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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 -
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 -
Schizophrenia Research Dec 2023Schizophrenia is a severe mental illness that affects a significant proportion of the global population, particularly those of childbearing age. Several studies have... (Meta-Analysis)
Meta-Analysis Review
INTRODUCTION
Schizophrenia is a severe mental illness that affects a significant proportion of the global population, particularly those of childbearing age. Several studies have attempted to find an association between schizophrenia and obstetric complications, with varying results.
OBJECTIVE
The primary objective of this systematic review and meta-analyses was to summarize the relationship between maternal schizophrenia and perinatal pregnancy outcomes.
DATA SOURCES
PubMed, Web of Science and Ovid EMBASE were searched from January 2001 to September 2022 using keywords related to pregnancy, women, schizophrenia.
STUDY SELECTION
A total of 23 independent studies across 21,253 individuals with schizophrenia were identified and included in the analysis.
DATA EXTRACTION
The following data were extracted: author, year of publication, country/continent of data collection, study design, demographic characteristics, diagnoses criteria, related complications. Data were analyzed using random-effects pairwise meta-analysis and were reported as prevalence and odd ratios (OR). Statistical heterogeneity was quantified with the I statistic.
RESULTS
The prevalence of adverse perinatal pregnancy outcomes was represented in descending order: cesarean section (26.0 %); labor induction (24.0 %); small for gestational age (10.5 %); gestational diabetes mellitus (9.2 %); preterm birth (9.1 %); low birth weight (7.8 %); preterm rupture of membranes (6.1 %); 1-Minute Apgar Score < 7 (5.6 %); large for gestational age (5.5 %); birth defect (5.4 %); antepartum hemorrhage (4.4 %);preeclampsia/eclampsia (4.8 %); postpartum hemorrhage (3.9 %); 5-Minute Apgar Score < 7 (3.6 %); gestational hypertension (3.3 %); placental abruption (1.0 %); placenta previa (0.6 %); thromboembolic disease (0.4 %); neonatal mortality (0.3 %) (P ≤ 0.05). There was a higher risk of adverse outcomes including gestational diabetes mellitus, preeclampsia/eclampsia, placental abruption, thromboembolic disease, preterm birth, birth defect, 1-Minute Apgar score < 7, small for gestational age, low birth weight and neonatal mortality compared with non-schizophrenia population (P ≤ 0.05).
CONCLUSIONS
Women with schizophrenia are at higher risk of adverse perinatal pregnancy outcomes. It is imperative that research efforts continue to focus on the reproductive safety of women with schizophrenia during their childbearing years.
Topics: Pregnancy; Female; Infant, Newborn; Humans; Pregnancy Outcome; Premature Birth; Diabetes, Gestational; Abruptio Placentae; Cesarean Section; Pre-Eclampsia; Eclampsia; Schizophrenia; Placenta
PubMed: 37979419
DOI: 10.1016/j.schres.2023.11.001 -
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 -
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 -
Birth (Berkeley, Calif.) Jun 2022Studies have suggested that cesarean birth in pregnant women with COVID-19 may decrease maternal adverse events and perinatal transmission. This systematic review aimed... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Studies have suggested that cesarean birth in pregnant women with COVID-19 may decrease maternal adverse events and perinatal transmission. This systematic review aimed to evaluate variations in clinical presentation, laboratory findings, and maternal/neonatal outcomes in COVID-19 patients who delivered vaginally versus via cesarean.
METHODS
A comprehensive search following PRISMA guidelines was performed for studies published up to May 23, 2020, using PubMed, Web of Science, Scopus, Embase, Cochrane, Science Direct, and clinicaltrials.gov. Original retrospective and prospective studies, case reports, or case series with sufficient data for estimating the association of COVID-19 with different pregnancy outcomes with no language restriction and published in peer-reviewed journals were included. Pooled mean and arcsine transformation proportions were applied. Next, a two-arm meta-analysis was performed comparing the perinatal outcomes between the study groups.
RESULTS
Forty-two studies with a total of 602 pregnant women with COVID-19 were included. The mean age was 31.8 years. Subgroup analysis showed that Americans had the lowest gestational age (mean = 32.7, 95%CI = 27.0-38.4, P < 0.001) and the highest incidence of maternal ICU admission (95%CI = 0.45%-2.20, P < 0.001) of all nationalities in the study. There was no significant difference in perinatal complications, premature rupture of membrane, placenta previa/accreta, or gestational hypertension/pre-eclampsia between women who delivered vaginally versus by cesarean. Importantly, there were also no significant differences in maternal or neonatal outcomes.
CONCLUSION
Vaginal delivery was not associated with worse maternal or neonatal outcomes when compared with cesarean. The decision to pursue a cesarean birth should be based on standard indications, not COVID-19 status.
Topics: Adult; COVID-19; Female; Humans; Infant, Newborn; Infectious Disease Transmission, Vertical; Pregnancy; Pregnancy Outcome; Pregnant Women; Premature Birth; Prospective Studies; Retrospective Studies; SARS-CoV-2
PubMed: 34997608
DOI: 10.1111/birt.12609 -
Journal of Global Health Jun 2024As birth policy can affect maternal and infant health, we sought to identify whether and how the introduction of the two-child policy might have affected the prevalence... (Meta-Analysis)
Meta-Analysis
BACKGROUND
As birth policy can affect maternal and infant health, we sought to identify whether and how the introduction of the two-child policy might have affected the prevalence of placenta previa in pregnant women in mainland China.
METHODS
In this update meta-analysis and systematic review, we searched PubMed, Web of Science, the Cochrane Library, Weipu, Wanfang, and the China National Knowledge Infrastructure (CNKI) databases for studies evaluating the prevalence of placenta previa in China published between the inception of each database and March 2024, with no restrictions. Two investigators independently extracted the data from each included study. We then combined the prevalence of placenta previa using random-effects models.
RESULTS
We included 128 studies in our analysis, 48 more than in our previous review. The prevalence of placenta previa among Chinese pregnant women was 1.44% (95% confidence interval (CI) = 1.32, 1.56). After the implementation of the two-child policy, the prevalence increased significantly, from 1.25% (95% CI = 1.16, 1.34) to 4.12% (95% CI = 3.33, 4.91).
CONCLUSIONS
The prevalence of placenta previa increased significantly from the one-child policy period to the two-child policy period among mainland Chinese pregnant women, with varying trends across regions. This change requires the attention of health officials and timely adjustment of resource allocation policies.
REGISTRATION
PROSPERO: CRD42021262309.
Topics: Humans; Pregnancy; China; Female; Placenta Previa; Prevalence; Delivery, Obstetric
PubMed: 38867677
DOI: 10.7189/jogh.14.04108 -
Minerva Obstetrics and Gynecology Oct 2022To explore the role of balloon tamponade insertion in pregnancies complicated by placenta previa. (Meta-Analysis)
Meta-Analysis
INTRODUCTION
To explore the role of balloon tamponade insertion in pregnancies complicated by placenta previa.
EVIDENCE ACQUISITION
Medline, Embase and ClinicalTrials.gov databases were searched electronically on October 17. Inclusion criteria were women with placenta previa undergoing, compared to those not undergoing, balloon tamponade insertion at the time of the cesarean section (CS). The outcomes observed were total, intra- and post-operative estimated blood loss (EBL), need for blood transfusion, admission to intensive care unit (ICU), hysterectomy and additional surgical or medical procedures to achieve hemostasis. Results were reported as pooled odd ratios (OR) or mean difference (MD) according to the outcome investigated.
EVIDENCE SYNTHESIS
Four studies (593 women) were included. Total EBL was significantly lower in women undergoing balloon tamponade insertion during CS compared to controls (MD: -556.3, 95% CI -496 to -617.0, P=0.001). Likewise, women undergoing balloon tamponade insertion had significantly lower intra- (MD: -699.8, 95% CI -766.1 to -633.5, P=0.001) and post-operative (MD: -1162 mL (95% CI -1211.1 to -1134.4, P<0.001) compared to women who did undergo such procedure. Furthermore, women undergoing balloon tamponade insertion had a significantly lower risk of requiring additional surgical (OR: 0.16, 95% CI 0.1-0.5, I=0%; P=0.001) or medical (OR: 0.02, 95% CI 0.003-0.1, I=0; P=0.001) procedures to achieve hemostasis. Conversely, there was no significant difference in either the need for blood transfusion (P=0.071), admission to ICU (P=0.459) or need for hysterectomy (P=0.312) between women undergoing, compared to those not undergoing, balloon tamponade insertion during CS for placenta previa.
CONCLUSIONS
Elective balloon tamponade insertion at the time of CS for placenta previa seems to be associated with a lower EBL and a reduced risk of additional medical and surgical procedures to control hemostasis. Large and adequately powered randomized controlled trials are needed to validate these results and introduce elective balloon tamponade insertion at the time of CS for placenta previa in clinical practice.
Topics: Female; Pregnancy; Humans; Male; Placenta Previa; Uterine Balloon Tamponade; Cesarean Section; Postpartum Hemorrhage; Hysterectomy; Postoperative Hemorrhage
PubMed: 35238196
DOI: 10.23736/S2724-606X.22.05055-2 -
Frontiers in Endocrinology 2022To investigate the risk of preterm birth in women with a placenta previa or a low-lying placenta for different cut-offs of gestational age and to evaluate preventive... (Meta-Analysis)
Meta-Analysis
OBJECTIVE
To investigate the risk of preterm birth in women with a placenta previa or a low-lying placenta for different cut-offs of gestational age and to evaluate preventive interventions.
SEARCH AND METHODS
MEDLINE, EMBASE, CENTRAL, Web of Science, WHO-ICTRP and clinicaltrials.gov were searched until December 2021. Randomized controlled trials, cohort studies and case-control studies assessing preterm birth in women with placenta previa or low-lying placenta with a placental edge within 2 cm of the internal os in the second or third trimester were eligible for inclusion. Pooled proportions and odds ratios for the risk of preterm birth before 37, 34, 32 and 28 weeks of gestation were calculated. Additionally, the results of the evaluation of preventive interventions for preterm birth in these women are described.
RESULTS
In total, 34 studies were included, 24 reporting on preterm birth and 9 on preventive interventions. The pooled proportions were 46% (95% CI [39 - 53%]), 17% (95% CI [11 - 25%]), 10% (95% CI [7 - 13%]) and 2% (95% CI [1 - 3%]), regarding preterm birth <37, <34, <32 and <28 weeks in women with placenta previa. For low-lying placentas the risk of preterm birth was 30% (95% CI [19 - 43%]) and 1% (95% CI [0 - 6%]) before 37 and 34 weeks, respectively. Women with a placenta previa were more likely to have a preterm birth compared to women with a low-lying placenta or women without a placenta previa for all gestational ages. The studies about preventive interventions all showed potential prolongation of pregnancy with the use of intramuscular progesterone, intramuscular progesterone + cerclage or pessary.
CONCLUSIONS
Both women with a placenta previa and a low-lying placenta have an increased risk of preterm birth. This increased risk is consistent across all severities of preterm birth between 28-37 weeks of gestation. Women with placenta previa have a higher risk of preterm birth than women with a low-lying placenta have. Cervical cerclage, pessary and intramuscular progesterone all might have benefit for both women with placenta previa and low-lying placenta, but data in this population are lacking and inconsistent, so that solid conclusions about their effectiveness cannot be drawn.
SYSTEMATIC REVIEW REGISTRATION
PROSPERO https://www.crd.york.ac.uk/prospero/, identifier CRD42019123675.
Topics: Cervix Uteri; Female; Humans; Infant, Newborn; Placenta; Placenta Previa; Pregnancy; Premature Birth; Progesterone
PubMed: 36120450
DOI: 10.3389/fendo.2022.921220