-
American Journal of Obstetrics &... Feb 2023This study aimed to investigate the potential role of aspirin in reducing the risk of preeclampsia and adverse maternal and perinatal outcomes in twin pregnancies. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
This study aimed to investigate the potential role of aspirin in reducing the risk of preeclampsia and adverse maternal and perinatal outcomes in twin pregnancies.
DATA SOURCES
Medline, Embase, Google Scholar, Cochrane, and ClinicalTrial.gov databases were searched.
STUDY ELIGIBILITY CRITERIA
The search and selection criteria were restricted to the English language.
METHODS
The primary outcome was the incidence of preeclampsia. The secondary outcomes included gestational hypertension; fetal growth restriction; preterm birth, either spontaneous or iatrogenic, before 34 weeks of gestation; gestational age at birth; neonatal birthweight; and adverse events secondary to the administration of aspirin, including antepartum and postpartum hemorrhage. In addition, subgroup analyses according to chorionicity (dichorionic vs monochorionic), aspirin dose, and gestational age at administration of aspirin (<16 vs ≥16 weeks of gestation) and considering only studies with a daily aspirin dose of ≥100 mg/d were performed. Head-to-head meta-analyses reporting results as summary odds ratios and mean differences were used to analyze categorical and continuous variables, respectively. Quality assessment for randomized controlled trials was independently performed by 2 researchers based on the risk of bias that was assessed using the revised Cochrane risk-of-bias tool for randomized trials. The conclusion of the meta-analysis on the primary outcome was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation.
RESULTS
Overall, 9 studies (2273 twin pregnancies) were included. When considering all studies, the risk of preeclampsia was lower in twin pregnancies treated with aspirin than in those not treated with aspirin (odds ratio, 0.64; 95% confidence interval, 0.48-0.85; P=.003), although there was no significant difference in the risk of gestational hypertension (P=.987), fetal growth restriction (P=.9), or adverse maternal and perinatal events (P=.9) in twin pregnancies treated with aspirin compared with those not treated with aspirin. There was no significant difference in the gestational age at birth (P=.2) and neonatal birthweight (P=.06) between women receiving aspirin and those not receiving aspirin. When considering only studies with an aspirin dose of >100 mg/d, the risk of preeclampsia (odds ratio, 0.45; 95% confidence interval, 0.23-0.86; P=.02) was significantly lower in pregnancies receiving aspirin than in those not receiving aspirin, Conversely, there was no significant difference in the risk of gestational hypertension (P=.20), fetal growth restriction (P=.1), gestational age at birth (P=.06), and neonatal weight (P=.05) between the 2 groups. Furthermore, there was no significant difference in the risk of preeclampsia when considering only studies with an aspirin dose of >80 mg/d (P=.611). The association between the administration of aspirin and preeclampsia persisted when considering an aspirin dose of >100 mg/day or when the medication was started before 16 weeks of gestation. The overall quality of evidence using the Grading of Recommendations, Assessment, Development, and Evaluation assessment was low.
CONCLUSION
The administration of aspirin in women with twin pregnancies reduced the risk of preeclampsia. The findings from this study highlighted the need for randomized controlled trials elucidating the actual role of aspirin in affecting maternal and perinatal outcomes in twin pregnancies.
Topics: Pregnancy; Infant, Newborn; Female; Humans; Pregnancy, Twin; Aspirin; Pre-Eclampsia; Birth Weight; Hypertension, Pregnancy-Induced; Fetal Growth Retardation; Premature Birth
PubMed: 36402356
DOI: 10.1016/j.ajogmf.2022.100803 -
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 -
Cureus Jun 2022Exploration of novel biomarkers has been gaining popularity in preeclampsia, which is currently being diagnosed based on clinical criteria alone. Soluble syndecan-1,... (Review)
Review
Exploration of novel biomarkers has been gaining popularity in preeclampsia, which is currently being diagnosed based on clinical criteria alone. Soluble syndecan-1, released from one of the proteoglycans associated with the syncytiotrophoblastic layer of the placenta, is affected in patients with abnormal placentation. This article is the first systematic literature review that evaluates the relationship between the antepartum serum levels of the syndecan-1 and preeclampsia. Eight studies were selected after screening and quality appraisal, and data were analyzed. The serum concentration of syndecan-1 was found to correlate positively with the gestational age in all pregnancies and negatively with the systolic blood pressure in patients with preeclampsia. Extremely low levels of soluble syndecan-1 may be helpful as a predictor for the development of preeclampsia during gestation.
PubMed: 35836437
DOI: 10.7759/cureus.25794 -
Journal of Minimally Invasive Gynecology Jun 2021The incidence of adnexal masses in pregnancy is 1% to 6%. Although surgery is often indicated, there are no definitive management guidelines. We aimed to investigate the... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
The incidence of adnexal masses in pregnancy is 1% to 6%. Although surgery is often indicated, there are no definitive management guidelines. We aimed to investigate the optimal approach to surgical management of adnexal masses in pregnancy on the basis of a meta-analysis of previous studies.
DATA SOURCES
We performed a systematic review using MEDLINE, Embase, Cochrane Library, and Clinicaltrials.gov from inception to July 17, 2020.
METHODS OF STUDY SELECTION
There were no restrictions on study type, language, or publication date. Comparative and noncomparative retrospective studies that reviewed operative techniques used in surgery of adnexal masses in pregnancy were included. Meta-analyses were performed to assess outcomes. This study was registered in the International Prospective Register of Systematic Reviews (CRD42019129709).
TABULATION, INTEGRATION, AND RESULTS
Comparative studies were identified for laparoscopy vs laparotomy and elective vs emergent surgery (11 and 4, respectively). Elective surgery is defined as a scheduled antepartum procedure. For laparoscopy vs laparotomy, the mean maternal ages and gestational ages at time of surgery were similar (27.8 years vs 27.7 years, p = .85; 16.2 weeks in laparoscopy vs 15.4 weeks in laparotomy, p = .59). Mass size was larger in those undergoing laparotomy (mean 8.8 cm vs 7.8 cm, p = .03). The most common pathologic condition was dermoid cyst (36%), and the risk of discovering a malignant tumor was 1%. Laparoscopy was not associated with a statistically increased risk of spontaneous abortion (SAB) or preterm delivery (PTD) (odds ratio [OR] 1.53; 95% confidence interval [CI], 0.67-3.52; p = .31 and OR 0.95; 95% CI, 0.47-1.89; p = .88, respectively). The mean length of hospital stay was 2.5 days after laparoscopy vs 5.3 days after laparotomy (p <.001). The decrease in estimated blood loss in laparoscopy was not statistically significant (94.0 mL in laparotomy vs 54.0 mL in laparoscopy, p = .06). Operative times were similar in laparoscopy and laparotomy (80.0 minutes vs 72.5 minutes, p = .09). Elective surgery was associated with a decreased risk of PTD (OR 0.13; 95% CI, 0.04-0.48; p = .05). Noncomparative studies were identified for laparoscopy and laparotomy. Laparotomy had more SABs and PTDs than laparoscopy (pooled proportion = 0.02 vs 0.07 and pooled proportion = 0.02 vs 0.14, respectively).
CONCLUSION
Laparoscopy for the surgical management of adnexal masses in pregnancy is associated with shorter length of hospital stay and similar risk of SAB or PTD. Elective surgery is associated with a decreased risk of PTD.
Topics: Adnexal Diseases; Female; Humans; Infant, Newborn; Laparoscopy; Laparotomy; Pregnancy; Retrospective Studies; Treatment Outcome
PubMed: 33515746
DOI: 10.1016/j.jmig.2021.01.020 -
Journal of Diabetes and Its... Apr 2021The antepartum oral glucose tolerance test (OGTT) has re-emerged as associated with risk of diabetes among women with gestational diabetes (GDM). This systematic review... (Meta-Analysis)
Meta-Analysis Review
Association between the antepartum oral glucose tolerance test and the risk of future diabetes mellitus among women with gestational diabetes: A systematic review and meta-analysis.
OBJECTIVES
The antepartum oral glucose tolerance test (OGTT) has re-emerged as associated with risk of diabetes among women with gestational diabetes (GDM). This systematic review summarized evidence on associations between antepartum OGTT and risk of diabetes in GDM (PROSPERO CRD42018100316).
METHODS
MEDLINE, EMBASE, Web of Science, and CENTRAL were searched from January 1, 1982 to February 2020. Studies assessing associations between antepartum OGTT and risk of diabetes among women with GDM were included. Data on study characteristics, participants, OGTT values, and diabetes outcomes were extracted. Estimates on the association between antepartum OGTT and diabetes at follow-up were recorded. Pooled odds ratios for developing diabetes were calculated by study design.
FINDINGS AND CONCLUSIONS
Of 6423 citations, 17 studies were included. Both elevated fasting blood glucose (FBG; OR: 3.62 ([95% CI 1.30, 10.12], I = 36%, p < 0.05)) and 2 h OGTT (OR: 3.96 [1.17, 13.40], I = 87%, p < 0.05) were associated with diabetes. These associations were attenuated (FBG: OR: 1.91 ([95% CI 0.80, 24.54], I = 83%, p = NS) and 1.58 ([95% CI 0.92, 2.74] I = 83%, p = NS) for prospective and retrospective data, respectively; 2 h OGTT: ORa: 1.95 ([95% CI 0.43, 8.93], I = 94%, p = NS)) after adjustments for common confounders. Further research is needed before clinical recommendations can be made.
Topics: Blood Glucose; Diabetes, Gestational; Fasting; Female; Glucose Tolerance Test; Humans; Hyperglycemia; Pregnancy; Prospective Studies; Retrospective Studies; Risk Factors
PubMed: 33349557
DOI: 10.1016/j.jdiacomp.2020.107804 -
International Journal of Dermatology Jun 2024The epidemiological landscape of infantile hemangioma (IH) has been extensively explored through diverse data sources; however, a scarcity of systematically pooled and... (Meta-Analysis)
Meta-Analysis Review
The epidemiological landscape of infantile hemangioma (IH) has been extensively explored through diverse data sources; however, a scarcity of systematically pooled and quantified evidence from comprehensive global studies persists. In this meta-analysis, we systematically review available literature to elucidate the prevalence, distribution of lesions, complications, and risk factors associated with IH. A meticulous search encompassing the Cochrane Library, PubMed, Embase, and Web of Science identified 3206 records, of which 55 studies met the inclusion criteria. We found that the overall prevalence of IH is 2.8% [95% confidence interval (CI): 1.5-4.4%] (31,274,396 infants), and IH was located more frequently in the head and neck with a prevalence of 47.4% (95% CI: 39.5-55.4%). The overall prevalence of complications of IH is 24.3% (95% CI: 18.6-30.5%), ulceration is 16.0% (95% CI: 10.4-21.2%), bleeding is 5.6% (95% CI: 3.3-8.5%), visual impairment is 5.6% (95% CI: 3.0-8.9%), infection is 2.8% (95% CI: 1.5-4.8%), subglottic obstruction is 1.5% (95% CI: 0.5-3.0%), respectively. Through 27 studies, we have evaluated 35 factors encompassing perinatal factors, socioeconomic factors, maternal complications, drug factors, and antepartum procedures, and identified 18 risk factors that increase the prevalence of IH. These findings can greatly assist clinicians and family members in effectively evaluating the risk of IH, and determining whether pregnant women should undergo intensified monitoring or preventive measures.
Topics: Humans; Risk Factors; Prevalence; Infant; Skin Neoplasms; Hemangioma; Pregnancy; Vision Disorders; Female; Hemorrhage; Ulcer; Infections; Head and Neck Neoplasms; Airway Obstruction
PubMed: 38329175
DOI: 10.1111/ijd.17062 -
International Journal of Health Sciences 2020The aim of this systematic review and meta-analysis was to estimate the pooled magnitude of birth asphyxia and its determinants in Ethiopia. (Review)
Review
OBJECTIVE
The aim of this systematic review and meta-analysis was to estimate the pooled magnitude of birth asphyxia and its determinants in Ethiopia.
METHODS
The databases, including PubMed, Medline, CINAHL, EMBASE, and other relevant sources, were used to search relevant articles. Both published and unpublished studies, written in English and carried out in Ethiopia, were included in the study. Quality of evidence was assessed by the relevant of the Joanna Briggs Institute tool. RevMan v5.3 statistical software was used to undertake the meta-analysis using a Mantel-Haenszel random-effects model. Heterogeneity was evaluated using the Cochran Q test, and I2 statistics was considered to assess its level. The outcome was measured using a 95% confidence interval (CI).
RESULTS
The pooled prevalence of birth asphyxia was 22.8% (95% CI: 13-36.8%]. Illiterate mothers (adjusted odds ratio [AOR]; 1.96, 95% CI: 1.44-2.67), antepartum hemorrhage (APH) (AOR; 3.43, 95% CI: 1.74-6.77), cesarean section (AOR; 3.66, 95% CI: 1.35-9.91), instrumental delivery (AOR; 2.74, 95% CI: 1.48-5.08), duration of labor (AOR; 3.09, 95% CI: 1.60-5.99), pregnancy induced hypertension (AOR; 4.35, 95% CI: 2.98-6.36), induction of labor (AOR; 3.69, 95% CI: 2.26-6.01), parity (AOR; 1.29, 95% CI: 1.03-1.62), low birth weight (LBW) (AOR; 5.17, 95% CI: 2.62-10.22), preterm (AOR; 3.98, 95% CI: 3.00-5.29), non-cephalic presentation (AOR; 4.33, 95% CI: 1.97-9.51), and meconium staining (AOR; 4.59, 95% CI: 1.40-15.08) were significantly associated with birth asphyxia.
CONCLUSION
The magnitude of birth asphyxia was very high. Maternal education, APH, mode of delivery, prolonged labor, induction, LBW, preterm, meconium-staining, and non-cephalic presentation were determinants of birth asphyxia. Hence, to reduce birth asphyxia and associated neonatal mortality, attention should be directed to improve the quality of intrapartum service and timely communication between the delivery team. In addition, intervention strategies aimed at reducing birth asphyxia should target the identified determinants.
PubMed: 32082102
DOI: No ID Found -
American Journal of Obstetrics &... Aug 2020To evaluate reported outcomes of published studies on the diagnosis and management of vasa previa in pregnancy. (Review)
Review
OBJECTIVE
To evaluate reported outcomes of published studies on the diagnosis and management of vasa previa in pregnancy.
MATERIALS AND METHODS
Databases such as MEDLINE, Embase, Cochrane, PubMed, and ClinicalTrials.gov were searched up to March 2018 for all published studies on vasa previa using combinations of the following medical subject headings and key words: vasa previa, placenta previa, low-lying placenta, succenturiate lobe or placenta, bilobed or bilobate placenta, and velamentous insertion. All original human research that described maternal, obstetric, placental, fetal or neonatal outcomes relating to pregnancies with vasa previa were included for analysis. Title and abstract screening and data extraction was conducted independently and in duplicate by 2 reviewers for all studies until total agreement for eligibility was achieved. Data extraction was also conducted in duplicate in approximately 50% of studies reviewed.
RESULTS
A total of 160 published studies (1004 pregnancies) were included. There was a wide range of reported outcomes, many of which were sparingly reported. The most commonly reported maternal outcomes included mode of delivery, presence of antepartum hemorrhage, time of diagnosis, and rupture of membranes. The presence of known risk factors for vasa previa such as a low-lying placenta, succenturiate or bilobed placenta, and (velamentous) cord insertion was incorrectly reported as "outcomes" in many studies. The most commonly reported fetal/neonatal outcomes included fetal heart rate, gestational age at delivery, birthweight, Apgar score, presence of neonatal anemia, cord blood gas measurements, need for blood transfusion, and death. Of note, only 3 studies reported outcomes related to life impact, maternal social and emotional functioning, perceived delivery of care, or resource utilization.
CONCLUSION
Despite the profound effect the diagnosis of vasa previa has on pregnant women, families, and healthcare systems, studies on vasa previa seldom report outcomes related to life impact and resource utilization. There is a need for the development of a core outcome set-a minimum standard set of outcomes deemed important by pregnant women and other stakeholders involved in their care-to standardize outcome reporting in future studies on vasa previa.
Topics: Female; Gestational Age; Humans; Infant, Newborn; Patient Reported Outcome Measures; Placenta; Placenta Previa; Pregnancy; Vasa Previa
PubMed: 33345867
DOI: 10.1016/j.ajogmf.2020.100116 -
PloS One 2021A number of primary studies in Ethiopia address the prevalence of birth asphyxia and the factors associated with it. However, variations were seen among those studies.... (Meta-Analysis)
Meta-Analysis
BACKGROUND
A number of primary studies in Ethiopia address the prevalence of birth asphyxia and the factors associated with it. However, variations were seen among those studies. The main aim of this systematic review and meta-analysis was carried out to estimate the pooled prevalence and explore the factors that contribute to birth asphyxia in Ethiopia.
METHODS
Different search engines were used to search online databases. The databases include PubMed, HINARI, Cochrane Library and Google Scholar. Relevant grey literature was obtained through online searches. The funnel plot and Egger's regression test were used to see publication bias, and the I-squared was applied to check the heterogeneity of the studies. Cross-sectional, case-control and cohort studies that were conducted in Ethiopia were also be included. The Joanna Briggs Institute checklist was used to assess the quality of the studies and was included in this systematic review. Data entry and statistical analysis were carried out using RevMan 5.4 software and Stata 14.
RESULT
After reviewing 1,125 studies, 26 studies fulfilling the inclusion criteria were included in the meta-analysis. The pooled prevalence of birth asphyxia in Ethiopia was 19.3%. In the Ethiopian context, the following risk factors were identified: Antepartum hemorrhage(OR: 4.7; 95% CI: 3.5, 6.1), premature rupture of membrane(OR: 4.0; 95% CI: 12.4, 6.6), primiparas(OR: 2.8; 95% CI: 1.9, 4.1), prolonged labor(OR: 4.2; 95% CI: 2.8, 6.6), maternal anaemia(OR: 5.1; 95% CI: 2.59, 9.94), low birth weight(OR = 5.6; 95%CI: 4.7,6.7), meconium stained amniotic fluid(OR: 5.6; 95% CI: 4.1, 7.5), abnormal presentation(OR = 5.7; 95% CI: 3.8, 8.3), preterm birth(OR = 4.1; 95% CI: 2.9, 5.8), residing in a rural area (OR: 2.7; 95% CI: 2.0, 3.5), caesarean delivery(OR = 4.4; 95% CI:3.1, 6.2), operative vaginal delivery(OR: 4.9; 95% CI: 3.5, 6.7), preeclampsia(OR = 3.9; 95% CI: 2.1, 7.4), tight nuchal cord OR: 3.43; 95% CI: 2.1, 5.6), chronic hypertension(OR = 2.5; 95% CI: 1.7, 3.8), and unable to write and read (OR = 4.2;95%CI: 1.7, 10.6).
CONCLUSION
According to the findings of this study, birth asphyxia is an unresolved public health problem in the Ethiopia. Therefore, the concerned body needs to pay attention to the above risk factors in order to decrease the country's birth asphyxia.
REVIEW REGISTRATION
PROSPERO International prospective register of systematic reviews (CRD42020165283).
Topics: Asphyxia Neonatorum; Ethiopia; Female; Humans; Infant, Newborn; Pregnancy; Pregnancy Complications; Premature Birth; Risk Factors
PubMed: 34351953
DOI: 10.1371/journal.pone.0255488 -
BMC Pregnancy and Childbirth Sep 2020Globally, complications of preterm birth are among the most common cause of neonatal mortality. In Ethiopia, the neonatal mortality reduction is not worthy of attention.... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Globally, complications of preterm birth are among the most common cause of neonatal mortality. In Ethiopia, the neonatal mortality reduction is not worthy of attention. Hence, this study reviewed the prevalence of preterm birth and factors associated with preterm birth in Ethiopia.
METHODS
The review protocol of this study has been registered in PROSPERO (CRD42017077356). The PRISMA guideline was followed for this review. Studies that assessed the prevalence and/or associated factors of preterm birth in Ethiopia and published from Jan 01, 2009 to Dec 31, 2019 were considered. Studies were searched from the PubMed and Science Direct among medical electronic databases and Google Scholar. Random-effects model was used for detected heterogeneity among studies. Publication bias and sensitivity analysis were assessed. Pooled estimates with its 95% confidence interval were reported using forest plots. The quality of evidence from the review was assessed using GRADE approach.
RESULTS
Twenty-two studies involving a total of 12,279 participants were included. The overall pooled prevalence of preterm birth in Ethiopia was 10.48% (95% CI: 7.98-12.99). Pooled odds ratio showed rural residence (AOR = 2.34, 95% CI: 1.35-4.05), being anemic (AOR = 2.59, 95% CI: 1.85-3.64), < 4 antenatal care visits (AOR = 2.34, 95%CI: 1.73-3.33), pregnancy induced hypertension (AOR = 3.49, 95% CI: 2.45-4.97), prelabor rapture of membrane (AOR = 4.42, 95% CI: 2.28-8.57), antepartum hemorrhage (AOR = 5.02, 95% CI: 2.90-8.68), multiple pregnancies (AOR = 3.89, 95% CI: 2.52-5.99), past adverse birth outcomes (AOR = 3.24, 95% CI: 2.53-4.15) and chronic illness (AOR = 4.89, 95%CI: 3.12-7.66) were associated with increased likelihood of preterm birth. Further, support during pregnancy was associated with reduced occurrence of preterm birth.
CONCLUSION
The pooled national level prevalence of preterm birth in Ethiopia is high. Socio demographic, nutritional, health care, obstetric and gynecologic, chronic illness and medical conditions, behavioral and lifestyle factors are the major associated factors of preterm birth in Ethiopia. This evidence is graded as low grade. Thus, efforts should be intensified to address reported risk factors to relieve the burden of preterm birth in the study setting, Ethiopia.
Topics: Ethiopia; Humans; Infant, Newborn; Premature Birth
PubMed: 32993555
DOI: 10.1186/s12884-020-03271-6