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Pregnancy Hypertension Dec 2023Human chorionic gonadotropin (hCG), a glycoprotein produced in the placenta, is crucial for a healthy pregnancy. We investigated the relationship between hCG levels and... (Meta-Analysis)
Meta-Analysis Review
Human chorionic gonadotropin (hCG), a glycoprotein produced in the placenta, is crucial for a healthy pregnancy. We investigated the relationship between hCG levels and adverse pregnancy outcomes. We conducted a systematic review including studies measuring hCG blood levels in the first or second trimester, reporting on any of the 12 predefined adverse pregnancy outcomes with logistic regression-adjusted association estimates. The primary outcomes were placenta-associated complications, such as miscarriage, preeclampsia, intrauterine growth restriction, and preterm delivery. We searched PubMed, Embase and CINAHL Complete. The hCG levels were analysed as multiple of the median (MoM). Odds ratio (OR) and 95% confidence interval (CI) were used. Risk of bias and the certainty of evidence were assessed using ROBINS-I and GRADE, respectively. Meta-analysis also showed that hCG levels, reported as MoM ≥2/2.31/2.5, might be associated with an increased risk of preeclampsia (OR 2.08, 95% CI 1.26 to 3.44) and preterm delivery (OR 1.29, 95% CI 1.12 to 1.47), but the evidence is very uncertain. High second trimester hCG levels may be associated with preeclampsia and preterm delivery but confidence in evidence is low.
Topics: Pregnancy; Infant, Newborn; Female; Humans; Premature Birth; Pre-Eclampsia; Pregnancy Outcome; Chorionic Gonadotropin; Abortion, Spontaneous; Pregnancy Trimester, Second
PubMed: 37951184
DOI: 10.1016/j.preghy.2023.11.003 -
International Journal of Public Health 2023Preterm birth (PTB) is considered as a public health problem and one of the main risk factors related to the global disease burden. The purpose of this study aims to... (Meta-Analysis)
Meta-Analysis Review
Preterm birth (PTB) is considered as a public health problem and one of the main risk factors related to the global disease burden. The purpose of this study aims to explore the influence of exposure to major air pollutants at different pregnancies on PTB. The relationship between air pollutants and PTB in China was collected from cohort studies and case-control studies published before 30 April 2022. Meta-analysis was carried out with STATA 15.0 software. A total of 2,115 papers were retrieved, of which 18 papers met the inclusion criteria. The comprehensive effect of pollutant exposure and PTB were calculated. PM during entire pregnancy and O exposure during third trimester were positively associated with preterm birth. Every 10 μg/m increase in the average concentration of PM during the whole pregnancy will increase the risk of premature delivery by 4%, and every 10 μg/m increase in the average concentration of O in the third trimester will increase the risk of premature delivery by 1%. Exposure to PM entire prenatal pregnancy and O in third trimester is associated with an increased risk of preterm birth occurrence.
Topics: Pregnancy; Female; Infant, Newborn; Humans; Air Pollutants; Premature Birth; Air Pollution; China; Particulate Matter; Maternal Exposure
PubMed: 37876739
DOI: 10.3389/ijph.2023.1606226 -
Maternal Anemia during pregnancy and infant low birth weight: A systematic review and Meta-analysis.International Journal of Reproductive... Mar 2017Infant low birth weight is one of the major problems in different societies. Different reports have provided different results regarding the relationship between... (Review)
Review
BACKGROUND
Infant low birth weight is one of the major problems in different societies. Different reports have provided different results regarding the relationship between maternal anemia and infant low birth weight in different months of pregnancy.
OBJECTIVE
The aim of this study was to determine the relationship between maternal anemia during pregnancy and infant low birth weight.
MATERIALS AND METHODS
This systematic review was conducted using related keywords in national (Sid, Iran.doc, Iran medex and Magiran) and international (PubMed, Science Direct, Cochrane, Medline, Web of Science, Scopus, Springer, Embase, Google scholar) databases. Relative risks and confidence intervals were extracted from each study. The results were combined using random-effects model for meta-analysis. The I index was also used to measure heterogeneity between the studies.
RESULTS
Overall, 17 studies with a total sample size of 245407 entered the final meta-analysis and demonstrated that the relative risk for maternal anemia in the first, second and third trimester of pregnancy were 1.26 (95% CI: 1.03-1.55), 0.97 (95% CI: 0.57-1.65), and 1.21 (95% CI: 0.84-1.76), respectively. The relationship between maternal anemia and infant low birth weight in the first trimester of pregnancy was significant.
CONCLUSION
Maternal anemia, especially during the first trimester of pregnancy, can be considered as a risk factor for pregnancy outcomes. Therefore, one needs to take the necessary steps to cure this disease in order to reduce the incidence of infant low birth weight.
PubMed: 28580444
DOI: No ID Found -
Nutrition Journal Oct 2016The association between serum selenium level and gestational diabetes mellitus (GDM) is controversial. The aim of our study was to systematically review available... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
The association between serum selenium level and gestational diabetes mellitus (GDM) is controversial. The aim of our study was to systematically review available literature linking selenium to GDM for a comprehensive understanding of the relationship between serum selenium level and GDM in human.
METHODS
PubMed, The Cochrane Library and Medline were searched for studies published up to August 2016. Manual searches of references of the relevant original studies were carried out. Pooled estimates were measured using the fixed or random effect model. Overall effect was reported in a standard mean difference (SMD). All data were analyzed with Review Manager 5.3 and Stata 12.0.
RESULTS
Of 44 references reviewed, seven studies involving 569 patients met our inclusion criteria and contributed to meta-analysis. All the studies were used to evaluate the relationship between serum selenium level and GDM. Selenium level was significantly lower in women with GDM than those without GDM (SMD = -1.17; 95 % CI: -1.98 to -0.35, P = 0.005). Subgroup analysis showed that such trend was consistent within the non-Caucasian population (Asia: SMD = -2.82; 95 % CI: -5.21 to -0.43, P = 0.02; Africa: SMD = -0.56; 95 % CI: -1.07 to -0.05, P = 0.03) and in the third trimester (SMD = -1.78; 95 % CI: -3.04 to -0.52, P = 0.006), but not within the Caucasian population (Europe: SMD = -0.6; 95 % CI: -1.98 to 0.78, P = 0.39) or in the second trimester (SMD = -0.68; 95 % CI: -1.6 to 0.25, P = 0.15).
CONCLUSIONS
The available evidences suggested that serum selenium level was lower in women with GDM than those with normal glucose tolerance, especially within the non-Caucasian population and in the third trimester. However, well-designed prospective studies are needed to understand dynamic associations between selenium status and GDM risk.
Topics: Adult; Diabetes, Gestational; Female; Humans; Pregnancy; Pregnancy Trimester, Third; Racial Groups; Selenium
PubMed: 27793207
DOI: 10.1186/s12937-016-0211-8 -
A systematic review and meta-analysis of prevalence of insomnia in the third trimester of pregnancy.BMC Pregnancy and Childbirth Apr 2021Sleep disorders, which are among the foremost important medical care issues, are prevalent in pregnancy. The present study is a meta-analysis of the prevalence of... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Sleep disorders, which are among the foremost important medical care issues, are prevalent in pregnancy. The present study is a meta-analysis of the prevalence of insomnia in the third trimester of pregnancy. This study aims to systematically review the overall prevalence of insomnia in the third trimester of pregnancy through conducting a meta-analysis.
METHOD
The literature used in this meta-analysis for the topic discussed above were obtained through searching several databases, including SID, MagIran, IranDoc, Scopus, Embase, Web of Science (WoS), PubMed Science Direct and Google Scholar databases without time limitation until December 2020. Articles developed based on cross-sectional studies were included in the study. The heterogeneity of studies was investigated using the I index. Also, the possible effects of heterogeneity in the studied studies are investigated using meta-regression analysis.
RESULT
In 10 articles and 8798 participants aged between11-40, the overall prevalence of insomnia in the third trimester of pregnancy based on meta-analysis was 42.4% (95% CI: 32.9-52.5%). It was reported that as the sample size increases, the prevalence of insomnia in the third trimester of pregnancy increases. Conversely, as the year of research increases, the prevalence of insomnia in the third trimester of pregnancy decreases. Both of these differences were statistically significant (P < 0.05).
CONCLUSION
Insomnia was highly prevalent in the last trimester of pregnancy. Sleep disorders are neglected among pregnant women, and they are considered natural. While sleep disturbances can cause mental and physical problems in pregnant women, they can consequently cause problems for the fetus. As a result, maintaining the physical and mental health of pregnant mothers is very important. It is thus recommended that in addition to having regular visits during pregnancy, pregnant women should also be continuously monitored for sleep-related disorders.
Topics: Female; Humans; Pregnancy; Pregnancy Complications; Pregnancy Trimester, Third; Prevalence; Sleep Initiation and Maintenance Disorders
PubMed: 33836686
DOI: 10.1186/s12884-021-03755-z -
BMJ (Clinical Research Ed.) Oct 2014To determine the impact of cervical excision for cervical intraepithelial neoplasia on fertility and early pregnancy outcomes. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
To determine the impact of cervical excision for cervical intraepithelial neoplasia on fertility and early pregnancy outcomes.
DESIGN
Systematic review and meta-analysis of cohort studies.
DATA SOURCES
Medline and Embase.
ELIGIBILITY CRITERIA
Studies assessing fertility and early pregnancy outcomes in women with a history of treatment for cervical intraepithelial neoplasia versus untreated women. We classified the included studies according to treatment type and fertility or early pregnancy endpoint.
ANALYSIS
Pooled relative risks and 95% confidence intervals using a random effect model, and interstudy heterogeneity with I(2) statistics.
RESULTS
15 studies fulfilled the inclusion criteria and were included. The meta-analysis did not provide any evidence that treatment for cervical intraepithelial neoplasia adversely affected the chances of conception. The overall pregnancy rate was higher for treated women than for untreated women (four studies; 43% v 38%, pooled relative risk 1.29, 95% confidence interval 1.02 to 1.64), although the heterogeneity between studies was high (P<0.0001). Pregnancy rates did not differ between women with an intention to conceive (two studies; 88% v 95%, 0.93, 0.80 to 1.08) and the number requiring more than 12 months to conceive (three studies, 15% v 9%, 1.45, 0.89 to 2.37). Although the rates for total miscarriages (10 studies; 4.6% v 2.8%, 1.04, 0.90 to 1.21) and miscarriage in the first trimester (four studies; 9.8% v 8.4%, 1.16, 0.80 to 1.69) was similar for treated and untreated women, cervical treatment was associated with a significantly increased risk of miscarriage in the second trimester. The rate was higher for treated women than for untreated women (eight studies; 1.6% v 0.4%, 16,558 women; 2.60, 1.45 to 4.67). The number of ectopic pregnancies (1.6% v 0.8%; 1.89, 1.50 to 2.39) and terminations (12.2% v 7.4%; 1.71, 1.31 to 2.22) was also higher for treated women.
CONCLUSION
There is no evidence suggesting that treatment for cervical intraepithelial neoplasia adversely affects fertility, although treatment was associated with a significantly increased risk of miscarriages in the second trimester. Research should explore mechanisms that may explain this increase in risk and stratify the impact that treatment may have on fertility and early pregnancy outcomes by the size of excision and treatment method used.
Topics: Cervix Uteri; Conization; Female; Fertility; Humans; Models, Statistical; Postoperative Complications; Pregnancy; Pregnancy Complications; Pregnancy Outcome; Pregnancy Rate; Uterine Cervical Neoplasms; Uterine Cervical Dysplasia
PubMed: 25352501
DOI: 10.1136/bmj.g6192 -
BJOG : An International Journal of... Apr 2015Lipid levels during pregnancy in women with gestational diabetes mellitus (GDM) have been extensively studied; however, it remains unclear whether dyslipidaemia is a... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Lipid levels during pregnancy in women with gestational diabetes mellitus (GDM) have been extensively studied; however, it remains unclear whether dyslipidaemia is a potential marker of preexisting insulin resistance.
OBJECTIVE
To evaluate the relationship between lipid measures throughout pregnancy and GDM.
SEARCH STRATEGY
We searched PubMed-MedLine and SCOPUS (inception until January 2014) and reference lists of relevant studies.
SELECTION CRITERIA
Publications describing original data with at least one raw lipid (total cholesterol, high-density lipoprotein cholesterol [HDL-C], low-density lipoprotein cholesterol [LDL-C], or triglyceride) measurement during pregnancy in women with GDM and healthy pregnant controls were retained.
DATA COLLECTION AND ANALYSIS
Data extracted from 60 studies were pooled and weighted mean difference (WMD) in lipid levels was calculated using random effects models. Meta-regression was also performed to identify sources of heterogeneity.
MAIN RESULTS
Triglyceride levels were significantly elevated in women with GDM compared with those without GDM (WMD 30.9, 95% confidence interval [95% CI] 25.4-36.4). This finding was consistent in the first, second and third trimesters of pregnancy. HDL-C levels were significantly lower in women with GDM compared with those without GDM in the second (WMD -4.6, 95% CI -6.2 to -3.1) and third (WMD -4.1, 95% CI -6.5 to -1.7) trimesters of pregnancy. There were no differences in aggregate total cholesterol or LDL-C levels between women with GDM and those without insulin resistance.
AUTHOR'S CONCLUSIONS
Our meta-analysis shows that triglycerides are significantly elevated among women with GDM compared with women without insulin resistance and this finding persists across all three trimesters of pregnancy.
Topics: Diabetes, Gestational; Dyslipidemias; Female; Humans; Insulin Resistance; Lipids; Mothers; Observational Studies as Topic; Pregnancy; Pregnancy Trimesters; Risk Factors; Triglycerides
PubMed: 25612005
DOI: 10.1111/1471-0528.13261 -
Gynecological Endocrinology : the... Jun 2023Serum uric acid (SUA) is considered as a risk factor for gestational diabetes mellitus (GDM). However, current studies showed inconsistent results. This study aimed to... (Meta-Analysis)
Meta-Analysis Review
AIMS
Serum uric acid (SUA) is considered as a risk factor for gestational diabetes mellitus (GDM). However, current studies showed inconsistent results. This study aimed to explore the relationship between SUA levels and GDM risk.
METHODS
Eligible studies were retrieved from PubMed, Web of Science, Embase, China National Knowledge Infrastructure, and Wanfang databases up to November 1, 2022. The pooled standardized mean difference (SMD) and 95% confidence interval (CI) were used to represent the difference in SUA levels between GDM women and controls. The combined odds ratios (OR) and 95% CI were applied to assess association between SUA levels and GDM risk. Subgroup analyses were conducted on study continents, design, and quality, detection time of SUA, and GDM diagnostic criteria.
RESULTS
Totally 11 studies including five case-control and six cohort studies, in which 80,387 pregnant women with 9815 GDM were included. The overall meta-analysis showed that the mean SUA level in GDM group was significantly higher than in controls (SMD = 0.423, 95%CI = 0.019-0.826, = .040, = 93%). Notably, pregnant women with elevated levels of SUA had a significantly increased risk of GDM (OR = 1.670, 95%CI = 1.184-2.356, = .0035, = 95%). Furthermore, subgroup analysis performed on the detection time of SUA showed a significant difference in the association between SUA and GDM risk within different trimesters (1st trimester: OR = 3.978, 95%CI = 2.177-7.268; 1st to 2nd trimester: OR = 1.340, 95%CI = 1.078-1.667; between subgroups <.01).
CONCLUSIONS
Elevated SUA was positively associated with GDM risk, particularly in the 1st trimester of pregnancy. Further studies with high quality are required to validate the findings of this study.
Topics: Pregnancy; Female; Humans; Diabetes, Gestational; Uric Acid; Pregnancy Trimester, First; Risk Factors; Pregnancy Trimester, Second
PubMed: 37406646
DOI: 10.1080/09513590.2023.2231101 -
American Journal of Obstetrics &... Jul 2023Many studies have reported the association between platelets and preeclampsia. However, sample sizes were small, and their findings were inconsistent. We conducted a... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
Many studies have reported the association between platelets and preeclampsia. However, sample sizes were small, and their findings were inconsistent. We conducted a systematic review and meta-analysis to evaluate the association in pooled samples and in detail.
DATA SOURCES
A systematic literature search was performed using Medline, Embase, ScienceDirect, Web of Science, Cochrane Library, NICHD-DASH, LILACS, and Scopus from inception to April 22, 2022.
STUDY ELIGIBILITY CRITERIA
Observational studies comparing platelet count between women with preeclampsia and normotensive pregnant women were included.
METHODS
The mean differences with 95% confidence interval in platelet count were calculated. Heterogeneity was assessed using I statistics. Sensitivity and subgroup analyses were conducted. Statistical analysis was performed using RevMan 5.3 and ProMeta 3 software.
RESULTS
A total of 56 studies comprising 4892 preeclamptic and 9947 normotensive pregnant women were included. Meta-analysis showed that platelet count was significantly lower in women with preeclampsia than in normotensive controls (overall: mean difference, -32.83; 95% confidence interval, -40.13 to -25.52; P<.00001; I=92%; mild preeclampsia: mean difference, -18.65; 95% confidence interval, -27.17 to -10.14; P<.00001; I=84%; severe preeclampsia: mean difference, -42.61; 95% confidence interval, -57.53 to -27.68; P<.00001; I=94%). Significantly lower platelet count was also observed in the second trimester (mean difference, -28.84; 95% confidence interval, -44.59 to -13.08; P=.0003; I=93%), third trimester (mean difference, -40.67; 95% confidence interval, -52.14 to -29.20; P<.00001; I=92%), and before the diagnosis of preeclampsia (mean difference, -18.81; 95% confidence interval, -29.98 to -7.64; P=.009; I=87%), but not in the first trimester (mean difference, -15.14; 95% confidence interval, -37.71 to 7.43; P=.19; I=71%). Overall, the pooled sensitivity and specificity of platelet count were 0.71 and 0.77, respectively. The area under the curve was 0.80.
CONCLUSION
This meta-analysis confirmed that platelet count was significantly lower in preeclamptic women, irrespective of severity and presence or absence of associated complications, even before the onset of preeclampsia and in the second trimester of pregnancy. Our findings suggest that platelet count may be a potential marker to identify and predict preeclampsia.
Topics: Pregnancy; Female; Humans; Pre-Eclampsia; Platelet Count; Blood Pressure; Pregnancy Trimester, First; Pregnancy Trimester, Third
PubMed: 37098392
DOI: 10.1016/j.ajogmf.2023.100979 -
Human Reproduction Update 2014Metformin is generally considered a non-teratogenic drug; however, only a few studies specifically designed to assess the rate of congenital anomalies after metformin... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Metformin is generally considered a non-teratogenic drug; however, only a few studies specifically designed to assess the rate of congenital anomalies after metformin use have been published in the literature. The objects of the present study were to review all of the prospective and retrospective studies reporting on women treated with metformin at least during the first trimester of their pregnancy and to estimate the overall rate of major birth defects.
METHODS
Databases were searched for English language articles until December 2013. Inclusion criteria for the meta-analysis were: a case group of women with PCOS or pre-pregnancy type 2 diabetes and first-trimester exposure to metformin; a disease-matched control group which was not exposed to metformin or other oral anti-diabetic agents; and a list of the major anomalies in both the study and the control groups. A random effects model was used for the meta-analysis of data, using odds ratios. Studies not fulfilling the inclusion criteria for the meta-analysis but reporting relevant data on major malformations in women diagnosed with PCOS were then used to estimate the overall birth defects rate.
RESULTS
Meta-analysis of nine controlled studies with women affected by PCOS detected that the rate of major birth defects in the metformin-exposed group was not statistically increased compared with the disease-matched control group and that there was no significant heterogeneity among the studies. The metformin-exposed sample was composed of 351 pregnancies and the OR of major birth defects was 0.86 (95% confidence interval: 0.18-4.08; Pheterogeneity = 0.71). By evaluating all of the non-overlapping PCOS studies reported in the literature, even those without an appropriate control group, the overall rate of major anomalies was 0.6% in the sample of 517 women who discontinued the therapy upon conception or confirmation of pregnancy and 0.5% in the sample of 634 women who were treated with metformin throughout the first trimester of their pregnancy. Regarding type 2 diabetic women, we did not identify a sufficient number of studies with metformin exposure during the first trimester to proceed with the meta-analysis.
CONCLUSIONS
There is currently no evidence that metformin is associated with an increased risk of major birth defects in women affected by PCOS and treated during the first trimester. However larger ad hoc studies are warranted in order to definitely confirm the safety and efficacy of this drug in pregnancy.
Topics: Abnormalities, Drug-Induced; Female; Humans; Hypoglycemic Agents; Infant, Newborn; Maternal-Fetal Exchange; Metformin; Polycystic Ovary Syndrome; Pregnancy; Pregnancy Complications; Pregnancy Trimester, First; Pregnancy in Diabetics; Prenatal Exposure Delayed Effects; Prospective Studies; Retrospective Studies
PubMed: 24861556
DOI: 10.1093/humupd/dmu022