Maternal abdominal subcutaneous fat thickness as a predictor for adverse pregnancy outcome: a longitudinal cohort study

Evaluating the Adipose Tissue Depth as a Predictor Factor for Gestational Diabetes in Later Pregnancy-A Systematic Review

The increasing prevalence of gestational diabetes mellitus (GDM) requires non-invasive and precise techniques for evaluating the predisposing risk factors such as visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT). According to PRISMA, we developed a systematic review and searched after "visceral adipose tissue AND gestational diabetes" and identified 221 articles on the MEDLINE and Word of Science databases. After assessing them for inclusion criteria and two researchers screened them, 11 relevant articles were included. Although evidence is conflicting, more studies favor using US-determined VAT in GDM prediction. VAT may be more valuable than body mass index or SAT in predicting GDM. VAT can represent an additive factor to the prediction tool of the risk of developing GDM when used in conjunction with other anthropometric or biological parameters or maternal risk factors. US measurements are heterogeneous given different evaluation techniques, cut-off values and inter-operator variation. A significant limitation is the lack of a gold standard to identify GDM confidently. Pregnant women may benefit from early monitoring and preventive care if classified as high risk for GDM early in the gestational period. US-measured VAT during the first trimester of pregnancy seems a valuable and inexpensive screening approach to predict GDM development later in pregnancy, either by itself or if used in conjunction with other clinical and biological parameters.

The role of ultrasonographic adipose tissue thickness measurement in the first trimester in predicting gestational diabetes: a prospective study

BACKGROUND

This prospective observational study aimed to assess the association between maternal abdominal subcutaneous and visceral fat thickness measured with ultrasound scan during the first trimester and the risk of developing gestational diabetes mellitus (GDM).

METHODS

We recruited 43 non-diabetic women with singleton pregnancy between 11 and 14 week of gestation and evaluated ultrasonographic measurements of subcutaneous fat thickness (SFT) and preperitoneal fat (PF) above the umbilicus. During the 2^nd trimester, GDM screening was performed by 75 g two-hour oral glucose tolerance test (OGTT) and diagnosis was made when one or more plasma glucose values meets or exceeds the values indicated by International Association of the Diabetes and Pregnancy Study Groups (IADPSG).

RESULTS

Among the 43 woman, 8 developed GDM (18.6%). Of these 37,5% (N.=3) had been diagnosed with GDM during a previous pregnancy, with a statistically significant correlation (P=0.035). Mean SFT for all patients was significantly higher in the GDM group compared to non-GDM group (27.30±8.78 mm vs. 18.56±9.99 mm; P=0.049). Mean PF for all women showed a statistically significant correlation with GDM (13.27±9.07 mm for non GDM group vs. 23.52±10.24 mm for GDM group; P=0.038).

CONCLUSIONS

Abdominal adiposity, both subcutaneous and visceral, seem to be a suitable predictor of GDM in early pregnancy and it can be easily assessed during a first trimester routine ultrasound, although further studies are needed to evaluate their role in the screening protocols.

Association of body composition in early pregnancy with gestational diabetes mellitus: A meta-analysis

INTRODUCTION

Body composition as dynamic indices constantly changes in pregnancy. The use of body composition indices in the early stages of pregnancy has recently been considered. Therefore, the current meta-analysis study was conducted to investigate the relationship between body composition in the early stages of pregnancy and gestational diabetes.

METHOD

Valid databases searched for papers published from 2010 to December 2021 were based on PRISMA guideline. Newcastle Ottawa was used to assess the quality of the studies. For all analyses, STATA 14.0 was used. Mean difference (MD) of anthropometric indices was calculated between the GDM and Non-GDM groups. Pooled MD was estimated by "Metan" command, and heterogeneity was defined using Cochran's Q test of heterogeneity, and I 2 index was used to quantify heterogeneity.

RESULTS

Finally, 29 studies with a sample size of 56438 met the criteria for entering the meta-analysis. Pooled MD of neck circumference, hip circumference, waist hip ratio, and visceral adipose tissue depth were, respectively, 1.00 cm (95% CI: 0.79 to 1.20) [N = 5; I^2: 0%; p: 0.709], 7.79 cm (95% CI: 2.27 to 13.31) [N = 5; I2: 84.3%; P<0.001], 0.03 (95% CI: 0.02 to 0.04) [N = 9; I2: 89.2%; P<0.001], and 7.74 cm (95% CI: 0.11 to 1.36) [N = 4; I^2: 95.8%; P<0.001].

CONCLUSION

Increased neck circumference, waist circumference, hip circumference, arm circumference, waist to hip ratio, visceral fat depth, subcutaneous fat depth, and short stature increased the possibility of developing gestational diabetes. These indices can accurately, cost-effectively, and affordably assess the occurrence of gestational diabetes, thus preventing many consequences with early detection of gestational diabetes.

Evaluation of ultrasound measurements of abdominal fat for the prediction of gestational diabetes in the first and second trimesters of pregnancy

OBJECTIVE

To evaluate whether ultrasound abdominal fat measurements in the first and second trimesters can predict adverse gestational outcomes, particularly gestational diabetes mellitus (GDM), and identify early patients at higher risk for complications.

METHODS

A prospective cohort study of 126 pregnant women at 11-14 and 20-24 weeks of gestation with normal fasting glucose levels during early pregnancy. From 126 participants with complete data, 13.5% were diagnosed with GDM, based on the cutoffs established for the peripherical blood glucose. Subcutaneous, visceral, and maximum preperitoneal abdominal fat were measured using ultrasound techniques. GDM status was determined by oral glucose tolerance test (OGTT) with 75 g glucose overload, and the following values were considered abnormal: fasting glucose ≥92 mg/dl and/or 1 h after overload ≥180 mg/dl and/or 2 h after overload ≥153 mg/dl. The receiver operator characteristic (ROC) curve was used to determine the optimal threshold to predict GDM.

RESULTS

Maximum preperitoneal fat measurement was predictive of GDM, and subcutaneous and visceral abdominal fat measurements did not show significant differences in the prediction of GDM. According to the ROC curve, a threshold of 45.25 mm of preperitoneal fat was identified as the optimal cutoff point, with 87% sensitivity and 41% specificity to predict GDM. The raw and adjusted odds ratios for age and pre-pregnancy body mass index were 0.730 (95% confidence interval [CI], 0.561-0.900) and 0.777 (95% CI, 0.623-0.931), respectively.

CONCLUSION

The use of a 45.25 mm threshold for maximum preperitoneal fat, measured by ultrasound to predict the risk of GDM, appears to be a feasible, inexpensive, and practical alternative to incorporate into clinical practice during the first trimester of pregnancy.

Predictors of Adverse Pregnancy Outcomes in Pregnant Women Living with Obesity: A Systematic Review

Obesity is a well-recognized risk factor for pregnancy complications. Most studies to date are in large cohorts, with results presented in a way that assumes all women living with obesity are at equal risk. This study investigates which women living with obesity are at higher risk of specific pregnancy complications. A systematic search of MEDLINE and Embase identified 7894 prospective or retrospective cohort studies exploring predictors of adverse outcomes among pregnant women living with obesity. Following screening, 61 studies were deemed eligible. Studies were selected if the effects of exposure to any predictor amongst pregnant women living with obesity could be collected. Maternal characteristics assessed for association with adverse outcomes included maternal age, race/ethnicity, maternal height, mode of conception, complement activation factors, and history of various comorbidities/procedures. Gestational diabetes mellitus was the most studied outcome (n = 32), followed by preterm birth (n = 29), preeclampsia (n = 27), low birthweight infants (n = 20), small for gestational age newborns (n = 12), and stillbirth (n = 7). This review identified important characteristics that should be considered during the screening and follow-up sessions of pregnant women living with obesity, including pre-existing type 1 diabetes, maternal age < 20 years or ≥35 years, non-White ethnicity, abdominal adiposity obesity, and history of bariatric surgery.

Effects of obesity indices/GDM on the pregnancy outcomes in Chinese women: A retrospective cohort study

OBJECTIVE

To analyze pregnancy complications and outcomes of mothers with obesity or gestational diabetes mellitus (GDM).

METHODS

15065 mothers were categorized into four and three groups by pre-pregnancy body mass index (preBMI) and abdominal circumference (AC), respectively, or divided into GDM or non-GDM groups. Logistic regression analysis was utilized to identify independent factors associated with pregnancy complications and outcomes.

RESULTS

The overweight and obesity groups accounted for 16.0% and 4.0% of the total population, respectively. GDM incidence rate was 12.3%. The overweight and obesity groups (pre-pregnancy body mass index [preBMI] ≥ 24 kg/m²) were at higher risks for GDM, hypertensive disorders of pregnancy (HDP), gestational proteinuria, postpartum hemorrhage, preterm delivery, fetal malformation or stillbirth, neonatal asphyxia, large for gestational age (LGA), shoulder dystocia, and increased cesarean section rate. Similar results were obtained with AC grouping. GDM pregnant women had higher risks of HDP, preterm delivery, small for gestational age (SGA), LGA, and increased cesarean section rate.

CONCLUSION

People with obesity had a higher risk of adverse pregnancy outcomes. The recommended preBMI is 19.2-22.7 kg/m². The recommended AC at 11-13⁺⁶ gestational weeks is 74.0-84.0 cm, and that value in normal preBMI is 74.0-82.0 cm.

Ultrasound estimated subcutaneous and visceral adipose tissue thicknesses and risk of pre-eclampsia

Early identification of high-risk pregnancies enables identification of those who would benefit from aspirin prophylaxis and increased surveillance for pre-eclampsia. A high body mass index (BMI) is a well-known predictor for pre-eclampsia. However, if abdominal adipose tissue distribution is associated with pre-eclampsia is limited investigated. Subcutaneous adipose tissue (SAT) thickness and visceral adipose tissue (VAT) thickness were measured by ultrasound on 3777 women at around 18 gestational weeks. SAT thickness was measured from the skin to linea alba and VAT from linea alba to the anterior aortic wall. The risk of developing pre-eclampsia (de novo hypertension at ≥ 20 gestational weeks in combination with proteinuria) was evaluated by logistic regression and expressed as odds ratio (OR) with 95% confidence intervals (CI). The risk of pre-eclampsia increased by 79% for every cm in SAT thickness (OR 1.79; 95% CI 1.48–2.17) and by 23% for every cm VAT thickness (OR 1.23; 95% CI 1.11–1.35). After adjustment for maternal age, parity, BMI, smoking and country of birth, the association between SAT thickness and pre-eclampsia remained (AOR 1.35; 95% CI 1.02–1.79). Greater SAT thickness measured with second trimester ultrasound is associated with increased risk of developing pre-eclampsia. The measurement may improve prediction models for pre-eclampsia.

The association of general obesity, central obesity and visceral body fat with the risk of gestational diabetes mellitus: Evidence from a systematic review and meta-analysis

BACKGROUND

Studies consistently reported that general obesity predicts gestational diabetes mellitus (GDM). However, whether other phenotypes of obesity such as central obesity and visceral adiposity might have differential associations as risk factors of GDM are less known. The objective of this study was to investigate the association of all these obesity phenotypes in developing GDM.

METHODS

PubMed, CINHAL, Embase, Scopus, Google Scholar and Web of Science were searched. Full-text research articles published in English from 1985 to February 2020 with cohort and cross-sectional studies design and reported an association between obesity and GDM were included. Case-control studies, case reports, conference abstract, women with previous metabolic disorders and articles considered general obesity only were excluded. A bias adjusted-quality effect meta-analysis was conducted to evaluate the association of these obesity phenotypes and GDM risk.

RESULTS

Twenty studies met the inclusion criteria representing data of ∼50 thousand women at the reproductive age with ∼7% prevalence of GDM. Meta-analysis of 14 datasets revealed that the three types of obesity were significantly associated with an increased risk of GDM. In addition, visceral adiposity was a stronger risk factor for GDM than other obesity phenotypes (odd ratio = 3.25, 95% confidence interval = 2.01-5.26) versus (odd ratio = 2.73, 95% confidence interval = 2.20-3.38) for general obesity and (odd ratio = 2.53, 95% confidence interval = 2.04-3.14) for central obesity.

CONCLUSION

The findings of this study suggest that general obesity, central obesity and visceral body fat were associated with an increased risk of GDM. Furthermore, the association with maternal visceral adiposity was more robust compared to general obesity and central obesity.

Towards Transabdominal Functional Photoacoustic Imaging of the Placenta: Improvement in Imaging Depth Through Optimization of Light Delivery

Functional photoacoustic imaging of the placenta could provide an innovative tool to diagnose preeclampsia, monitor fetal growth restriction, and determine the developmental impacts of gestational diabetes. However, transabdominal photoacoustic imaging is limited in imaging depth due to the tissue's scattering and absorption of light. The aim of this paper was to investigate the impact of geometry and wavelength on transabdominal light delivery. Our methods included the development of a multilayer model of the abdominal tissue and simulation of the light propagation using Monte Carlo methods. A bifurcated light source with varying incident angle of light, distance between light beams, and beam area was simulated to analyze the effect of light delivery geometry on the fluence distribution at depth. The impact of wavelength and the effects of variable thicknesses of adipose tissue and muscle were also studied. Our results showed that the beam area plays a major role in improving the delivery of light to deep tissue, in comparison to light incidence angle or distance between the bifurcated fibers. Longer wavelengths, with incident fluence at the maximum permissible exposure limit, also increases fluence within deeper tissue. We validated our simulations using a commercially available light delivery system and ex vivo human placental tissue. Additionally, we compared our optimized light delivery to a commercially available light delivery system, and conclude that our optimized geometry could improve imaging depth more than 1.6×, bringing the imaging depth to within the needed range for transabdominal imaging of the human placenta.

Associations of ultrasound estimated early mid pregnancy visceral and subcutaneous fat depths and early pregnancy BMI with adverse neonatal outcomes

This study investigated whether maternal central adiposity and body mass index (BMI) were associated with neonatal hypoglycemia and adverse neonatal outcomes. A cohort study was performed at Uppsala University Hospital, Sweden, between 2015 and 2018. Visceral and subcutaneous fat depths were measured by ultrasound at the early second-trimester anomaly scan in 2771 women giving birth to singleton infants. Body mass index was assessed in early pregnancy. Logistic regression models were performed. Adjustments were made for age, BMI (not in model with BMI as exposure), smoking, maternal country of birth, and parity. Outcomes were neonatal hypoglycemia (blood glucose concentration < 2.6 mmol/l), a composite of adverse neonatal outcomes (Apgar < 7 at 5 min of age, or umbilical artery pH ≤ 7.0, or admission to neonatal intensive care unit), and the components of the composite outcome. Visceral and subcutaneous fat depths measured by ultrasound in early mid pregnancy were not associated with any of the outcomes in adjusted analyses. For every unit increase in BMI, the likelihood of neonatal hypoglycemia increased by 5% (aOR 1.05, 95% CI 1.01–1.10), the composite outcome by 5% (aOR 1.05, 95% CI 1.01–1.08), and admission to neonatal intensive care unit by 6% (aOR 1.06, 95% CI 1.02–1.10).

Association of maternal central adiposity measured by ultrasound in early mid pregnancy with infant birth size

We sought to investigate whether early mid pregnancy visceral and subcutaneous fat depths measured by ultrasound were associated with infant birth size, independent of early pregnancy BMI. A cohort study was performed at Uppsala University Hospital, Sweden, between 2015–2018. Visceral and subcutaneous fat depths were measured at the early second-trimester anomaly scan in 2498 women, giving birth to singleton, term infants. Primary outcomes were birthweight and LGA (birthweight standard deviation score > 90th percentile in the cohort). Linear and logistic regression models were used, adjusted for BMI, age, smoking, parity, maternal country of birth, gestational age and infant sex. A 5-mm increase in visceral fat depth was associated with an increase in birthweight of 8.3 g [95% confidence interval (CI) 2.5 − 14.1 g], after adjustments, and a 6% increase in the adjusted odds of having an infant born LGA (OR 1.06, CI 1.02–1.11). There was no association between subcutaneous fat depth and birthweight or LGA after covariate adjustments. Hence, visceral fat depth measured by ultrasound in early mid pregnancy was associated with excessive fetal growth, independent of early pregnancy BMI, and may be useful in models for predicting LGA infants.

Impact of maternal central adiposity on infant anthropometry and perinatal morbidity: A systematic review

Overweight and obesity during pregnancy are risk factors for a large number of perinatal complications, both for the mother and the infant. Risk stratification and early interventions are therefore highly clinically important to minimize future complications. Currently, body mass index (BMI) in early pregnancy is used for risk stratification of pregnant women, but a disadvantage of BMI is that it does not distinguish muscle from fat tissue and central from peripheral adiposity. Maternal fat distribution is suggested to be a better predictor than BMI of obesity-related adverse pregnancy outcomes, with central adiposity posing a greater risk than peripheral subcutaneous fat. With this study, we aimed to systematically review the evidence of what impact maternal central adiposity in early to mid-pregnancy or at most 365 days prior to conception has on infant anthropometry and perinatal morbidity.

The databases PubMed/MEDLINE, Web of Science Core Collection, CINAHL, SCOPUS, Clinical Trials, and Open Grey were searched from inception until November 2019. Eligible studies assessed the association between maternal central adiposity, in early to mid-pregnancy or at most 365 days prior to conception, and any of the following infant outcomes: preterm delivery (< 37 weeks of gestation), birthweight, macrosomia, large for gestational age, congenital malformations, hypoglycemia, hyperbilirubinemia, care at neonatal intensive care unit, and death. Two authors independently screened titles and abstracts, read the included full-text studies, and extracted data. The Newcastle-Ottawa Quality Assessment Scale for cohort studies was used to evaluate the quality of and risk of bias in the studies.

A total of 720 records were identified, 20 full-text studies assessed for eligibility, and 10 cohort studies included in the review. The results suggest that central adiposity in early to mid-pregnancy or at most 365 days prior to conception may contribute to increased birthweight and increased likelihood of delivery by cesarean section. There is also some evidence of associations between central adiposity and preterm delivery (< 37 weeks of gestation), and admission to neonatal intensive care unit. A meta-analysis was not possible to perform due to substantial heterogeneity among the included studies regarding the exposure, outcome, and statistical methods used.

Hence, central adiposity in early to mid-pregnancy or at most 365 days prior to conception could be a possible risk marker in addition to BMI for risk stratification of pregnant women. However, since the topic is only scarcely researched, and the results not unanimous, more studies are needed to further clarify the associations between maternal central adiposity and adverse neonatal complications, before any altered recommendations of guidelines could be made. To enable a future meta-analysis, studies using similar methods for central adiposity assessment,and similar outcome measures, are required.

Ultrasound evaluation of subcutaneous and visceral abdominal fat as a predictor of gestational diabetes mellitus: a systematic review

Objective: Studies of subcutaneous and visceral abdominal fat thickness evaluated by ultrasound as a predictor of gestational diabetes mellitus (GDM) have been published, but the best technique and standardization are unknown. To identify, critically evaluate, and analyze studies using subcutaneous and visceral abdominal fat as a model for predicting GDM in the first and second trimesters of pregnancy and evaluate their methodological quality.Methods: PubMed, Scopus, and Web of Science databases were searched from May to July 2019. We included studies of any sample size performed for any duration and in any configuration. Model development and validation studies were eligible for inclusion. Two authors independently performed the eligibility assessment of the studies by reviewing the titles and abstracts. Data on study design, gestational age, diagnostic criteria for GDM, device, ultrasound fat measurement technique, and cutoff point for GDM prediction were extracted.Results: The electronic search resulted in 1331 articles, of which 14 were eligible for systematic review. Different criteria for diagnosing GDM and fat measurement techniques were used. The cutoff point for subcutaneous, visceral, and total abdominal fat for predicting GDM in the first and second trimesters varied between the studies.Conclusion: No study validated the model for predicting GDM using subcutaneous and visceral abdominal fat measurements. External validation studies are recommended to improve the generalization of this GDM predictor in clinical practice.

Prospective observational investigation of body habitus measurements and relationship to epidural depth in term pregnant women

BACKGROUND

High body mass index (BMI) can predict difficult neuraxial block; however, fat distribution may also be important. The primary study aim was to identify body habitus and fat distribution measurements that correlated with ultrasound measured epidural depth. We hypothesized that measurements such as midarm and subscapular fatpad thicknesses and length of cervical spine may correlate better with ultrasound measured epidural depth than a global measure of BMI.

METHODS

Prospective IRB approved study of term pregnant women requiring neuraxial block. We measured height, weight (BMI, kg/m² ), subscapular, midarm fatpad thickness (digital caliper, mm), vertebral column length (C7 to sacral hiatus, cm) and epidural depth (ultrasound, mm). Four experts assessed photographs to assign anticipated difficult neuraxial block in sitting and lateral positions (5-point Likert scale, 1 = very easy, 5 = very difficult).

RESULTS

In all, 131 women completed body habitus measurements. Measured mean (standard deviation) BMI was 30.3 (5.4) kg/m² . Measured BMI, subscapular fatpad and midarm fatpad thickness were significantly correlated with ultrasound depth to epidural space (R² 0.733, 0.626 and 0.633, respectively, P < .0001) but vertebral column length was not. The experts had a high level of agreement (Cronbach's alpha >0.7) for assessment of anticipated difficult block in the sitting and lateral positions; however, anticipated difficult block was not correlated with epidural depth measured by ultrasound for sitting position, R²  = -0.015, P = .87; and lateral position, R²  = -0.087, P = .33.

CONCLUSIONS

Measurements of body habitus and fat distribution were no better than measured BMI to anticipate greater ultrasound measured depth to epidural space. Clinical trial number: Non-interventional observational study, not registered.

Maternal Adipose Tissue Expansion, A Missing Link in the Prediction of Birth Weight Centile

CONTEXT

Maternal body mass index (BMI) is associated with increased birth weight but does not explain all the variance in fetal adiposity.

OBJECTIVE

To assess the contribution of maternal body fat distribution to offspring birth weight and adiposity.

DESIGN

Longitudinal study throughout gestation and at delivery.

SETTING

Women recruited at 12 weeks of gestation and followed up at 26 and 36 weeks. Cord blood was collected at delivery.

PATIENTS

Pregnant women (n = 45) with BMI 18.0 to 46.3 kg/m2 and healthy pregnancy outcome.

METHODS

Maternal first trimester abdominal subcutaneous and visceral adipose tissue thickness (SAT and VAT) was assessed by ultrasound.

MAIN OUTCOME MEASURES

Maternal body fat distribution, maternal and cord plasma glucose and lipid concentrations, placental weight, birth weight, and fetal adiposity assessed by cord blood leptin.

RESULTS

VAT was the only anthropometric measure independently associated with birth weight centile (r2 adjusted 15.8%, P = .002). BMI was associated with trimester 2 and trimesters 1 through 3 area under the curve (AUC) glucose and insulin resistance (Homeostatic Model Assessment). SAT alone predicted trimester 2 lipoprotein lipase (LPL) mass (a marker of adipocyte insulin sensitivity) (11.3%, P = .017). VAT was associated with fetal triglyceride (9.3%, P = .047). Placental weight was the only independent predictor of fetal adiposity (48%, P < .001). Maternal trimester 2 and AUC LPL were inversely associated with fetal adiposity (r = -0.69, P = .001 and r = -0.58, P = .006, respectively).

CONCLUSIONS

Maternal VAT provides additional information to BMI for prediction of birth weight. VAT may be a marker of reduced SAT expansion and increased availability of maternal fatty acids for placental transport.

Relationship between Maternal Central Obesity and the Risk of Gestational Diabetes Mellitus: A Systematic Review and Meta-Analysis of Cohort Studies

OBJECTIVE

Nowadays, body mass index (BMI) is used to evaluate the risk stratification of obesity-related pregnancy complications in clinics. However, BMI cannot reflect fat distribution or the proportion of adipose to nonadipose tissue. The objective of this study is to evaluate the association of maternal first or second trimester central obesity with the risk of GDM. Research Design and Methods. We searched in PubMed, Embase, and Web of Science for English-language medical literature published up to 12 May 2019. Cohort studies were only included in the search. Abdominal subcutaneous fat thickness, waist circumference, waist-hip ratio or body fat distribution were elected as measures of maternal central obesity, and all diagnostic criteria for GDM were accepted. The random effect meta-analysis was performed to evaluate the relationship between central obesity and the risk of GDM.

RESULTS

A total of 11 cohort studies with an overall sample size of 27,675 women and 2,226 patients with GDM were included in the analysis. The summary estimate of GDM risk in the central obesity pregnant women was 2.76 (95% confidence interval [CI]: 2.35-3.26) using the adjusted odds ratio (OR). The degree of heterogeneity among the studies was low (I ² = 14.4, P = 0.307). The subgroup analyses showed that heterogeneity was affected by selected study characteristics (methods of exposure and trimesters). After adjusting for potential confounds, the OR of adjusted BMI was significant (OR = 3.07, 95% CI: 2.35-4.00).

CONCLUSIONS

Our findings indicate that the risk of GDM was positively associated with maternal central obesity.

Maternal abdominal subcutaneous fat thickness as a simple predictor for gestational diabetes mellitus

Background To date, only a limited number of studies have evaluated the importance of abdominal subcutaneous fat thickness (ASFT) on gestational diabetes mellitus (GDM) screening. The aim of this study was to investigate the effectiveness of ASFT measurement during routine obstetric ultrasound performed between 24 and 28 weeks of gestation in predicting cases with GDM. Methods This prospective comparative study was conducted on 50 cases with GDM and 50 cases without GDM in the GDM screening program at 24-28 gestational weeks between January 2018 and May 2018. The most accurate ASFT cut-off point values were determined for the prediction of cases with GDM by performing receiver operator characteristic (ROC) curve analysis. Results The ASFT was higher in those with GDM compared to those without GDM (P < 0.05). For an ASFT cut-off point value of 18.1 mm for the prediction of cases with GDM, the sensitivity, specificity, negative and positive predictive values were 72.0%, 60.0%, 64.2% and 68.1%, respectively. The risk of GDM increased 3.86-fold in those with ASFT level >18.1 mm (P = 0.001). Conclusion The ASFT value measured by routine obstetric ultrasound performed at 24-28 weeks of gestation was found to be significantly higher in patients with GDM in comparison to those without GDM. However, further multi-centered and comprehensive prospective studies are required to better demonstrate this relationship.

Effects of central obesity on maternal complications in Korean women of reproductive age

BACKGROUND

Considering the obesity-related complications in pregnancy and during delivery, prepregnancy central obesity may also affect pregnancy-related complications. This study aimed to assess the relationship between prepregnancy central obesity and adverse maternal outcomes in Korean women, by using the Korean National Health Insurance Service (NHIS) cohort.

METHODS

In this population-based retrospective cohort study, we used data from the NHIS database, which contains information of health-care utilisation, diagnosis and prescription, and mortality for almost the whole Korean population, together with data from the NHIS health checkup database from 2005 to 2015. The NHIS health checkup data (645-280 days before childbirth) of mothers who had deliveries (total, 783,406 deliveries) from 2006 to 2015 were collected. For maternal adverse outcome data, we searched for diagnoses of maternal complications made during the period of 280 days before each delivery. The odds for maternal complications according to 8 body mass index (BMI) and 10 waist circumference (WC) categories were analysed using logistic regression.

RESULTS

The incidence rates of eclampsia/preeclampsia, caesarean section, multiple gestation, and polycystic ovary syndrome (PCOS) increased according to the increase of BMI and WC. In contrast, the incidence rate of premature rupture of membrane (PROM) was inversely correlated with BMI and WC. In the low BMI (<17.5 and 17.5-19.9 kg/m²) and low WC (<60 and 60.0-64.0 cm) groups, the odds of threatened abortion were elevated.

CONCLUSION

Prepregnancy WC was closely linked to some maternal complications, including eclampsia/preeclampsia, cesarean section, PCOS, and PROM, in a manner similar to prepregnancy BMI.

Evidence of human milk oligosaccharides in maternal circulation already during pregnancy: a pilot study

Human milk oligosaccharides (HMOs) are bioactive glycans linked with health benefits to both the breast-fed infant and lactating mother. We hypothesized that HMOs are present before lactation, already during pregnancy, and are influenced by maternal body composition. In a pilot study, we investigated individual and temporal variations in HMO composition and concentration in maternal serum at gestational weeks 10-14 ( visit 1), 20-24 ( visit 2), and 30-35 (visit 3) (V1, V2, and V3, respectively) and associations with maternal body composition. HMOs were quantified by HPLC and confirmed by enzymatic digest and mass spectrometry. Associations of maternal prepregnancy body mass index (BMI), subcutaneous adipose tissue (SAT) thickness, and adipokines with absolute and relative HMO concentrations were analyzed by Spearman correlation. We identified 16 HMOs and 2 oligosaccharides not common to human milk. HMO concentration and composition varied with gestational age and secretor status. HMO concentration increased with gestational age and changed from a predominantly sialylated profile at V1 to a more balanced fucosylated-to-sialylated ratio at V3, mostly due to a profound increase in 2'-fucosyllactose (2'-FL), reflecting secretor phenotype. In secretor-positive women, BMI was negatively correlated with 2'-FL at V2. SAT at V1 and V2 were strongly negatively correlated with 2'-FL concentrations. This pilot study shows that prenatal HMOs are present in maternal serum, suggesting roles for HMOs already during pregnancy. Our result that maternal body composition is associated with prenatal HMOs might indicate that maternal metabolism modulates HMO composition with unknown implications for maternal and fetal health already during pregnancy.

Increased maternal abdominal subcutaneous fat thickness and body mass index are associated with increased cesarean delivery: A prospective cohort study

INTRODUCTION

Early pregnancy body mass index (BMI) is known to predict adverse pregnancy outcomes but does not account for body fat distribution. This study aimed to determine prospectively whether maternal abdominal subcutaneous fat thickness (SCFT) measured by ultrasound at the fetal morphology scan is a better predictor than BMI of mode of delivery and other pregnancy outcomes.

MATERIAL AND METHODS

This was a prospective cohort study of women delivering singleton neonates at a tertiary public hospital. Women were included if they had appropriate images at the routine fetal anomaly ultrasound scan and delivered in the facility. The primary outcome was mode of delivery categorized as cesarean section or vaginal delivery. The relation between maternal SCFT and BMI was described using the Pearson correlation coefficient. The association of maternal abdominal SCFT BMI at booking-in was compared with pregnancy outcomes using univariate linear and logistic regression.

RESULTS

SCFT and BMI were obtained for 997 women. The median (interquartile range) SCFT was 15.3 mm (12.8-19.6) and median (interquartile range) BMI 24.3 kg/m² (21.7-28.3). Maternal abdominal SCFT and BMI were highly correlated (R²  = 0.55). Both were significantly associated with cesarean delivery: SCFT per 5 mm (odds ratio [OR] 1.32, 95% confidence interval (CI) 1.18-1.48; BMI per 5 kg/m² OR 1.29, 95% CI 1.15-1.44.

CONCLUSIONS

Maternal abdominal SCFT and BMI were both significantly associated with cesarean delivery and other outcomes. More research is needed to define the strengths of maternal SCFT in predicting pregnancy outcomes.

Relationship maternal subcutaneous adipose tissue thickness and development of gestational diabetes mellitus

Objective

We investigated whether the ultrasonographic measurement of maternal subcutaneous adipose tissue (SAT) thickness in the second trimester played a role in predicting gestational diabetes.

Materials and methods

This was a prospective cross-sectional study in which 223 women were classified as healthy (n = 177) or as gestational diabetes (n = 46) on the basis of a negative or positive two-step oral Glucose Challenge Test (GCT), respectively. The depth of the abdominal SAT was evaluated by two-dimensional ultrasonography. Body mass index (BMI), waist circumference (WC), and waist/hip ratio were determined.

Results

There was a positive strong significant correlation between a 50-g GCT level and BMI, WC, and SAT thickness (p < 0.001). Receiver-operating characteristic curve analysis showed SAT thickness above 16.75 mm predicted gestational diabetes mellitus (GDM) with a sensitivity of 71.7%, a specificity of 57.1%, a positive predictive value of 32.3%, and a negative predictive value of 87.6%. There was a good correlation between SAT, BMI, and WC.

Conclusion

Increased SAT, BMI, and WC measurements may be helpful in predicting the risk of the development of GDM in pregnant women.

Increasing body mass index and abdominal subcutaneous fat thickness are associated with increased skin-to-epidural space distance in pregnant women

BACKGROUND

Body mass index does not indicate the distribution of adipose tissue. Central adiposity may be measured using ultrasound measurement of subcutaneous fat thickness. This study determined if the abdominal subcutaneous fat thickness measured correlated with skin-to-epidural space distance at delivery, and compared this with the booking body mass index.

METHODS

We analysed a sub-set of participants from a single-centre, prospective cohort study that assessed the relationship between subcutaneous fat thickness and maternity outcomes. Abdominal subcutaneous fat thickness measurements were obtained during the routine fetal anomaly scan. The skin-to-epidural space distance was obtained in those having epidural or combined spinal-epidural analgesia. Linear regression was used to test for strength of association and adjusted R² values calculated to determine if subcutaneous fat thickness or body mass index was more strongly associated with skin-to-epidural space distance.

RESULTS

The 463 women had a median (IQR) booking body mass index of 25.0 kg/m² (21.8-29.3) and subcutaneous fat thickness of 16.2 mm (13.0-21.0). The median (IQR) skin-to-epidural space distance was 5.0 cm (4.5-6.0). Both parameters significantly correlated with skin-to-epidural space distance (r=0.53 and 0.68 respectively, P <0.001). Adjusted linear regression coefficient (95% CI) for subcutaneous fat thickness was 0.09 (0.08 to 0.11), R²=0.30 and for body mass index 0.12 (0.11 to 0.13), R²=0.47.

CONCLUSIONS

Booking body mass index had a stronger relationship with skin-to- epidural space distance at delivery than subcutaneous fat thickness, explaining 47% of the variation in the skin-to-epidural distance.

Linear sound attenuation model for assessing external stimuli in prenatal period

The popularization of acoustic stimulation during the prenatal period encourages the analysis of sounds reaching the inside of the uterus. To assess the distortion of any sound stimuli, a mathematical model of attenuation has to be used. In this paper a mathematical model is proposed on the basis of data from a physical model. The physical model consisted of muscle slices of two different thicknesses placed in a tank filled with water. The amplitudes of sinusoidal waves between 160 and 2000 Hz were measured under the water surface. Using the collected data, a linear mathematical model of sound attenuation on the way to the fetal ear was created. The results indicated a rise in the amount of sound attenuation for increasing frequencies. Analysis of slope coefficients for two muscle thicknesses revealed that there is no significant difference between attenuation by the thinner and the thicker tissue. Finally, the model was verified with data obtained during experiments on animals. The proposed model of the sound transmission allowed assessment of the attenuation by a soft tissue. It reveals changes in the sound reaching fetal ears, which can make acoustic stimulation different than what is heard in postnatal life. The model can be used to simulate the distortion of any sound which is proposed to prenatal stimulation and to assess its quality.

How to best assess abdominal obesity

PURPOSE OF REVIEW

Abdominal obesity, especially the increase of visceral adipose tissue (VAT), is closely associated with increased mortality related to cardiovascular disease, diabetes, and fatty liver disease. This review provides an overview of the recent advances for abdominal obesity measurement.

RECENT FINDINGS

Compared to simple waist circumference, emerging three-dimensional (3D) body-scanning techniques also measure abdominal volume and shape. Abdominal dimension measures have been implemented in bioelectrical impedance analysis to improve accuracy when estimating VAT. Geometrical models have been applied in ultrasound to convert depth measurement into VAT area. Only computed tomography (CT) and MRI can provide direct measures of VAT. Recent advances in imaging allow for evaluating functional aspects of abdominal fat such as brown adipose tissue and fatty acid composition.

SUMMARY

Waist circumference is a simple, inexpensive method to measure abdominal obesity. CT and MRI are reference methods for measuring VAT. Further studies are needed to establish the accuracy for dual-energy X-ray absorptiometry in estimating longitudinal changes of VAT. Further studies are needed to establish whether bioelectrical impedance analysis, ultrasound, or 3D body scanning is consistently superior to waist circumference in estimating VAT in different populations.

Anthropometric and ultrasound measures of maternal adiposity in the first trimester of pregnancy

Aim

Estimations of central adiposity in pregnancy is a difficult undertaking due to physiological changes that occur in the body. Therefore, the value of some anthropometric measures particularly in pregnancy, such as body mass index (BMI), waist and hip measures are in doubt. The aim was to compare ultrasound (US) measured abdominal subcutaneous fat (USSFT) with other simple anthropometric methods for obesity assessment, evaluating these measures in pregnancy.

Method

Recruited from a larger study, anthropometric measurements were performed between 11-14 weeks' gestation on 575 women. Measuring height, weight, hip, waist circumference, skin-folds of the triceps, thigh and supra-iliac and USSFT. Percentage maternal fat mass was calculated using skin-fold measures. Correlations of these measures were performed to gauge relationships.

Results

The anthropometric measures demonstrated good correlation (0.54-0.93) between individual adipose measures skin-folds, waist, hip, waist to height ratio (WSR) and USSFT with BMI, percentage fat mass and weight. USSFT correlated well with all anthropometric measures (0.54-0.73) correlating best with waist, WSR, BMI and weight. Waist/hip ratio demonstrated a poor correlation with USSFT, BMI, percentage fat mass and weight (0.3-0.41). Mean anthropometric measures were stratified across BMI categories describing adiposity distribution.

Conclusion

USSFT correlates well with most anthropometric measures in early pregnancy. Limitations of the gravid uterus on waist measurements, hydration and compressibility of skin-fold measures and pregnancy influences on weight and BMI assessments could be overcome using US measures. There is a potential for post hoc evaluation using US for pregnancy complications. Maternal research could benefit from a more accurate measure of adiposity.

Prediction of Gestational Diabetes Mellitus in Pregnant Korean Women Based on Abdominal Subcutaneous Fat Thickness as Measured by Ultrasonography

BACKGROUND

This study was performed to verify the correlation between abdominal subcutaneous fat thickness (ASFT) measured by ultrasonography (US) during the first trimester of pregnancy and gestational diabetes mellitus (GDM) of the second trimester in Korean women and to establish a standard of ASFT for predicting GDM.

METHODS

A total of 333 singleton pregnant women participated in this study. Their ASFT was measured by US during the 10⁺⁶ to 13⁺⁶ weeks of pregnancy; then a GDM confirmatory test (100 g oral glucose tolerance test) was conducted during the 24 to 28 week period of pregnancy. Based on the GDM tests, comparative analyses of the ages of the subjects, pre-pregnancy body mass index (BMI), and weight gain during pregnancy were conducted.

RESULTS

The ages of the subjects and weight gains during pregnancy were not correlated to the GDM of the second trimester of pregnancy, but the pre-pregnancy BMIs (22±3.3 kg/m²) and the ASFT (1.9±0.5 cm) measurements between the control group and subjects during the first trimester of pregnancy were found to show significant differences (P<0.001). The cut-off value of the ASFT for predicting GDM was determined to be 2.4 cm (area under the curve=0.90, sensitivity 75.61%, specificity 91.78%, P<0.001). The odds ratio was 2.91 (95% confidence interval, 1.07 to 7.92; P=0.034), which was higher than the 2.4 cm ASFT.

CONCLUSION

It was determined that ASFT as measured by US during the first trimester of pregnancy can be used to predict the risk of developing GDM during the second trimester of pregnancy and for prognosis.

Interpregnancy weight change and adverse maternal outcomes: a retrospective cohort study

PURPOSE

Examine associations between interpregnancy body mass index (BMI) change (difference in the pre-pregnancy BMIs of two consecutive pregnancies) and gestational diabetes mellitus (GDM), pre-eclampsia (PE), gestational hypertension (GHtn), primary cesarean delivery, and vaginal birth after cesarean delivery (VBAC).

METHODS

Modified Poisson regression models estimated adjusted associations.

RESULTS

Every 1-unit increase in interpregnancy BMI increased risks of GDM (relative risk [RR]: 1.09; 95% confidence interval [CI], 1.07-1.11), PE (RR: 1.06; 95% CI, 1.04-1.09), GHtn (RR: 1.08; 95% CI, 1.06-1.10), and primary cesarean delivery (RR: 1.03; 95% CI, 1.01-1.05) and decreased the risk of a successful VBAC (RR: 0.98; 95% CI: 0.97-0.997) in the second pregnancy. A BMI increase of ≥3 units increased risks of GDM (RR: 1.71, 95% CI, 1.52-1.93), PE (RR: 1.60, 95% CI, 1.33-1.94), GHtn (RR: 1.66, 95% CI, 1.42-1.94), and primary cesarean delivery (RR: 1.29, 95% CI, 1.12-1.49) and decreased the risk of a successful VBAC (RR: 0.89; 95% CI, 0.80-0.99) compared to women with interpregnancy BMI change within -1 and +1 unit. GDM was also increased among women increasing their BMI by ≥2 but <3 units (RR: 1.40; 95% CI, 1.21-1.61) and among those gaining ≥1 but <2 units (RR: 1.23; 95% CI, 1.08-1.40).

CONCLUSION

An interpregnancy BMI increase of ≥3 units is associated with an increased risk of all outcomes. These findings emphasize the importance of interpregnancy weight management.

The mutual effect of pre-pregnancy body mass index, waist circumference and gestational weight gain on obesity-related adverse pregnancy outcomes: A birth cohort study

OBJECTIVE

The aim of this study was to examine the mutual effect of pre-pregnancy body mass index (BMI), waist circumference (WC) and gestational weight gain (GWG) on obesity-related adverse pregnancy outcomes.

METHODS

This birth cohort study was conducted in three Streets in Changsha, China, including a total of 976 mother-child pairs. All data was collected within 15 days after deliveries from a self-administered questionnaire, maternal health manual and perinatal health care information system. Multivariate logistic regression models were conducted to estimate the effects of maternal pre-pregnancy BMI, WC and GWG on obesity-related adverse pregnancy outcomes including gestational diabetes mellitus (GDM), primary cesarean section (P-CS), large for gestational age (LGA) and composite outcome (one or more adverse pregnancy outcomes).

RESULTS

After controlling for all confounders, both maternal pre-pregnancy overweight/obesity and central adiposity contributed to increased risks of GDM [ORs 95% CIs = 2.19 (1.02-4.76) and 2.26 (1.11-4.60), respectively], P-CS [ORs 95% CIs = 1.66 (1.05-2.65) and 1.71 (1.11-2.63), respectively], LGA [ORs 95% CIs = 1.93 (1.07-3.50) and 2.14 (1.21-3.75), respectively] and composite outcome [ORs 95% CIs = 1.82 (1.15-2.87) and 1.98 (1.30-3.01), respectively] compared with mothers with normal pre-pregnancy weight and normal WC. Excessive GWG was found to be associated with an increased risk of LGA [OR 95% CI = 1.74 (1.05-2.89)], but was not significantly related to higher risks of GDM, P-CS and composite outcome [ORs 95% CIs = 0.90 (0.47-1.72), 1.08 (0.77-1.52), and 1.30 (0.94-1.79), respectively]. In terms of the joint effect of maternal pregestational BMI and WC on obesity-related composite outcome, mothers with both pre-pregnancy overweight and central adiposity had the highest risk of composite outcome [OR 95% CI = 3.96 (2.40-6.54)], compared with mothers without pre-pregnancy overweight or central adiposity.

CONCLUSIONS

The results of this study suggest that maternal pre-pregnancy overweight/obesity and central adiposity may contribute to multiple obesity-related adverse pregnancy outcomes, excessive weight gain during pregnancy is associated with an increased risk of LGA. Healthcare providers should carry out health education, and guide women to keep an ideal BMI and WC prior to pregnancy and help them gain optimal weight during pregnancy based on their pre-pregnancy BMI and WC.