scholarly journals Spiral artery blood flow during pregnancy: a systematic review and meta-analysis.

2019 ◽  
Author(s):  
Veronique Schiffer ◽  
Laura Evers ◽  
Sander de Haas ◽  
Chahinda Ghossein ◽  
Salwan Al-Nasiry ◽  
...  
Keyword(s):  
Systematic Review ◽  
Blood Flow ◽  
Meta Analysis ◽  
Resistance Index ◽  
First Trimester ◽  
Trophoblast Invasion ◽  
Cochrane Library ◽  
Second Trimester ◽  
Spiral Artery ◽  
Third Trimester

Abstract Background: Downstream remodeling of the spiral arteries (SpA) decreases utero-placental resistance drastically, allowing sustained and increased blood flow to the placenta at all circumstances. We systematically evaluated available reports to visualize adaptation of spiral arteries throughout pregnancy by ultra-sonographic measurements and evaluated when this process is completed.Methods: A systematic review and meta-analysis of spiral artery flow (pulsatility index (PI), resistance index (RI) and peak systolic velocity (PSV)) was performed. English articles were obtained from Pubmed, EMBASE and Cochrane Library and included articles were assessed on quality and risk of bias. Weighted means of Doppler indices were calculated using a random-effects model. Results: In healthy pregnancies, PI and RI decreased from 0.75 (95% CI: 0.67-0.83) and 0.49 (95% CI: 0.46-0.53) in the first trimester to 0.52 (95% CI: 0.48-0.56, p=0.003) and 0.40 (95% CI: 0.38-0.42, p=0.080) in the second trimester and to 0.49 (95% CI: 0.44-0.53, p=0.510) and 0.36 (95% CI: 0.35-0.37, p=0.307) in the third trimester, respectively. In parallel, PSV altered from 0.24 m/s (95% CI: 0.17-0.31 m/s) to 0.28 m/s (95% CI: 0.22-0.34 m/s, p=0.377) and to 0.25 m/s (95% CI: 0.21-0.28 m/s, p=0.919) in the three trimesters. In absence of second and third trimester Doppler data in complicated gestation, only a difference in PI was observed between complicated and healthy pregnancies during the first trimester (1.49 vs 0.76, p<0.001). Although individual studies have identified differences in PI between SpA located in the central part of the placental bed versus those located at its periphery, this meta-analysis could not confirm this (p=0.349).Conclusions: This review and meta-analysis concludes that an observed decrease of SpA PI and RI from the first towards the second trimester parallels the physiological trophoblast invasion converting SpA during early gestation, a process completed in the midst of the second trimester. Higher PI and RI were found in SpA of complicated pregnancies compared to healthy pregnancies, possibly reflecting suboptimal utero-placental circulation. Longitudinal studies examining comprehensively the predictive value of spiral artery Doppler for complicated pregnancies are yet to be carried out.

scholarly journals Spiral artery blood flow during pregnancy: a systematic review and meta-analysis.

2020 ◽  
Author(s):  
Veronique Schiffer ◽  
Laura Evers ◽  
Sander de Haas ◽  
Chahinda Ghossein ◽  
Salwan Al-Nasiry ◽  
...  
Keyword(s):  
Systematic Review ◽  
Blood Flow ◽  
Meta Analysis ◽  
Resistance Index ◽  
First Trimester ◽  
Trophoblast Invasion ◽  
Cochrane Library ◽  
Second Trimester ◽  
Spiral Artery ◽  
Third Trimester

Abstract Background: Downstream remodeling of the spiral arteries (SpA) decreases utero-placental resistance drastically, allowing sustained and increased blood flow to the placenta at all circumstances. We systematically evaluated available reports to visualize adaptation of spiral arteries throughout pregnancy by ultra-sonographic measurements and evaluated when this process is completed. Methods: A systematic review and meta-analysis of spiral artery flow (pulsatility index (PI), resistance index (RI) and peak systolic velocity (PSV)) was performed. English articles were obtained from Pubmed, EMBASE and Cochrane Library and included articles were assessed on quality and risk of bias. Weighted means of Doppler indices were calculated using a random-effects model. Results: In healthy pregnancies, PI and RI decreased from 0.80 (95% CI: 0.70-0.89) and 0.50 (95% CI: 0.47-0.54) in the first trimester to 0.50 (95% CI: 0.45-0.55, p<0.001) and 0.39 (95% CI: 0.37-0.42, p<0.001) in the second trimester and to 0.49 (95% CI: 0.44-0.53, p=0.752) and 0.36 (95% CI: 0.35-0.38, p=0.037) in the third trimester, respectively. In parallel, PSV altered from 0.22 m/s (95% CI: 0.13-0.30 m/s) to 0.28 m/s (95% CI: 0.17-0.40 m/s, p=0.377) and to 0.25 m/s (95% CI: 0.20-0.30 m/s, p=0.560) in the three trimesters. In absence of second and third trimester Doppler data in complicated gestation, only a difference in PI was observed between complicated and healthy pregnancies during the first trimester (1.49 vs 0.80, p<0.001). Although individual studies have identified differences in PI between SpA located in the central part of the placental bed versus those located at its periphery, this meta-analysis could not confirm this (p=0.349). Conclusions: This review and meta-analysis concludes that an observed decrease of SpA PI and RI from the first towards the second trimester parallels the physiological trophoblast invasion converting SpA during early gestation, a process completed in the midst of the second trimester. Higher PI was found in SpA of complicated pregnancies compared to healthy pregnancies, possibly reflecting suboptimal utero-placental circulation. Longitudinal studies examining comprehensively the predictive value of spiral artery Doppler for complicated pregnancies are yet to be carried out.

scholarly journals Spiral artery blood flow during pregnancy: a systematic review and meta-analysis.

2020 ◽  
Author(s):  
Veronique Schiffer ◽  
Laura Evers ◽  
Sander de Haas ◽  
Chahinda Ghossein ◽  
Salwan Al-Nasiry ◽  
...  
Keyword(s):  
Systematic Review ◽  
Blood Flow ◽  
Meta Analysis ◽  
Resistance Index ◽  
First Trimester ◽  
Trophoblast Invasion ◽  
Cochrane Library ◽  
Second Trimester ◽  
Spiral Artery ◽  
Third Trimester

Abstract Background: Downstream remodeling of the spiral arteries (SpA) decreases utero-placental resistance drastically, allowing sustained and increased blood flow to the placenta at all circumstances. We systematically evaluated available reports to visualize adaptation of spiral arteries throughout pregnancy by ultra-sonographic measurements and evaluated when this process is completed. Methods: A systematic review and meta-analysis of spiral artery flow (pulsatility index (PI), resistance index (RI) and peak systolic velocity (PSV)) was performed. English articles were obtained from Pubmed, EMBASE and Cochrane Library and included articles were assessed on quality and risk of bias. Weighted means of Doppler indices were calculated using a random-effects model. Results: In healthy pregnancies, PI and RI decreased from 0.80 (95% CI: 0.70-0.89) and 0.50 (95% CI: 0.47-0.54) in the first trimester to 0.50 (95% CI: 0.45-0.55, p<0.001) and 0.39 (95% CI: 0.37-0.42, p<0.001) in the second trimester and to 0.49 (95% CI: 0.44-0.53, p=0.752) and 0.36 (95% CI: 0.35-0.38, p=0.037) in the third trimester, respectively. In parallel, PSV altered from 0.22 m/s (95% CI: 0.13-0.30 m/s) to 0.28 m/s (95% CI: 0.17-0.40 m/s, p=0.377) and to 0.25 m/s (95% CI: 0.20-0.30 m/s, p=0.560) in the three trimesters. In absence of second and third trimester Doppler data in complicated gestation, only a difference in PI was observed between complicated and healthy pregnancies during the first trimester (1.49 vs 0.80, p<0.001). Although individual studies have identified differences in PI between SpA located in the central part of the placental bed versus those located at its periphery, this meta-analysis could not confirm this (p=0.349). Conclusions: This review and meta-analysis concludes that an observed decrease of SpA PI and RI from the first towards the second trimester parallels the physiological trophoblast invasion converting SpA during early gestation, a process completed in the midst of the second trimester. Higher PI was found in SpA of complicated pregnancies compared to healthy pregnancies, possibly reflecting suboptimal utero-placental circulation. Longitudinal studies examining comprehensively the predictive value of spiral artery Doppler for complicated pregnancies are yet to be carried out.

scholarly journals Spiral artery blood flow during pregnancy: a systematic review and meta-analysis.

2020 ◽  
Author(s):  
Veronique Schiffer ◽  
Laura Evers ◽  
Sander de Haas ◽  
Chahinda Ghossein ◽  
Salwan Al-Nasiry ◽  
...  
Keyword(s):  
Systematic Review ◽  
Blood Flow ◽  
Meta Analysis ◽  
Resistance Index ◽  
First Trimester ◽  
Trophoblast Invasion ◽  
Cochrane Library ◽  
Second Trimester ◽  
Spiral Artery ◽  
Third Trimester

Abstract Background: Downstream remodeling of the spiral arteries (SpA) decreases utero-placental resistance drastically, allowing sustained and increased blood flow to the placenta at all circumstances. We systematically evaluated available reports to visualize adaptation of spiral arteries throughout pregnancy by ultra-sonographic measurements and evaluated when this process is completed.Methods: A systematic review and meta-analysis of spiral artery flow (pulsatility index (PI), resistance index (RI) and peak systolic velocity (PSV)) was performed. English articles were obtained from Pubmed, EMBASE and Cochrane Library and included articles were assessed on quality and risk of bias. Weighted means of Doppler indices were calculated using a random-effects model. Results: In healthy pregnancies, PI and RI decreased from 0.80 (95% CI: 0.70-0.89) and 0.50 (95% CI: 0.47-0.54) in the first trimester to 0.50 (95% CI: 0.45-0.55, p<0.001) and 0.39 (95% CI: 0.37-0.42, p<0.001) in the second trimester and to 0.49 (95% CI: 0.44-0.53, p=0.752) and 0.36 (95% CI: 0.35-0.38, p=0.037) in the third trimester, respectively. In parallel, PSV altered from 0.22 m/s (95% CI: 0.13-0.30 m/s) to 0.28 m/s (95% CI: 0.17-0.40 m/s, p=0.377) and to 0.25 m/s (95% CI: 0.20-0.30 m/s, p=0.560) in the three trimesters. In absence of second and third trimester Doppler data in complicated gestation, only a difference in PI was observed between complicated and healthy pregnancies during the first trimester (1.49 vs 0.80, p<0.001). Although individual studies have identified differences in PI between SpA located in the central part of the placental bed versus those located at its periphery, this meta-analysis could not confirm this (p=0.349).Conclusions: This review and meta-analysis concludes that an observed decrease of SpA PI and RI from the first towards the second trimester parallels the physiological trophoblast invasion converting SpA during early gestation, a process completed in the midst of the second trimester. Higher PI was found in SpA of complicated pregnancies compared to healthy pregnancies, possibly reflecting suboptimal utero-placental circulation. Longitudinal studies examining comprehensively the predictive value of spiral artery Doppler for complicated pregnancies are yet to be carried out.

scholarly journals Spiral artery blood flow during pregnancy: a systematic review and meta-analysis

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Veronique Schiffer ◽  
Laura Evers ◽  
Sander de Haas ◽  
Chahinda Ghossein-Doha ◽  
Salwan Al-Nasiry ◽  
...  
Keyword(s):  
Systematic Review ◽  
Blood Flow ◽  
Meta Analysis ◽  
Resistance Index ◽  
First Trimester ◽  
Trophoblast Invasion ◽  
Cochrane Library ◽  
Second Trimester ◽  
Spiral Artery ◽  
Third Trimester

Abstract Background Downstream remodeling of the spiral arteries (SpA) decreases utero-placental resistance drastically, allowing sustained and increased blood flow to the placenta under all circumstances. We systematically evaluated available reports to visualize adaptation of spiral arteries throughout pregnancy by ultra-sonographic measurements and evaluated when this process is completed. Methods A systematic review and meta-analysis of spiral artery flow (pulsatility index (PI), resistance index (RI) and peak systolic velocity (PSV)) was performed. English written articles were obtained from Pubmed, EMBASE and Cochrane Library and included articles were assessed on quality and risk of bias. Weighted means of Doppler indices were calculated using a random-effects model. Results In healthy pregnancies, PI and RI decreased from 0.80 (95% CI: 0.70–0.89) and 0.50 (95% CI: 0.47–0.54) in the first trimester to 0.50 (95% CI: 0.45–0.55, p < 0.001) and 0.39 (95% CI: 0.37–0.42, p < 0.001) in the second trimester and to 0.49 (95% CI: 0.44–0.53, p = 0.752) and 0.36 (95% CI: 0.35–0.38, p = 0.037) in the third trimester, respectively. In parallel, PSV altered from 0.22 m/s (95% CI: 0.13–0.30 m/s) to 0.28 m/s (95% CI: 0.17–0.40 m/s, p = 0.377) and to 0.25 m/s (95% CI: 0.20–0.30 m/s, p = 0.560) in the three trimesters. In absence of second and third trimester Doppler data in complicated gestation, only a difference in PI was observed between complicated and healthy pregnancies during the first trimester (1.49 vs 0.80, p < 0.001). Although individual studies have identified differences in PI between SpA located in the central part of the placental bed versus those located at its periphery, this meta-analysis could not confirm this (p = 0.349). Conclusions This review and meta-analysis concludes that an observed decrease of SpA PI and RI from the first towards the second trimester parallels the physiological trophoblast invasion converting SpA during early gestation, a process completed in the midst of the second trimester. Higher PI was found in SpA of complicated pregnancies compared to healthy pregnancies, possibly reflecting suboptimal utero-placental circulation. Longitudinal studies examining comprehensively the predictive value of spiral artery Doppler for complicated pregnancies are yet to be carried out.

scholarly journals Spiral artery blood flow during pregnancy: a systematic review and meta-analysis.

2019 ◽  
Author(s):  
Veronique Schiffer ◽  
Laura Evers ◽  
Sander de Haas ◽  
Chahinda Ghossein ◽  
Salwan Al-Nasiry ◽  
...  
Keyword(s):  
Systematic Review ◽  
Blood Flow ◽  
Meta Analysis ◽  
Resistance Index ◽  
First Trimester ◽  
Trophoblast Invasion ◽  
Cochrane Library ◽  
Second Trimester ◽  
Spiral Artery ◽  
Third Trimester

Abstract Background : Downstream remodeling of the SpA decreases utero-placental resistance drastically, allowing sustained and increased blood flow to the placenta at all circumstances. We systematically evaluated available reports to visualize adaptation of spiral arteries throughout pregnancy by ultra-sonographic measurements and evaluated when this process is completed. Methods : A systematic review and meta-analysis of spiral artery flow (pulsatility index (PI), resistance index (RI) and peak systolic velocity (PSV)) was performed. English articles were obtained from Pubmed, EMBASE and Cochrane Library and included articles were assessed on quality and risk of bias. Weighted means of Doppler indices were calculated using a random-effects model. Results : In healthy pregnancies, PI and RI decreased from 0.75 (95% CI: 0.67-0.83) and 0.49 (95% CI: 0.46-0.53) in the first trimester to 0.52 (95% CI: 0.48-0.56, p=0.003) and 0.40 (95% CI: 0.38-0.42, p=0.080) in the second trimester and to 0.49 (95% CI: 0.44-0.53, p=0.510) and 0.36 (95% CI: 0.35-0.37, p=0.307) in the third trimester, respectively. In parallel, PSV altered from 0.24 m/s (95% CI: 0.17-0.31 m/s) to 0.28 m/s (95% CI: 0.22-0.34 m/s, p=0.377) and to 0.25 m/s (95% CI: 0.21-0.28 m/s, p=0.919) in the three trimesters. In absence of second and third trimester Doppler data in complicated gestation, only a difference in PI was observed between complicated and healthy pregnancies during the first trimester (1.49 vs 0.76, p<0.001). Although individual studies have identified differences in PI between SpA located in the central part of the placental bed versus those located at its periphery, this meta-analysis could not confirm this (p=0.349) . Conclusions : This review and meta-analysis concludes that an observed decrease of SpA PI and RI from the first towards the second trimester parallels the physiological trophoblast invasion converting SpA during early gestation, a process completed in the midst of the second trimester. Higher PI and RI were found in SpA of complicated pregnancies compared to healthy pregnancies, possibly reflecting suboptimal utero-placental circulation. Longitudinal studies examining comprehensively the predictive value of spiral artery Doppler for complicated pregnancies are yet to be carried out.

scholarly journals Does Vitamin D Deficiency in Different Periods of Gestation Have the Same Effect on Preterm Birth? A Systematic Review and Meta-Analysis

2020 ◽  
Author(s):  
bin Yi ◽  
Rui-han Lian ◽  
Ping-an Qi ◽  
Tao Yuan ◽  
Pei-jing Yan ◽  
...  
Keyword(s):  
Systematic Review ◽  
Vitamin D ◽  
Preterm Birth ◽  
Vitamin D Deficiency ◽  
Meta Analysis ◽  
Cochrane Library ◽  
Second Trimester ◽  
Case Control Studies ◽  
Cross Sectional ◽  
Vitamin D Levels

Abstract Background: Current studies suggest that vitamin D deficiency during pregnancy can produce a certain effect for preterm birth, but there is no research showing whether vitamin D deficiency has a consistent effect in different pregnancies; thus, we conducted a systematic review and meta-analysis of 24 observational studies, grouping them according to the gestational age at the time of serum sampling, to investigate whether vitamin D deficiency in different periods of gestation has different effects on preterm birth and to provide an evidence-based basis for pregnant women to measure and supplement vitamin D. Methods: The databases PubMed-Medline, EMBASE, the Cochrane Library, Web of Science, EBSCO, CBM, and CNKI were searched until July 2019. Two researchers independently assessed the eligibility and quality of studies, and STATA 12.0 software was used for meta-analysis. Result: Seven cohort studies, 13 case-control studies, and four cross-sectional studies were included from 2500 articles by inclusion and exclusion criteria. After adjusting for age, race, and other confounding factors, meta-analysis results showed that vitamin D deficiency in the first trimester, the second trimester and the third trimester did not increase the risk of preterm birth (odds ratio (OR) = 1.01, 95% confidence interval (CI) (0.88, 1.16), P = 0.867; OR = 1.12, 95%CI (0.92, 1.37), P = 0.249; OR = 1.05, 95%CI (0.87, 1.27), P = 0.602). However, there was moderate heterogeneity in the study of vitamin D deficiency in the second trimester, and subgroup analysis suggested that vitamin D deficiency in the second trimester may increase the risk of preterm birth (OR = 1.33, 95%CI (1.15, 1.54), P = 0.000). A sensitivity analysis of the second trimester showed that excluding any one study did not significantly change the results. Conclusions: Vitamin D deficiency in early and late pregnancy may not be associated with preterm birth, while vitamin D deficiency in middle pregnancy is likely to have an important effect on preterm birth. Vitamin D levels should be measured in the second trimester of pregnancy, and vitamin D supplements should be provided if necessary.

scholarly journals The Frequency of Vaginal Intercourse During Pregnancy: A Systematic and Meta-Analysis Stud

2018 ◽  
Vol 7 (1) ◽  
pp. 1-9
Author(s):  
Maryam Hasani ◽  
Afsaneh Keramat ◽  
Raziyeh Maasoumi ◽  
Maryam Farjamfar ◽  
Masud Yunesian ◽  
...  
Keyword(s):  
Meta Analysis ◽  
First Trimester ◽  
Sexual Life ◽  
Vaginal Intercourse ◽  
Second Trimester ◽  
Third Trimester ◽  
Mean Frequency ◽  
The Third ◽  
Reference Manager ◽  
The Mean

Objectives: Sexual life may change during pregnancy. Due to negative attitudes toward having sex, unpleasant feeling, and fear of several issues, women might avoid vaginal intercourse during pregnancy. Therefore, the present systematic review aimed to investigate the frequency of vaginal intercourse in pregnancy. Materials and Methods: Comprehensive literature review was conducted to find the relevant articles published (from December 1990 to April 2018) on the issue including observational studies (e.g., cross-sectional and cohort studies) that certainly determined the mean frequency of vaginal sex throughout pregnancy. In this regard, online international databases such as ISI, PubMed, Scopus, Cochrane, and Google Scholar were independently explored and checked by two authors. Duplicate articles were removed by the EndNote X7 Reference Manager. The results were analyzed using RevMan 5.3 software. The P < 0.05 was considered significant. Results: Totally, after excluding the duplicate and irrelevant articles based on having the mean frequency of vaginal intercourse during pregnancy, 13 articles were obtained. The range of vaginal intercourse frequency varied from 6.01 to 21 times every month pre-pregnancy, 3.67-9.87 times monthly in the first trimester, 2.78-7.21 times monthly in the second trimester, and 1.35-5.9 times monthly in the third trimester. Five out of the 13 selected articles reporting the mean and standard deviation were entered the current meta-analysis. The frequency of vaginal intercourse was obtained 7.75 (7.13-8.38) times monthly prior to pregnancy, 4.16 (3.86-4.46) times in the first trimester, 6.37 (5.60-7.14) times monthly in the second trimester, and 1.81 (1.49-2.13) times monthly in the third trimester. Conclusions: Generally, the frequency of vaginal intercourse decreased in the first trimester while increasing in the second trimester. However, a sharp decline was observed between the second and third trimesters of pregnancy.

scholarly journals Plasma volume expansion across healthy pregnancy: a systematic review and meta-analysis of longitudinal studies

2019 ◽  
Author(s):  
Sixtus Aguree ◽  
Alison D. Gernand
Keyword(s):  
Longitudinal Studies ◽  
Plasma Volume ◽  
Volume Expansion ◽  
Meta Analysis ◽  
First Trimester ◽  
Second Trimester ◽  
Third Trimester ◽  
Plasma Volume Expansion ◽  
The Third ◽  
Rate Of Increase

Abstract Background: Plasma volume expansion is an important physiologic change across gestation. High or low expansion has been related to adverse pregnancy outcomes, yet there is a limited understanding of normal/healthy plasma volume expansion. We aimed to evaluate the pattern of plasma volume expansion across healthy pregnancies from longitudinal studies. Methods: We conducted a systematic review and meta-analysis to identify original studies that measured plasma volume in singleton pregnancies of healthy women. Specifically, we included studies that measured plasma volume at least two times across gestation and one time before or after pregnancy in the same women. PubMed, Web of Science, Cochrane, CINAHL, and clinicaltrials.gov databases were searched from the beginning of each database to February 2019. We combined data across studies using a random effects model. Results: Ten observational studies with a total of 347 pregnancies were eligible. Plasma volume increased by 6% (95% CI 3-9) in the first trimester compared to the non-pregnant state. In the second trimester, plasma volume was increased by 18% (95% CI 12-24) in gestational weeks 14-20 and 29% (95% CI 21-36) in weeks 21-27 above the nonpregnant state. In the third trimester, plasma volume was increased by 42% (95% CI 38-46) in weeks 28-34 and 48% (95% CI 44-51) in weeks 35-38. The highest rate of increase occurred in the first half of the second trimester. Included studies were rated from moderate to high quality; 7 out of 10 studies were conducted over 30 years ago. Conclusions: In healthy pregnancies, plasma volume begins to expand in the first trimester, has the steepest rate of increase in the second trimester, and peaks late in the third trimester. The patterns observed from these studies may not reflect the current population, partly due to the changes in BMI over the last several decades. Additional longitudinal studies are needed to better characterize the range of normal plasma volume expansion across maternal characteristics.

scholarly journals Plasma volume expansion across healthy pregnancy: a systematic review and meta-analysis of longitudinal studies

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Sixtus Aguree ◽  
Alison D. Gernand
Keyword(s):  
Longitudinal Studies ◽  
Plasma Volume ◽  
Volume Expansion ◽  
Meta Analysis ◽  
First Trimester ◽  
Second Trimester ◽  
Third Trimester ◽  
Plasma Volume Expansion ◽  
The Third ◽  
Rate Of Increase

Abstract Background Plasma volume expansion is an important physiologic change across gestation. High or low expansion has been related to adverse pregnancy outcomes, yet there is a limited understanding of normal/healthy plasma volume expansion. We aimed to evaluate the pattern of plasma volume expansion across healthy pregnancies from longitudinal studies. Methods We conducted a systematic review and meta-analysis to identify original studies that measured plasma volume in singleton pregnancies of healthy women. Specifically, we included studies that measured plasma volume at least two times across gestation and one time before or after pregnancy in the same women. PubMed, Web of Science, Cochrane, CINAHL, and clinicaltrials.gov databases were searched from the beginning of each database to February 2019. We combined data across studies using a random effects model. Results Ten observational studies with a total of 347 pregnancies were eligible. Plasma volume increased by 6% (95% CI 3–9) in the first trimester compared to the nonpregnant state. In the second trimester, plasma volume was increased by 18% (95% CI 12–24) in gestational weeks 14–20 and 29% (95% CI 21–36) in weeks 21–27 above the nonpregnant state. In the third trimester, plasma volume was increased by 42% (95% CI 38–46) in weeks 28–34 and 48% (95% CI 44–51) in weeks 35–38. The highest rate of increase occurred in the first half of the second trimester. Included studies were rated from moderate to high quality; 7 out of 10 studies were conducted over 30 years ago. Conclusions In healthy pregnancies, plasma volume begins to expand in the first trimester, has the steepest rate of increase in the second trimester, and peaks late in the third trimester. The patterns observed from these studies may not reflect the current population, partly due to the changes in BMI over the last several decades. Additional longitudinal studies are needed to better characterize the range of normal plasma volume expansion across maternal characteristics.

scholarly journals The role of obesity and adipokines in coronary microvascular dysfunction: a systematic review and meta-analysis

2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
M Spezia ◽  
A Bonato ◽  
G De Fortunato ◽  
A Bossi ◽  
M Glauber
Keyword(s):  
Systematic Review ◽  
Blood Flow ◽  
Coronary Flow ◽  
Meta Analysis ◽  
Risk Of Bias ◽  
Cochrane Library ◽  
Flow Reserve ◽  
Increased Risk ◽  
Significant Difference

Abstract Funding Acknowledgements Type of funding sources: None. Background Patients with obesity present structural and functional changes in the heart and in the coronary circulation, which ultimately leads to an increased risk of cardiovascular disease. Obesity is associated with a low chronic state of inflammation which seems to be linked to a compromised coronary vasoreactivity, which is shown to be a forerunner and a long-term predictor of clinically relevant cardiovascular events. Methods A systematic review was performed by searching PubMed, Embase and Cochrane Library database. Selection criteria were applied leading to the inclusion of studies of any level of evidence published in peer-reviewed journals reporting clinical or preclinical results. Relative data were extracted and critically analysed. PRISMA guidelines were applied and risk of bias was assessed, as well as the methodological quality of the included studies. After this assessment, we excluded all the articles with serious risk of bias and/or low quality. Meta-analysis was conducted on the data collected regarding coronary blood flow (CFR) and hyperemic myocardial blood flow (MBF), while for the other parameters a descriptive analysis was performed. Results After applying the described criteria, we included 15 articles on human and animal literature assessed as medium or high quality. The data of 1399 patients were examined, 456 of which with obesity (BMI ≥ 30). A pooled effect size analysis shows that coronary flow reserve (CFR) is significantly reduced in patients with obesity [Random Effect (RE): -47.7%, 95% confidence interval (CI) -80.2% – -15.2%; n = 422]. Increased BMI is associated with reduced CFR. The same trend is found evaluating pharmacological induced stress MBF, which was reduced in patients with obesity [RE: -47.8%, 95% CI -73.7% – -21.8%; n = 409]. Nevertheless, MBF at rest did not show a significant difference in patients with obesity from our analysis [RE: 15%, 95% CI -24% - 53%; n = 409]. Pro-inflammatory adipokines secretion, as leptin and CRP, seems to correlate with a significant decrease of stress-induced MBF and reduced CFR. Conclusions Obesity is associated with a significant higher risk of coronary microvascular disfunction, which is reflected by diminished CFR and stress MBF. Systemic inflammation and the imbalance of adipokines related to obesity has been closely linked to a blunt coronary flow. CMD is a pre-clinical heart conditions that often remains undiagnosed. Further evidence is required to clear out the role of Obesity from a molecular point of view on the coronary endothelium.

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