-
Ultrasound in Obstetrics & Gynecology :... Apr 2023To determine, by expert consensus through a modified Delphi process, the role of standardized and new ultrasound signs in the prenatal evaluation of patients at high...
OBJECTIVE
To determine, by expert consensus through a modified Delphi process, the role of standardized and new ultrasound signs in the prenatal evaluation of patients at high risk of placenta accreta spectrum (PAS).
METHODS
A systematic review of articles providing information on ultrasound imaging signs or markers associated with PAS was performed before the development of questionnaires for the first round of the Delphi process. Only peer-reviewed original research studies in the English language describing one or more new ultrasound sign(s) for the prenatal evaluation of PAS were included. A three-round consensus-building Delphi method was then conducted under the guidance of a steering group, which included nine experts who invited an international panel of experts in obstetric ultrasound imaging in the evaluation of patients at high risk for PAS. Consensus was defined as agreement of ≥ 70% between participants.
RESULTS
The systematic review identified 15 articles describing eight new ultrasound signs for the prenatal evaluation of PAS. A total of 35 external experts were approached, of whom 31 agreed and participated in the first round. Thirty external experts (97%) and seven experts from the steering group completed all three Delphi rounds. A consensus was reached that a prior history of at least one Cesarean delivery, myomectomy or PAS should be an indication for detailed PAS ultrasound assessment. The panelists also reached a consensus that seven of the 11 conventional signs of PAS should be included in the examination of high-risk patients and the routine mid-gestation scan report: (1) loss of the 'clear zone', (2) myometrial thinning, (3) bladder-wall interruption, (4) placental bulge, (5) uterovesical hypervascularity, (6) placental lacunae and (7) bridging vessels. A consensus was not reached for any of the eight new signs identified by the systematic review. With respect to other ultrasound features that are not specific to PAS but increase the probability of PAS at birth, the panelists reached a consensus for the finding of anterior placenta previa or placenta previa with cervical involvement. The experts were also asked to determine which PAS signs should be quantified and consensus was reached only for the quantification of placental lacunae using an existing score. For predicting surgical outcome in patients with a high probability of PAS at delivery, a consensus was obtained for loss of the clear zone, bladder-wall interruption, presence of placental lacunae and presence of placenta previa involving the cervix.
CONCLUSIONS
We have confirmed the continued importance of seven established standardized ultrasound signs of PAS, highlighted the role of transvaginal ultrasound in evaluating the placental position and anatomy of the cervix, and identified new ultrasound signs that may become useful in the future prenatal evaluation and management of patients at high risk for PAS at birth. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.
Topics: Infant, Newborn; Pregnancy; Female; Humans; Placenta Accreta; Placenta; Placenta Previa; Delphi Technique; Ultrasonography; Ultrasonography, Prenatal; Retrospective Studies
PubMed: 36609827
DOI: 10.1002/uog.26155 -
PloS One 2017The global burden of postpartum hemorrhage (PPH) in women with placenta previa is a major public health concern. Although there are different reports on the incidence of... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
The global burden of postpartum hemorrhage (PPH) in women with placenta previa is a major public health concern. Although there are different reports on the incidence of PPH in different countries, to date, no research has reviewed them.
OBJECTIVE
The aim of this study was to calculate the average point incidence of PPH in women with placenta previa.
METHODS
A systematic review and meta-analysis of observational studies estimating PPH in women with placenta previa was conducted through literature searches in four databases in Jul 2016. This study was totally conducted according to the MOOSE guidelines and in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses standard.
RESULTS
From 1148 obtained studies, 11 included in the meta-analysis, which involved 5146 unique pregnant women with placenta previa. The overall pooled incidence of PPH was 22.3% (95% CI 15.8-28.7%). In the subgroup, the prevalence was 27.4% in placenta previas, and was 14.5% in low-lying placenta previa; the highest prevalence was estimated in Northern America (26.3%, 95%CI 11.0-41.6%), followed by the Asia (20.7%, 95%CI 12.8-28.6%), Australia (19.2%, 95% CI 17.2-21.1%) and Europe (17.8%, 95% CI, 11.5%-24.0%).
CONCLUSIONS
The summary estimate of the incidence of PPH among women with placenta previa was considerable in this systematic review. The results will be crucial in prevention, treatment, and identification of PPH among pregnant women with placenta previa and will be contributed to the planning and implantation of relevant public health strategies.
Topics: Adult; Female; Humans; Incidence; Placenta Previa; Postpartum Hemorrhage; Pregnancy
PubMed: 28107460
DOI: 10.1371/journal.pone.0170194 -
Journal of Endocrinological... Jun 2023To examine the association between isolated maternal hypothyroxinaemia (IMH) and adverse obstetric outcomes and offspring outcomes and also investigate the effects of... (Meta-Analysis)
Meta-Analysis
OBJECTIVE
To examine the association between isolated maternal hypothyroxinaemia (IMH) and adverse obstetric outcomes and offspring outcomes and also investigate the effects of levothyroxine therapy on IMH for the above outcomes.
METHODS
We systematically searched PubMed, EMBASE, and Cochrane Library, and the reference lists of key reviews were hand searched on June 9, 2021. Two authors independently screened titles/abstracts. Full articles were further assessed if the information suggested that the study met the inclusion/exclusion criteria, and two researchers performed data extraction and risk-of-bias assessment using standardized tables. Summary relative risks or the mean difference between maternal effects and offspring outcomes were calculated by a random-effects model.
RESULTS
We identified 38 eligible articles (35 cohort studies and two randomized controlled trials [RCT]). Meta-analysis showed that maternal IMH was associated with increased gestational diabetes mellitus, preterm premature rupture of membranes, preterm birth, fetal distress, and macrosomia outcomes in IMH compared to euthyroid women, and the relative risks were 1.42 (1.03-1.96), 1.50 (1.05-2.14), 1.33 (1.15-1.55), 1.75 (1.16-2.65) and 1.62 (1.35-1.94), respectively. IMH was not associated with placenta previa, gestational hypertension, pre-eclampsia, intrauterine growth restriction, and offspring outcomes like birth weight, low birth weight infants, fetal macrosomia, neonatal intensive care, neonatal death, or fetal head circumference. In addition, we did not find an association between IMH and adverse offspring cognitive defects. Due to insufficient data for meta-analysis, it failed to pool the evidence of levothyroxine's therapeutic effect on IMH and their offspring.
CONCLUSIONS AND RELEVANCE
IMH in pregnancy may relate to a few maternal and offspring outcomes. Moreover, there is currently no sufficient evidence that levothyroxine treatment during pregnancy reduces adverse maternal outcomes and disability in offspring. Further investigation to explore the beneficial effects of levothyroxine therapy is warranted.
Topics: Pregnancy; Infant, Newborn; Female; Humans; Thyroxine; Premature Birth; Diabetes, Gestational; Pre-Eclampsia; Birth Weight
PubMed: 36422828
DOI: 10.1007/s40618-022-01967-4 -
Cureus Aug 2023Deciduosis is an ectopic transformation of connective tissue into decidual-like cells. This is the first systematic review describing the clinical course, associated... (Review)
Review
Cervical and Vaginal Deciduosis: Insights on Management and a Systematic Review of Observational Studies on Pregnancy Complications and Management Outcomes (Including Vaginal Birth).
INTRODUCTION
Deciduosis is an ectopic transformation of connective tissue into decidual-like cells. This is the first systematic review describing the clinical course, associated pregnancy complications, and management outcomes of cervical and vaginal deciduosis.
METHODS
Our search covered worldwide observational studies published in English in five databases (PubMed, PubMed Central (PMC), Europe PMC, ScienceDirect, and Google Scholar) from inception to February 24, 2023. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines and critically appraised studies using CAse REport (CARE) and Joanna Briggs Institute (JBI) tools. Then, we extracted patient characteristics, clinical features, management-related information, and outcomes.
RESULTS
The selection process identified 15 studies describing 30 pregnancies. Macroscopic cervical and vaginal deciduosis presented as recurrent vaginal bleeding in over 16 of 24 women (57%). Differential diagnoses included miscarriages, cervical pregnancy, placenta previa, and malignancy. Significant antenatal hemorrhages, preterm rupture of membranes, and preterm birth were the most frequent pregnancy complications. Only one of 27 electively performed procedures resulted in biopsy-induced uncontrolled vaginal bleeding (0.04%), suggesting the relative safety of the interventions. Lesion resection led to the cessation of recurrent symptoms in eight of eight patients (100%) compared to eight of 15 women (53%) under observation management. All women with polypoid deciduosis over 1.5 cm entered labor and delivered without complications.
CONCLUSIONS
We described the clinical course, pregnancy complications, diagnostic-related challenges, management, and associated outcomes in women with macroscopic cervical and vaginal deciduosis. We supported the analysis with the current state of the problem and discovered gaps for prospective studies.
PubMed: 37791171
DOI: 10.7759/cureus.44479 -
Frontiers in Endocrinology 2023To investigate the effect of embryo stage at the time of transfer on obstetric and perinatal outcomes in programmed frozen-thawed embryo transfer (FET) versus natural... (Meta-Analysis)
Meta-Analysis
The influence of embryo stage on obstetric complications and perinatal outcomes following programmed compared to natural frozen-thawed embryo transfer cycles: a systematic review and meta-analysis.
OBJECTIVE
To investigate the effect of embryo stage at the time of transfer on obstetric and perinatal outcomes in programmed frozen-thawed embryo transfer (FET) versus natural FET cycles.
DESIGN
Systematic review and meta-analysis.
SETTING
Not applicable.
PATIENTS
Women with programmed frozen-thawed embryo transfer (FET) and natural FET.
INTERVENTIONS
The PubMed, MEDLINE, and EMBASE databases and the Cochrane Central Register of Controlled Trials (CCRT) were searched from 1983 to October 2022. Twenty-three observational studies were included.
PRIMARY OUTCOME MEASURE
The primary outcomes were hypertensive disorders of pregnancy (HDPs), gestational hypertension and preeclampsia (PE). The secondary outcomes were gestational diabetes mellitus (GDM), placenta previa, postpartum haemorrhage (PPH), placental abruption, preterm premature rupture of membranes (PPROM), large for gestational age (LGA), small for gestational age (SGA), macrosomia, and preterm delivery (PTD).
RESULTS
The risk of HDP (14 studies, odds ratio (OR) 2.17; 95% confidence interval (CI) 1.95-2.41; P<0.00001; I = 43%), gestational hypertension (11 studies, OR 1.38; 95% CI 1.15-1.66; P=0.0006; I = 19%), PE (12 studies, OR 2.09; 95% CI 1.88-2.32; P<0.00001; I = 0%), GDM (20 studies, OR 1.09; 95% CI 1.02-1.17; P=0.02; I = 8%), LGA (18 studies, OR 1.11; 95% CI 1.07-1.15; P<0.00001; I = 46%), macrosomia (12 studies, OR 1.15; 95% CI 1.07-1.24; P=0.0002; I = 31%), PTD (22 studies, OR 1.21; 95% CI 1.15-1.27; P<0.00001; I = 49%), placenta previa (17 studies, OR 1.2; 95% CI 1.02-1.41; P=0.03; I = 11%), PPROM (9 studies, OR 1.19; 95% CI 1.02-1.39; P=0.02; I = 40%), and PPH (12 studies, OR 2.27; 95% CI 2.02-2.55; P <0.00001; I = 55%) were increased in programmed FET cycles versus natural FET cycles with overall embryo transfer. Blastocyst transfer had a higher risk of HDP (6 studies, OR 2.48; 95% CI 2.12-2.91; P<0.00001; I = 39%), gestational hypertension (5 studies, OR 1.87; 95% CI 1.27-2.75; P=0.002; I = 25%), PE (6 studies, OR 2.23; 95% CI 1.93-2.56; P<0.00001; I = 0%), GDM (10 studies, OR 1.13; 95% CI 1.04-1.23; P=0.005; I = 39%), LGA (6 studies, OR 1.14; 95% CI 1.07-1.21; P<0.0001; I = 9%), macrosomia (4 studies, OR 1.15; 95% CI 1.05-1.26; P<0.002; I = 68%), PTD (9 studies, OR 1.43; 95% CI 1.31-1.57; P<0.00001; I = 22%), PPH (6 studies, OR 1.92; 95% CI 1.46-2.51; P<0.00001; I = 55%), and PPROM (4 studies, OR 1.45; 95% CI 1.14-1.83; P=0.002; I = 46%) in programmed FET cycles than in natural FET cycles. Cleavage-stage embryo transfers revealed no difference in HDPs (1 study, OR 0.81; 95% CI 0.32-2.02; P=0.65; I not applicable), gestational hypertension (2 studies, OR 0.85; 95% CI 0.48-1.51; P=0.59; I = 0%), PE (1 study, OR 1.19; 95% CI 0.58-2.42; P=0.64; Inot applicable), GDM (3 study, OR 0.79; 95% CI 0.52-1.20; P=0.27; I = 21%), LGA (1 study, OR 1.15; 95% CI 0.62-2.11; P=0.66; Inot applicable), macrosomia (1 study, OR 1.22; 95% CI 0.54-2.77; P=0.64; I not applicable), PTD (2 studies, OR 1.05; 95% CI 0.74-1.49; P=0.79; I = 0%), PPH (1 study, OR 1.49; 95% CI 0.85-2.62; P=0.17; Inot applicable), or PPROM (2 studies, OR 0.74; 95% CI 0.46-1.21; P=0.23; I = 0%) between programmed FET cycles and natural FET cycles.
CONCLUSIONS
The risks of HDPs, gestational hypertension, PE, GDM, LGA, macrosomia, SGA, PTD, placenta previa, PPROM, and PPH were increased in programmed FET cycles versus natural FET cycles with overall embryo transfer and blastocyst transfer, but the risks were not clear for cleavage-stage embryo transfer.
Topics: Pregnancy; Infant, Newborn; Humans; Female; Hypertension, Pregnancy-Induced; Fetal Macrosomia; Placenta; Placenta Previa; Pre-Eclampsia; Diabetes, Gestational; Embryo Transfer
PubMed: 37664838
DOI: 10.3389/fendo.2023.1186068 -
Journal of Perinatal Medicine Aug 2019Background Whether placental location confers specific neonatal risks is controversial. In particular, whether placenta previa is associated with intra-uterine growth... (Meta-Analysis)
Meta-Analysis
Background Whether placental location confers specific neonatal risks is controversial. In particular, whether placenta previa is associated with intra-uterine growth restriction (IUGR)/small for gestational age (SGA) remains a matter of debate. Methods We searched Medline, EMBASE, Google Scholar, Scopus, ISI Web of Science and Cochrane database search, as well as PubMed (www.pubmed.gov) until the end of December 2018 to conduct a systematic review and meta-analysis to determine the risk of IUGR/SGA in cases of placenta previa. We defined IUGR/SGA as birth weight below the 10th percentile, regardless of the terminology used in individual studies. Risk of bias was assessed using the Cochrane Handbook for Systematic Reviews of Interventions. We used odds ratios (OR) and a fixed effects (FE) model to calculate weighted estimates in a forest plot. Statistical homogeneity was checked with the I2 statistic using Review Manager 5.3.5 (The Cochrane Collaboration, 2014). Results We obtained 357 records, of which 13 met the inclusion criteria. All study designs were retrospective in nature, and included 11 cohort and two case-control studies. A total of 1,593,226 singleton pregnancies were included, of which 10,575 had a placenta previa. The incidence of growth abnormalities was 8.7/100 births in cases of placenta previa vs. 5.8/100 births among controls. Relative to cases with alternative placental location, pregnancies with placenta previa were associated with a mild increase in the risk of IUGR/SGA, with a pooled OR [95% confidence interval (CI)] of 1.19 (1.10-1.27). Statistical heterogeneity was high with an I2 = 94%. Conclusion Neonates from pregnancies with placenta previa have a mild increase in the risk of IUGR/SGA.
Topics: Female; Fetal Growth Retardation; Humans; Infant, Newborn; Infant, Small for Gestational Age; Placenta Previa; Pregnancy; Pregnancy Outcome; Risk Assessment
PubMed: 31301678
DOI: 10.1515/jpm-2019-0116 -
Reproduction & Fertility Jan 2023Endometriosis is a chronic and debilitating condition which can affect the entire reproductive life course of women with a potentially detrimental effect on pregnancy.... (Meta-Analysis)
Meta-Analysis Review
ABSTRACT
Endometriosis is a chronic and debilitating condition which can affect the entire reproductive life course of women with a potentially detrimental effect on pregnancy. Pregnancy (and increasing parity) can affect endometriosis by modulating disease severity and suppressing symptoms. Multiparous women could be less likely to suffer from endometriosis-related pregnancy complications than primiparous women. We aimed to systematically review the evidence examining the role of parity in the relationship between pregnancy outcomes and endometriosis. A systematic search of MEDLINE, EMBASE, CINAHL, Web of Science, and Cochrane Library was performed from inception to May 2022. We searched for experimental and observational studies. Grading of Recommendations, Assessment, Development, and Evaluation was used to assess the quality of evidence with the risk of bias in non-randomised studies of interventions tool incorporated. Eleven studies were included in the meta-analysis. Primiparous women with endometriosis had almost double the risk of hypertensive disorders of pregnancy (OR: 1.99, 95% CI: 1.50-2.63, P < 0.001) compared to multiparous women with endometriosis. Primiparous women with endometriosis were at significantly increased risk of preterm delivery, caesarean delivery, and placenta praevia compared to primiparous women without endometriosis. There were no significant differences in outcomes when multiparous women with endometriosis were compared to multiparous women without endometriosis. There is limited evidence to suggest that primiparous women with endometriosis may be at higher risk of adverse pregnancy outcomes compared to multiparous women. The modulatory role of parity in the pathophysiology of endometriosis and its impact on pregnancy outcomes should be investigated.
LAY SUMMARY
Endometriosis can adversely affect pregnancy and cause complications that can affect both mother and baby. The severity and symptoms of endometriosis are lessened in pregnancy and with increasing births. Women who have previously given birth could experience fewer pregnancy complications than women giving birth for the first time. We reviewed the literature to compare pregnancy outcomes in women with endometriosis by whether they had given birth before or not. Our review included 11 studies. More women with endometriosis giving birth for the first time had blood pressure disorders in pregnancy than women with endometriosis who had given birth before. First-time mothers with endometriosis tended to have a baby born early, caesarean delivery, and an abnormally located placenta compared to those without endometriosis. This study supports the theory that women with endometriosis in their first pregnancy are at higher risk of complications and may benefit from additional monitoring.
Topics: Animals; Pregnancy; Female; Parity; Endometriosis; Pregnancy Outcome; Parturition; Pregnancy Complications
PubMed: 36821517
DOI: 10.1530/RAF-22-0070 -
Human Reproduction (Oxford, England) Oct 2018How is endometriosis associated with adverse maternal, fetal and neonatal outcomes of pregnancy? (Meta-Analysis)
Meta-Analysis
STUDY QUESTION
How is endometriosis associated with adverse maternal, fetal and neonatal outcomes of pregnancy?
SUMMARY ANSWER
Women with endometriosis are at elevated risk for serious and important adverse maternal (pre-eclampsia, gestational diabetes, placenta praevia and Cesarean section) and fetal or neonatal outcomes (preterm birth, PPROM, small for gestational age, stillbirth and neonatal death).
WHAT IS KNOWN ALREADY
A number of studies have shown an association between endometriosis and certain adverse maternal and fetal outcomes, but the results have been conflicting with potential for confounding by the use of assisted reproductive technology.
STUDY DESIGN, SIZE, DURATION
A systematic review and meta-analysis of observational studies (1 January 1990-31 December 2017) that evaluated the effect of endometriosis on maternal, fetal and neonatal outcomes was conducted.
PARTICIPANTS/MATERIALS, SETTING, METHODS
Studies were considered for inclusion if they were prospective or retrospective cohort or case-control studies; included women greater than 20 weeks gestational age with endometriosis; included a control group of gravid women without endometriosis; and, reported at least one of the outcomes of interest. Each study was reviewed for inclusion, data were extracted and risk of bias was assessed by two independent reviewers.
MAIN RESULTS AND THE ROLE OF CHANCE
The search strategy identified 33 studies (sample size, n = 3 280 488) for inclusion. Compared with women without endometriosis, women with endometriosis had higher odds of pre-eclampsia (odds ratio [OR] = 1.18 [1.01-1.39]), gestational hypertension and/or pre-eclampsia (OR = 1.21 [1.05-1.39]), gestational diabetes (OR = 1.26 [1.03-1.55]), gestational cholestasis (OR = 4.87 [1.85-12.83]), placenta praevia (OR = 3.31 [2.37, 4.63]), antepartum hemorrhage (OR = 1.69 [1.38-2.07]), antepartum hospital admissions (OR = 3.18 [2.60-3.87]), malpresentation (OR = 1.71 [1.34, 2.18]), labor dystocia (OR = 1.45 [1.04-2.01]) and cesarean section (OR = 1.86 [1.51-2.29]). Fetuses and neonates of women with endometriosis were also more likely to have preterm premature rupture of membranes (OR = 2.33 [1.39-3.90]), preterm birth (OR = 1.70 [1.40-2.06]), small for gestational age <10th% (OR = 1.28 [1.11-1.49]), NICU admission (OR = 1.39 [1.08-1.78]), stillbirth (OR = 1.29 [1.10, 1.52]) and neonatal death (MOR = 1.78 [1.46-2.16]). Among the subgroup of women who conceived spontaneously, endometriosis was found to be associated with placenta praevia, cesarean section, preterm birth and low birth weight. Among the subgroup of women who conceived with the use of assisted reproductive technology, endometriosis was found to be associated with placenta praevia and preterm birth.
LIMITATIONS, REASONS FOR CAUTION
As with any systematic review, the review is limited by the quality of the included studies. The diagnosis for endometriosis and the selection of comparison groups were not uniform across studies. However, the effect of potential misclassification would be bias towards the null hypothesis.
WIDER IMPLICATIONS OF THE FINDINGS
The association between endometriosis with the important and serious pregnancy outcomes observed in our meta-analysis, in particular stillbirth and neonatal death, is concerning and warrants further studies to elucidate the mechanisms for the observed findings.
STUDY FUNDING/COMPETING INTEREST(S)
Dr Shifana Lalani is supported by a Physicians' Services Incorporated Foundation Research Grant, and Dr Innie Chen is supported by a University of Ottawa Clinical Research Chair in Reproductive Population Health and Health Services. Dr Singh declares conflicts of interests with Bayer, Abvie, Allergan and Cooper Surgical. All other authors have no conflicts of interests to declare.
REGISTRATION NUMBER
PROSPERO CRD42015013911.
Topics: Case-Control Studies; Cesarean Section; Diabetes, Gestational; Endometriosis; Female; Humans; Infant, Newborn; Perinatal Death; Placenta Previa; Postpartum Hemorrhage; Pre-Eclampsia; Pregnancy; Premature Birth; Prospective Studies; Retrospective Studies; Stillbirth
PubMed: 30239732
DOI: 10.1093/humrep/dey269 -
Biomedicines Jan 2023Vasa previa carries a high risk of severe fetal morbidity and mortality due to fetal hemorrhage caused by damage to unprotected fetal cord vessels upon membrane rupture.... (Review)
Review
Vasa previa carries a high risk of severe fetal morbidity and mortality due to fetal hemorrhage caused by damage to unprotected fetal cord vessels upon membrane rupture. Vasa previa is generally classified into types I and II. However, some cases are difficult to classify, and some studies have proposed a type III classification. This study aimed to review the current evidence on type III vasa previa. A systematic literature search was conducted, and 11 articles (2011-2022) were included. A systematic review showed that type III vasa previa accounts for 5.7% of vasa previa cases. Thirteen women with type III vasa previa were examined at a patient-level analysis. The median age was 35 (interquartile range [IQR] 31.5-38) years, and approximately 45% were assisted reproductive technology (ART) pregnancies. The median gestational week of delivery was 36 (IQR 34-37) weeks; the antenatal detection rate was 84.6%, and no cases reported neonatal death. The characteristics and obstetric outcomes (rate of ART, antenatal diagnosis, emergent cesarean delivery, gestational age at delivery, and neonatal mortality) were compared between types I and III vasa previa, and all outcomes of interest were similar. The current evidence on type III vasa previa is scanty, and further studies are warranted.
PubMed: 36672661
DOI: 10.3390/biomedicines11010152 -
Acta Obstetricia Et Gynecologica... Aug 2020Low-lying placentas, placenta previa and abnormally invasive placentas are the most frequently occurring placental abnormalities in location and anatomy. These...
Low-lying placentas, placenta previa and abnormally invasive placentas are the most frequently occurring placental abnormalities in location and anatomy. These conditions can have serious consequences for mother and fetus mainly due to excessive blood loss before, during or after delivery. The incidence of such abnormalities is increasing, but treatment options and preventive strategies are limited. Therefore, it is crucial to understand the etiology of placental abnormalities in location and anatomy. Placental formation already starts at implantation and therefore disorders during implantation may cause these abnormalities. Understanding of the normal placental structure and development is essential to comprehend the etiology of placental abnormalities in location and anatomy, to diagnose the affected women and to guide future research for treatment and preventive strategies. We reviewed the literature on the structure and development of the normal placenta and the placental development resulting in low-lying placentas, placenta previa and abnormally invasive placentas.
Topics: Adult; Female; Humans; Placenta Diseases; Pregnancy
PubMed: 32108320
DOI: 10.1111/aogs.13834