Efficacy of probiotic supplement for gestational diabetes mellitus: a systematic review and meta-analysis

Background: Probiotic supplement might be beneficial for gestational diabetes mellitus. However, the results remained controversial. We conducted a systematic review and meta-analysis to explore the efficacy of probiotic supplement in gestational diabetes mellitus.

Methods: PubMed, Embase, Web of science, EBSCO, and Cochrane Library databases were systematically searched. Randomized controlled trials (RCTs) assessing the effect of probiotic supplement in gestational diabetes mellitus were included. Two investigators independently searched articles, extracted data, and assessed the quality of included studies. The primary outcome were fasting serum insulin and fasting plasma glucose. Meta-analysis was performed using the fixed-effect or random-effect model.

Results: Six RCTs involving 830 patients were included in the meta-analysis. Overall, compared with control intervention in gestational diabetes mellitus, probiotic supplementation intervention was found to significantly reduce fasting serum insulin (Std. mean difference?=??0.95; 95% CI?=??1.73 to ?0.17; p?p?=?.02), but showed no substantial impact on fasting plasma glucose (Std. mean difference =??0.49; 95% CI?=??1.05–0.08; p?=?.09), gestational age (Std. mean difference?=?0.07; 95% CI?=??0.20–0.34; p?=?.63), and gestational weight (Std. mean difference?=??0.11; 95% CI?=??0.38–0.16; p?=?.43).

Conclusions: Compared with control intervention in gestational diabetes mellitus, probiotic supplementation was found to significantly reduce insulin resistance (HOMA-IR) and fasting serum insulin, but had no substantial influence on fasting plasma glucose, gestational age and gestational weight.     

Association between intrahepatic cholestasis of pregnancy and risk of gestational diabetes and preeclampsia: a systematic review and meta-analysis

ABSTRACT

Objective

To investigate the association between intrahepatic cholestasis of pregnancy (ICP) and the risk of gestational diabetes mellitus (GDM) and preeclampsia via meta-analysis.     

The effects of gene polymorphisms in angiotensin II receptors on pregnancy-induced hypertension and preeclampsia: a systematic review and meta-analysis

Background: To assess whether the polymorphisms of angiotensin II type 1 and type 2 receptors (AT1R, AT2R) are associated with pregnancy-induced hypertension (PIH) and preeclampsia. Methods: Studies were searched from PubMed, ISI Web of Science and HuGE Navigator. Results: The A1166C polymorphism of AT1R, A1675G and C3123A polymorphisms of AT2R were analyzed. Significant association was found in recessive model (OR?=?1.581, 95% confidence interval (CI): 1.054–2.371) and co-dominant (GG versus AG) model (OR?=?1.900, 95%CI: 1.001–3.604) between the A1675G polymorphism and preeclampsia. No association was found between the other polymorphisms and PIH or preeclampsia. Conclusions: The A1675G polymorphism might be associated with preeclampsia, but the A1166C and C3123A polymorphisms had no effect on PIH or preeclampsia.     

The association between preeclampsia and the severity of gestational diabetes: the impact of glycemic control

OBJECTIVES: We sought to determine if the rate of preeclampsia is related to the severity of gestational diabetes mellitus (GDM), and if it can be decreased by optimizing glycemic control. STUDY DESIGN: A retrospective analysis of prospectively collective data of 1813 patients with GDM was performed to determine the rate of preeclampsia. Patients were stratified after treatment was begun by level of glycemic control (well controlled was defined as mean blood glucose <95 mg/dL). The extent of hyperglycemia was analyzed by the level of the abnormality in the oral GTT and by the degree of abnormality of daily glucose control after treatment has begun. Severity of GDM was categorized using fasting plasma glucose (FPG) on a 3-hour oral GTT by 10 mg/dL increments. RESULTS: Overall, preeclampsia was diagnosed in 9.6% (174/1813) of diabetic patients. The GDM subjects who developed preeclampsia were significantly younger, had a higher nulliparity rate, were more obese, and gained significantly more weight during pregnancy. However, no difference was found in glycemic profile characteristics between the 2 groups. A comparison between patients with FPG <105 and FPG >105 revealed that the rate of preeclampsia increased significantly, 7.8% vs 13.8%, (O.R 1.81, 95%CI 1.3-2.51). For GDM patients with only mild hyperglycemia (FPG <105 mg/dL), no significant difference was found in the rate of preeclampsia. Preeclampsia rate was further evaluated in relation to level of glycemic control; for the well-controlled patients (mean blood glucose [MBG] <95 mg/dL, n=994), similar rates of preeclampsia were found between each category of FPG severity. In contrast, in poorly controlled patients (MBG >95 mg/dL, n=819), a comparison between severity threshold of FPG <115 and FPG >115 revealed that the preeclampsia rate was 9.8% vs 18% (O.R 2.56, 95%C.I. 1.5-4.3). In a logistic regression model, only prepregnancy BMI (O.R 2.3, 95%CI 1.16-2.30) and severity of GDM (O.R 1.7, 95%CI 1.21-2.38) were independently and significantly associated with an increased risk of preeclampsia. CONCLUSION: The rate of preeclampsia is influenced by the severity of GDM and prepregnancy BMI. Optimizing glucose control during pregnancy may decrease the rate of preeclampsia, even in those with a greater severity of GDM.     

Carbetocin for the prevention of postpartum hemorrhage: a systematic review and meta-analysis of randomized controlled trials

Objective: To compare the efficacy and safety profile of carbetocin with other uterotonic agents in preventing postpartum hemorrhage.

Methods: PubMed, Web of Science, Scopus and EBSCOhost were searched for relevant randomized controlled trials published until September 2013.

Results: Carbetocin was associated with a significantly reduced need for additional uterotonic agents (RR?=?0.68, 95% CI: 0.55–0.84, I^2?=?4%) compared with oxytocin in women following cesarean delivery. However, with respect to postpartum hemorrhage, severe postpartum hemorrhage, mean estimated blood loss and adverse effects, our analysis failed to detect a significant difference. Studies comparing carbetocin with syntometrine in women undergoing vaginal delivery demonstrated no statistical difference in terms of risk of postpartum hemorrhage, severe postpartum hemorrhage or the need for additional uterotonic agents, but the risk of adverse effect was significantly lower in the carbetocin group.

Conclusions: Carbetocin has been associated with a similar low incidence of adverse effects to oxytocin and at least as effective as syntometrine and may become an alternative uterotonic agent for the prevention of postpartum hemorrhage. Further studies should be conducted to determine the safety and efficacy profile of carbetocin in women with cardiac disorders and to analyze the cost-effectiveness and minimum effective dose of carbetocin.     

Endometriosis and gestational diabetes mellitus risk: a systematic review and meta-analysis

Objective: To perform a systematic review and meta-analysis regarding endometriosis and the risk of gestational diabetes mellitus (GDM).

Methods: We carried out a search of the following databases: Medline, Embase, Web of Science, Cochrane Library, Scopus, Scielo, Clinicaltrials.gov, the UK Clinical Trials Gateway, and the Australian New Zealand Clinical Trials Registry, from inception through April 28 2017, without language restrictions, in order to evaluate the effect of endometriosis over GDM risk, in women with and without endometriosis. Odds ratios (ORs) and their 95% confidence intervals (CIs) or mean differences (MDs) were calculated as effects. Methodological quality of evidence was assessed with the Newcastle–Ottawa Scale, and heterogeneity among studies with the I² statistic. Random-effects models were used for meta-analyses, and publication bias was assessed with Egger’s test.

Results: We identified 12 studies (10 cohort and two case control studies) with a total of 48,762 pregnancies, including 3,461 with endometriosis. Endometriosis had no significant effect on GDM risk (OR =1.14; 95% CI: 0.86, 1.51; p?=?.35, I²?=?56%, Egger’s test p?=?.45). Secondary outcomes (gestational age at delivery, birthweight, and Neonatal Intensive Care Unit admission) were statistically similar in women with and without endometriosis.

Conclusions: Better-designed studies are needed to confirm our results.     

The efficacy of myo-inositol supplementation to prevent gestational diabetes onset: a meta-analysis of randomized controlled trials

Introduction: The efficacy of myo-inositol supplementation to prevent gestational diabetes onset remains controversial. We conducted a systematic review and meta-analysis to explore the influence of myo-inositol supplementation on the incidence of gestational diabetes.

Methods: We search PubMed, Embase, Web of science, EBSCO, and Cochrane Library databases through November 2017 for randomized controlled trials (RCTs) assessing the effect of myo-inositol supplementation on gestational diabetes onset. This meta-analysis is performed using the random-effect model.

Results: Five randomized controlled trials (RCTs) are included in the meta-analysis. Compared with control group in pregnant women, myo-inositol supplementation is associated with significantly reduced incidence of gestational diabetes (risk ratio (RR)?=?0.43; 95%CI?=?0.21–0.89; p?=?.02), and preterm delivery (RR?=?0.36; 95%CI?=?0.17–0.73; p?=?.005), but has no substantial impact on 2-h glucose oral glucose tolerance test (OGTT) (mean difference (MD)?=??6.90; 95%CI?=??15.07 to 1.27; p?=?.10), gestational age at birth (MD?=?0.74; 95%CI?=??1.06 to 2.54; p?=?.42), birth weight (MD?=??5.50; 95%CI?=??116.99 to 105.99; p?=?.92), and macrosomia (RR?=?0.65; 95%CI?=?0.20–2.11; p?=?.47).

Conclusions: Myo-inositol supplementation has some ability to reduce the incidence of gestational diabetes and preterm delivery in pregnant women.     

Maternal anemia during pregnancy and small for gestational age: a systematic review and meta-analysis

Objective: Anemia is a major public health and nutritional problem in the world. Studies have reported the relationship between anemia during pregnancy and small for gestational age (SGA). Therefore, the present systematic review and meta-analysis was conducted to determine the relationship between maternal anemia during pregnancy and SGA.

Method: This meta-analysis was conducted without time limit until April 2017 based on the PRISMA protocol. Several international databases including Cochrane, Scopus, Web of Science (ISI), Pubmed, Embase, and Google Scholar search engine were searched independently by two researchers. The keywords include: anemia, pregnant women, gestational age, and pregnancy. The relative risk (RR) and 95% confidence interval were estimated regarding to the significance of the I² index based on the random effects model. Data were analyzed using Comprehensive Meta-Analysis Software version 2.

Results: Ten studies with a sample size including 620 080 pregnant women entered the meta-analysis process. The overall relationship between maternal anemia during pregnancy and SGA was not significant (RR?=?1.11 [95%CI: 0.99–1.24, p?=?.074]). The relationship between anemia during pregnancy and SGA based on pregnancy trimester showed that maternal anemia was significant in the first trimester, (RR?=?1.11 [95%CI: 1–1.22, p?=?.044]), but this relationship was not significant in the second trimester (RR?=?1.11 [95%CI: 0.85–1.18, p?=?.91]).

Conclusions: Maternal anemia in the first trimester of pregnancy can be considered as a risk factor for negative pregnancy outcomes (SGA).     

Effect of folic acid supplementation during pregnancy on gestational hypertension/preeclampsia: A systematic review and meta-analysis

Objective: To evaluate the effect of folic acid supplementation during pregnancy on the risk of gestational hypertension/preeclampsia. Methods: A systematic review and meta-analysis were conducted. Medline, Embase, Scopus, and the Web of Science were searched from inception to December 2014. Results: Out of 1224 potentially relevant studies, 13 studies met our inclusion criteria (2 randomized controlled trials (RCTs), 10 cohort studies, and 1 case–control study). The pooled relative risk (RR) and 95% confidence interval (CI) of the two RCTs were 0.62 (0.45–0.87) in the trial arm as compared with the placebo arm. The pooled RR was 0.92 (95% CI: 0.79–1.08) for nine cohort studies with available data on folic acid supplementation in pregnancy and gestational hypertension/preeclampsia. Pooled RR was 0.88 (95% CI: 0.76–1.02) for eight cohort studies with available data on folic acid supplementation and preeclampsia. Conclusion: Whether folic acid supplementation in pregnancy can prevent the occurrence of gestational hypertension/preeclampsia remains uncertain.     

The association between hyaline membrane disease and preeclampsia

OBJECTIVE: The purpose of this study was to determine whether hyaline membrane disease is increased in newborn infants who are born to women with preeclampsia compared with control subjects. STUDY DESIGN: This was a historic cohort study of deliveries between 24 and 37 weeks of gestation at the Medical University of South Carolina from 1996 through 2002. Singleton infants who were born to women with preeclampsia were compared with nonpreeclamptic control subjects. The incidence of hyaline membrane disease was compared by chi 2 analysis and Fisher exact test, with significance at a probability value of <.05. Logistic regression analysis was performed to address potential confounders. RESULTS: There were 814 women with preeclampsia and 3021 control subjects. When we controlled for confounding factors, there was a significant increase in the incidence of hyaline membrane disease in the preeclamptic group overall (odds ratio, 1.35; 95% CI, 1.03-1.78). The risk was more pronounced in neonates who were born at 32 weeks of gestation (odds ratio, 1.93; 95% CI, 1.28-2.91). CONCLUSION: The risk of hyaline membrane disease in neonates at < 32 weeks of gestation is increased in patients with preeclampsia. This supports the contention that fetal lung maturity is not accelerated in preeclampsia.     

The association between the environmental endocrine disruptor bisphenol A and polycystic ovary syndrome: a systematic review and meta-analysis

Objective: To investigate the association between bisphenol A (BPA) and polycystic ovary syndrome (PCOS).

Methods: A systematic review and meta-analysis using STATA software for observational studies.

Results: Nine studies involving 493 PCOS patients and 440 controls were included in this review. The meta-analysis demonstrated that PCOS patients had significantly higher BPA levels compared with control groups (standardized mean difference (SMD): 2.437, 95% confidence interval (CI): (1.265, 3.609), p?p?p?=?.002), high quality (SMD: 0.624, 95% CI: (0.391, 0.856), p?p?=?.008).

Conclusions: Serum BPA may be positively associated with women with PCOS and BPA might be involved in the insulin-resistance and hyperandrogenism of PCOS. More evidence from high quality studies, advanced detection methods, and larger cohorts for observational trials are needed to further confirm the association between BPA and PCOS.     

Lack of association between matrix metalloproteinase-9 gene-1562C/T polymorphism and preeclampsia: a meta-analysis

Studies investigating the association between matrix metalloproteinases (MMPs) gene polymorphisms and preeclampsia (PE) reported contradictory or non-conclusive results. We performed a meta-analysis of five studies that examined the relationship between PE and the MMP9-1562C>T polymorphism. The PubMed, Embase, and Google Scholar databases were searched to access the relevant genetic association studies up to September 2013. The meta-analysis revealed that there was no evidence for significant association between MMP9-1562C>T polymorphism and risk of PE. Large, multiethnic confirmatory, and well-designed studies are needed to further explore the relation between preeclampsia and polymorphisms of the MMPs gene.     

Effect of exercise during pregnancy to prevent gestational diabetes mellitus: a systematic review and meta-analysis

Introduction: Exercise showed some potential in preventing gestational diabetes mellitus. However, the results remained controversial. We conducted a systematic review and meta-analysis to evaluate the impact of exercise during pregnancy on gestational diabetes mellitus.

Methods: PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases were systematically searched. Randomized controlled trials (RCTs) assessing the influence of exercise during pregnancy on gestational diabetes mellitus were included. Two investigators independently searched articles, extracted data, and assessed the quality of included studies. The primary outcome was the incidence of gestational diabetes mellitus. Meta-analysis was performed using random-effect model.

Results: Six RCTs involving 2164 patients were included in the meta-analysis. Compared with control intervention, exercise intervention was associated with significantly decreased incidence of gestational diabetes mellitus (Std. mean difference?=?0.59; 95%CI?=?0.39–.88; p?=?.01), but had no effect on gestational age at birth (Std. mean difference?=??0.03; 95%CI?=??0.12 to 0.07; p?=?.60), the number of preterm birth (OR?=?0.85; 95%CI?=?0.43–1.66; p?=?.63), glucose 2-h post-OGTT (Std. mean difference?=??1.02; 95%CI?=??2.75 to 0.71; p?=?.25), birth weight (Std. mean difference?=??0.13; 95%CI?=??0.26 to 0.01; p?=?.06), and Apgar score less than 7 (OR?=?.78; 95%CI?=?0.21–2.91; p?=?.71).

Conclusions: Compared to control intervention, exercise intervention could significantly decrease the risk of gestational diabetes mellitus, but showed no impact on gestational age at birth, preterm birth, glucose 2-h post-OGTT, birth weight, and Apgar score less than 7.     

Global and regional estimates of preeclampsia and eclampsia: a systematic review

Reduction of maternal mortality is a target within the Millennium Development Goals. Data on the incidence of preeclampsia and eclampsia, one of the main causes of maternal deaths, are required at both national and regional levels to inform policies. We conducted a systematic review of the incidence of hypertensive disorders of pregnancy (HDP) with the objective of evaluating its magnitude globally and in different regions and settings. We selected studies using pre-specified criteria, recorded database characteristics and assessed methodological quality of the eligible studies reporting incidence of any HDP during the period 2002–2010. A logistic model was then developed to estimate the global and regional incidence of HDP using pre-specified predictor variables where empiric data were not available. We found 129 studies meeting the inclusion criteria, from which 74 reports with 78 datasets reporting HDP were analysed. This represents nearly 39 million women from 40 countries. When the model was applied, the overall estimates are 4.6% (95% uncertainty range 2.7–8.2), and 1.4% (95% uncertainty range 1.0–2.0) of all deliveries for preeclampsia and eclampsia respectively, with a wide variation across regions. The figures we obtained give a general idea of the magnitude of the problem and suggest that some regional variations might exist. The absence of data in many countries is of concern, however, and efforts should be made to implement data collection and reporting for substantial statistics. The implementation of large scale surveys conducted during a short period of time could provide more reliable and up-to-date estimations to inform policy.     

The association between Mullerian anomalies and IUGR: a meta-analysis

Background: Published literature regarding the association between Mullerian anomalies and intrauterine growth restriction (IUGR) is controversial. To date, no meta-analysis has been performed for assessing the relationship between the Mullerian anomalies and IUGR. Therefore, the aim of this study was to perform a meta-analysis by combining data from relevant studies to assessing the association of between Mullerian anomalies and IUGR.

Methods: A systematic search was conducted in PubMed, Scopus and Web of Science to identify of all studies prior to September 2017. Egger’s and Begg’s tests were carried out to quantitatively assess publication bias. To estimate the heterogeneity among studies the Q-statistic test and I-squared (I²) test were used. The random-effects model was conducted to obtain pooled odds ratio (OR) as a measure of the association between Mullerian anomalies and IUGR.

Results: A total of seven studies were included in this meta-analysis with a sample of 605,005 participants. The pooled overall OR was 1.93 (95% CI: 1.52, 2.34).

Conclusions: We reported that mullerian anomalies are a risk factor for IUGR. However, further evidence by larger prospective cohort studies is needed to make conclusive evidence regarding the association between mullerian anomalies and IUGR.     

One step versus two step approach for gestational diabetes screening: systematic review and meta-analysis of the randomized trials

Introduction: To compare both the prevalence of gestational diabetes mellitus (GDM) as well as maternal and neonatal outcomes by either the one-step or the two-step approaches.

Material and methods: Electronic databases were searched from their inception until June 2017. We included all randomized controlled trials (RCTs) comparing the one-step with the two-step approaches for the screening and diagnosis of GDM. The primary outcome was the incidence of GDM.

Results: Three RCTs (n?=?2333 participants) were included in the meta-analysis. 910 were randomized to the one step approach (75?g, 2?hrs), and 1423 to the two step approach. No significant difference in the incidence of GDM was found comparing the one step versus the two step approaches (8.4 versus 4.3%; relative risk (RR) 1.64, 95%CI 0.77–3.48). Women screened with the one step approach had a significantly lower risk of preterm birth (PTB) (3.7 versus 7.6%; RR 0.49, 95%CI 0.27–0.88), cesarean delivery (16.3 versus 22.0%; RR 0.74, 95%CI 0.56–0.99), macrosomia (2.9 versus 6.9%; RR 0.43, 95%CI 0.22–0.82), neonatal hypoglycemia (1.7 versus 4.5%; RR 0.38, 95%CI 0.16–0.90), and admission to neonatal intensive care unit (NICU) (4.4 versus 9.0%; RR 0.49, 95%CI 0.29–0.84), compared to those randomized to screening with the two step approach.

Conclusions: The one and the two step approaches were not associated with a significant difference in the incidence of GDM. However, the one step approach was associated with better maternal and perinatal outcomes.     

Maternal serum and fetal cord-blood ischemia-modified albumin concentrations in normal pregnancy and preeclampsia: a systematic review and meta-analysis

Background/aims: A meta-analysis of maternal serum ischemia-modified albumin (IMA) and fetal cord-blood IMA concentrations in normal pregnancy (NP) compared to non-pregnant healthy controls (HC) and in preeclampsia (PE) compared with normal pregnant controls were studied.

Methods: All major databases were searched for eligible studies. We included eight studies comparing serum IMA between NP and HC, 14 studies comparing serum IMA between PE and NP and five studies comparing cord-blood IMA between PE and NP groups. Meta-analyses on these included studies were performed using Review Manager 5.3. Pooled-overall effect size as standardized mean difference (SMD), publication bias, subgroup, and sensitivity analysis data were generated.

Results: Random-effects meta-analysis indicated a significant increase in serum IMA in the NP group (SMD?=?0.98, p?=?.01) and the PE group (SMD?=?0.94, p?p?Conclusions: This meta-analysis, the first of its kind showed that the increased serum IMA concentrations were indicative of increased oxidative stress in NP and PE. Measurement of maternal serum IMA and fetal cord-blood IMA concentrations were useful as simple, novel, and inexpensive markers of oxidative stress (OS) status in PE patients. Future large-scale studies are needed to explore IMA in relationship to the disease severity in PE.     

The association between body mass index and preeclampsia: a meta-analysis

Background: Several observational studies have reported a positive association between elevated body mass index (BMI) and preeclampsia, but no meta-analysis has been conducted yet. This meta-analysis was conducted to estimate the overall association between overweight or obesity and preeclampsia.

Methods: Major electronic databases, including PubMed, Web of Science, and Scopus were searched until August 2015. The reference lists of included studies were screened as well. Epidemiological studies addressing the association between BMI and preeclampsia were enrolled. The heterogeneity across studies was explored by Q-test and I² statistic. The possibility of publication bias was assessed using Begg's and Egger's tests. The results were reported using odds ratio (OR) estimate with its 95% confidence intervals (CI) using a random-effects model.

Results: We identified a total of 1298 references and included 23 studies with 1 387 599 participants. Preeclampsia was associated with overweight (OR?=?1.73; 95% CI: 1.59, 1.87; 21 studies; I^2?=^?62.3%) and obesity (OR?=?3.15; 95% CI: 2.96, 3.35; 22 studies; I^2?=^?36.0%). There was no evidence of publication bias.

Conclusions: There is sufficient evidence that excess body mass index is significantly associated with an increased risk of preeclampsia. Therefore, overweight and obesity can be considered as a predictor of preeclampsia.