OBJECTIVE DATA: The objective of this study was to evaluate the prevalence of placenta accreta spectrum in general population studies and the main maternal outcomes at delivery. STUDY: We searched PubMed, Google Scholar, clinicalTrials.gov, and MEDLINE between 1982 and 2018. Articles that provided data on the number of cases of placenta accreta spectrum per pregnancies, births, or deliveries in a defined population were used. STUDY APPRAISAL AND SYNTHESIS
Methods
Study characteristics were evaluated by 2 independent reviewers who used a predesigned protocol. Primary outcomes were the prevalence of placenta accreta spectrum and clinical diagnostic data at birth; the pathologic criteria were used to confirm the diagnosis. Secondary outcomes included cases that required transfusion, incidence of peripartum hysterectomy, and maternal mortality rates. Heterogeneity between studies was analyzed with the Cochran's Q-test and the I2 statistics.
Results
Of the 98 full-text studies that were identified, 29 articles met the defined criteria and included 22 retrospective and 7 prospective studies comprising 7001 cases of placenta accreta spectrum of 5,719,992 births. Prevalence rates ranged from 0.01-1.1% with an overall pooled prevalence of 0.17% (95% confidence interval, 0.14-0.19). Only 10 studies provided detailed histopathologic data. The pool prevalence for the adherent vs the invasive grades was 0.5 (95% confidence interval, 0.3-0.36) and 0.3 (95% confidence interval, 0.2-0.4) per 1000 births, respectively. The pooled incidence for peripartum hysterectomy was 52.2% (95% confidence interval, 38.3-66.4; I2=99.8%) and 46.9% (95 % confidence interval, 34-59.9; I2=98.8%) for hemorrhage that required transfusion. The pooled estimate of maternal death was 0.05% (95% confidence interval, 0.06-0.69; I2=73%). We found large amounts of heterogeneity between studies for all parameters and further quantification was limited because of methodologic inconsistencies between studies with regards to clinical criteria that were used for the diagnosis of the condition at birth and the histopathologic confirmation of the diagnosis and differential diagnosis between adherent and invasive accreta placentation.
Conclusion
This meta-analysis indicated wide variation between studies for the prevalence rate of placenta accreta spectrum and for the different grades of accreta placentation that highlighted the need for consistency in definitions that are used to describe placenta accreta spectrum at birth and in the reporting of this increasing common obstetric complication.
PMID 30716286 30716286 DOI 10.1016/j.ajog.2019.01.233 10.1016/j.ajog.2019.01.233 Jauniaux et al. 2019, Jauniaux 2019
Cite this article
Jauniaux, E., Bunce, C., Grønbeck, L., & Langhoff-Roos, J. (2019). Prevalence and main outcomes of placenta accreta spectrum: a systematic review and meta-analysis. American Journal of Obstetrics and Gynecology. https://doi.org/10.1016/j.ajog.2019.01.233
Jauniaux E, Bunce C, Grønbeck L, Langhoff-Roos J. Prevalence and main outcomes of placenta accreta spectrum: a systematic review and meta-analysis. American Journal of Obstetrics and Gynecology. 2019. doi:10.1016/j.ajog.2019.01.233
Jauniaux, E., et al. "Prevalence and main outcomes of placenta accreta spectrum: a systematic review and meta-analysis." American Journal of Obstetrics and Gynecology, 2019.
To assess the cervicovaginal fetal fibronectin test to predict preterm delivery. We searched MEDLINE, Current Contents, Index Medicus, and proceedings of meetings for studies published between 1991 and June 1997. Inclusion criteria were prospective cohort study; test performed between 20 and 36 weeks' gestation; fetal fibronectin measured by a previously described assay, with a cutoff level set at 50 ng/mL; test results not disclosed to women or physicians; and fewer than 20% of study participants excluded from the analysis. TABULATION, INTEGRATION, Twenty-nine relevant studies were stratified according to the prevalence of preterm delivery, the number of tests performed, and delivery before 34, 35, or 37 weeks. Sensitivities, specificities, and likelihood ratios were calculated in each study. The summary estimates of the likelihood ratio for tests yielding positive results or tests yielding negative results along with their 95% confidence intervals (CIs) were computed in each stratum according to a random-effects model. All summary likelihood ratios for a test yielding positive results indicated a significant association with preterm delivery. The strongest association was found between a single test with positive results and delivery before 37 weeks in a low-risk population (likelihood ratio 7.5; 95% CI 4.6, 12.3). This association also was found in high-risk women (likelihood ratio 3.5; 95% CI 2.6, 4.6). In high-risk women, a test yielding negative results was associated with a reduction in risk of preterm delivery (likelihood ratio 0.4; 95% CI 0.3, 0.5). Fetal fibronectin in cervicovaginal secretions is associated with preterm delivery in both high-risk and low-risk women.
The relationship between asymptomatic bacteriuria and prematurity/low birth weight (LBW) is still a controversial issue, despite many studies. Meta-analysis, a research tool designed to analyze and combine the results of previous studies, may resolve this discrepancy among contradictory results of clinical trials. The purpose of this study was to examine the relationship between asymptomatic bacteriuria and preterm delivery/LBW using meta-analysis. Reports from the literature were classified according to study design into cohort or randomized-treatment control trials. Meta-analysis of cohort studies showed that untreated asymptomatic bacteriuria during pregnancy significantly increased rates of LBW and preterm delivery. Nonbacteriuric patients had only about two-thirds the risk (typical relative risk = 0.65; 95% confidence interval 0.57, 0.74) of LBW and half the risk (typical relative risk = 0.50; 95% confidence interval 0.36, 0.70) of preterm delivery of those with untreated asymptomatic bacteriuria. These reduced risks correspond to a 3.4 (confidence interval 1.8, 5.0) percentage-point difference in LBW and a 3.8 (1.1, 6.4) percentage-point difference in preterm delivery. The analysis of randomized clinical trials showed that antibiotic treatment significantly reduced the risk of LBW (typical relative risk = 0.56; 95% confidence interval 0.43, 0.73), with a substantial reduction of 6.4 (confidence interval 3.3, 9.5) percentage points in the rate of LBW. We conclude that clinical and epidemiologic evidence indicates a strong association between untreated asymptomatic bacteriuria and LBW/preterm delivery and that antibiotic treatment is effective in reducing the occurrence of LBW.
Spontaneous preterm birth significantly increases the risk for a recurrent preterm birth. Only a few identifiable clinical risk factors can be referenced in counseling for recurrent preterm birth. Furthermore, treatment using progesterone supplementation has not consistently prevented preterm birth among high-risk patients, but it may be effective in a subset of those patients. Placental pathology from a previous pregnancy may be used to predict which patients will experience a recurrent preterm birth or to identify a subset of patients more likely to respond to treatment with antenatal progesterone. This study aimed to determine if histologic patterns are associated with recurrent preterm birth among patients with an index spontaneous preterm birth. A secondary objective was to determine if placental histologic types and/or progesterone receptor density in the decidua are associated with the response to progesterone supplementation with intramuscular 17-hydroxyprogesterone caproate. This was a retrospective cohort study at a single institution of women with singleton pregnancies with an index spontaneous preterm birth and a subsequent birth within the same hospital system between 2009 and 2019. Patients were included if placental pathology was available for the index spontaneous preterm birth. A logistic regression was used to determine if there were independent associations between 4 histologic types (acute inflammation, maternal vascular malperfusion, fetal vascular malperfusion, chronic inflammation) and recurrent preterm birth. For the secondary endpoint, 17-hydroxyprogesterone caproate response was defined as prolonging gestation by >3 weeks beyond the gestational age at delivery in the index pregnancy. Patients who delivered <3 weeks beyond the gestational age in the index pregnancy but at ≥39 weeks' gestation were excluded. A logistic regression was used to assess the independent association between placental histology and 17-hydroxyprogesterone caproate response. Sensitivity analyses were completed using only patients with an index birth <36 weeks' gestation, and then excluding those with medically indicated preterm birth in a subsequent pregnancy. A nested case-control immunohistochemical study was done among 20 patients with a subsequent term birth and 20 patients with a subsequent spontaneous preterm birth. The percentage of cells in the maternal decidua positive for progesterone receptors was correlated with the subsequent pregnancy outcome. A total of 352 patients were included. Acute inflammation was the most common histologic type seen among patients with spontaneous preterm birth (44.1%), followed by chronic inflammation (40.9%) and maternal vascular malperfusion (31.3%). No histologic type was independently associated with recurrent preterm birth. A total of 155 patients received 17-hydroxyprogesterone caproate in a second pregnancy. Low-grade acute inflammation was significantly associated with a decreased likelihood of 17-hydroxyprogesterone caproate response. Low-grade maternal vascular malperfusion among those with an index pregnancy delivered at <36 weeks' gestation was significantly associated with a more than 4 times increased likelihood of 17-hydroxyprogesterone caproate response when excluding those with a subsequent iatrogenic preterm birth. Progesterone receptor staining was not associated with recurrent preterm birth. Although acute inflammation was prevalent among spontaneous preterm births, more than half of the spontaneous preterm births were not associated with acute inflammation. Low-grade acute inflammation was associated with a significantly decreased response to 17-hydroxyprogesterone caproate supplementation. Low-grade maternal vascular malperfusion was associated with a 4-fold increased likelihood of 17-hydroxyprogesterone caproate response among those with index deliveries <36 weeks' gestation. Further work is needed to determine if placental pathologic examination can be used to target treatment in subsequent pregnancies to prevent recurrent preterm birth.
Sklar A et al., 2022·American journal of obstetrics and gynecology
After preterm premature rupture of membranes at <24 weeks' gestation, pregnant women may choose continuation (expectant management) or termination of pregnancy, via either dilation and evacuation or labor induction. Neonatal outcomes after expectant management are well described. In contrast, limited research addresses maternal outcomes associated with expectant management compared to termination of pregnancy. This study aimed to compare maternal morbidity after preterm premature rupture of membranes at <24 weeks' gestation in women who choose either expectant management or termination of pregnancy. This retrospective cohort study included women with preterm premature rupture of membranes between 14 0/7 and 23 6/7 weeks' gestation with singleton or twin pregnancies at 3 institutions from 2011 to 2018. We excluded pregnancies complicated by fetal anomalies, rupture of membranes immediately after obstetrical procedures (chorionic villus sampling, amniocentesis, cerclage placement, fetal reduction), spontaneous delivery <24 hours after membrane rupture, and contraindications to expectant management. Our primary outcome was the difference in composite maternal morbidity between women choosing expectant management and women choosing termination of pregnancy. We defined composite maternal morbidity as at least 1 of the following: chorioamnionitis, endometritis, sepsis, unplanned operative procedure after delivery (dilation and curettage, laparoscopy, or laparotomy), injury requiring repair, unplanned hysterectomy, unplanned hysterotomy (excluding cesarean delivery), uterine rupture, hemorrhage of >1000 mL, transfusion, admission to the maternal intensive care unit, acute renal insufficiency, venous thromboembolism, pulmonary embolism, and readmission to the hospital within 6 weeks. We compared the demographic and antenatal characteristics of women choosing expectant management with that of women choosing termination of pregnancy and used logistic regression to quantify the association between initial management decision and composite maternal morbidity. We identified 350 women with pregnancies complicated by preterm premature rupture of membranes at <24 weeks' gestation, and 208 women were eligible for the study. Of the 208 women, 108 (51.9%) chose expectant management as initial management, and 100 (48.1%) chose termination of pregnancy as initial management. Among women selecting termination of pregnancy, 67.0% underwent labor induction, and 33.0% underwent dilation and evacuation. Compared to women who chose termination of pregnancy, women who chose expectant management had 4.1 times the odds of developing chorioamnionitis (38.0% vs 13.0%; 95% confidence interval, 2.03-8.26) and 2.44 times the odds of postpartum hemorrhage (23.1% vs 11.0%; 95% confidence interval, 1.13-5.26). Admissions to the intensive care unit and unplanned hysterectomy only occurred after expectant management (2.8% vs 0.0% and 0.9% vs 0.0%). Of women who chose expectant management, 36.2% delivered via cesarean delivery with 56.4% non-low transverse uterine incisions. Composite maternal morbidity rates were 60.2% in the expectant management group and 33.0% in the termination of pregnancy group. After adjusting for gestational age at rupture, site, race and ethnicity, gestational age at entry to prenatal care, preterm premature rupture of membranes in a previous pregnancy, twin pregnancy, smoking, cerclage, and cervical examination at the time of presentation, expectant management was associated with 3.47 times the odds of composite maternal morbidity (95% confidence interval, 1.52-7.93), corresponding to an adjusted relative risk of 1.91 (95% confidence interval, 1.35-2.73). Among women who chose expectant management, 15.7% avoided morbidity and had a neonate who survived to discharge. Expectant management for preterm premature rupture of membranes at <24 weeks' gestation was associated with a significantly increased risk of maternal morbidity when compared to termination of pregnancy.