipino women in our study. Asian women have excess risk of placenta previa compared with white women. Major variation exists in placenta previa risk among Asian women, with the lowest risk in Japanese and Vietnamese women and the highest risk in Filipino women.

ACOG Committee Opinion No. 394: Cesarean Delivery on Maternal Request

Cesarean delivery on maternal request is defined as a primary cesarean delivery at maternal request in the absence of any medical or obstetric indication. A potential benefit of cesarean delivery on maternal request is decreased risk of hemorrhage for the mother. Potential risks of cesarean delivery on maternal request include a longer maternal hospital stay, an increased risk of respiratory problems for the baby, and greater complications in subsequent pregnancies, including uterine rupture and placental implantation problems. Cesarean delivery on maternal request should not be performed before gestational age of 39 weeks has been accurately determined unless there is documentation of lung maturity . Cesarean delivery on maternal request is not recommended for women desiring several children, given that the risks of placenta previa, placenta accreta, and the need for gravid hysterectomy increase with each cesarean delivery.

Cesarean Delivery and Risk of Stillbirth in Subsequent Pregnancy: A Retrospective Cohort Study in an English Population

Rates of cesarean section have increased in the past 2 to 3 decades in the United Kingdom and elsewhere. Apart from immediate maternal and infant complications, there appears to be an increased risk of placenta previa, placental abruption, and uterine rupture during labor in subsequent pregnancies. Recent studies suggest an increased risk of stillbirth in pregnancies following cesarean delivery. The investigators attempted to clarify this risk in a retrospective cohort study of 81,784 singleton deliveries taking place in the UK in the years 1968–1989. Excluding those caused by congenital anomalies there were 290 stillbirths, 113 of which were classified as explained, and 177 as unexplained. Mothers having a previous cesarean delivery tended to be older than the others, to have lower parity, to be of higher social class, and to have had previous adverse pregnancy outcomes. Unadjusted hazard ratios for all stillbirths, those that were explained, and those unexplained were, respectively, 1.54 (95% confidence interval [CI], 1.04–2.29), 2.13 (95% CI, 1.22–3.72), and 1.19 (95% CI, 0.68–2.09). After adjusting for maternal age, parity, social class, previous adverse pregnancy outcomes, body mass index, and smoking status, the respective hazard ratios were 1.58 (95% CI, 0.95–2.63), 2.08 (95% CI, 1.00–4.31), and 1.24 (95% CI, 0.60–2.56). Stillbirths following a previous cesarean section were more likely than in the “unexposed” group to be explained, and they were likelier to be associated with abruption/hemorrhage or mechanical causes. It was estimated, using a hazard ratio of 1.58 to approximate the adjusted relative risk in a population with a section rate of 7.1% and an average stillbirth rate of 0.35%, that approximately 4% of all stillbirths in the population may be ascribed to previous cesarean delivery. These findings affirm an increased risk of stillbirth in women previously having a cesarean section. The risk is most evident in cases of explained stillbirth. Further research is needed to determine whether this association is causal and, if so, what mechanisms might be involved.

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

To quantify the risk of placenta praevia and placental abruption in singleton, second pregnancies after a caesarean delivery of the first pregnancy. Retrospective cohort study. Linked birth and infant mortality database of the USA between 1995 and 2000. A total of 5,146,742 singleton second pregnancies were available for the final analysis after excluding missing information. 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. Placenta praevia and placental abruption. 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). 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.

Previous Cesarean Delivery and Risks of Placenta Previa and Placental Abruption

Previous Cesarean Delivery and Risks of Placenta Previa and Placental Abruption

Predicting parity as a prerequisite for cesarean delivery on maternal request: Does a woman know how many children she will have?

For cesarean delivery on maternal request (CDMR) to be an appropriate treatment option, women must be able to accurately predict their final parity (the risk of placenta previa, accreta and surgical complications increase with each CD). We sought to determine the accuracy with which women, at the time of their first pregnancy, were able to predict their final parity.

Previous Cesarean Delivery and Risks of Placenta Previa and Placental Abruption

Previous Cesarean Delivery and Risks of Placenta Previa and Placental Abruption