Evaluation of the measurement of the fetal fat layer, interventricular septum and abdominal circumference percentile in the prediction of macrosomia in pregnancies affected by gestational diabetes

Diagnostic Accuracy of Fetal Anterior Abdominal Wall Thickness as an Early Sonographic Sign for Diagnosing Gestational Diabetes

Introduction  Traditionally, different fetal variable measurements are used in ultrasound to assess fetal growth. Ultrasound can detect abnormal fetal growth. Gestational diabetes mellitus (GDM) is linked to higher fetal obesity as early as 20 weeks of pregnancy. The amount of fetal adipose tissue may be measured by measuring the thickness of the anterior abdominal wall. Measuring the thickness of the fetus's anterior abdominal wall (AAWT) is a straightforward procedure that may be performed alongside standard abdominal circumference measurements. Objectives  To check the diagnostic accuracy of fetal AAWT as an early sonographic sign for diagnosing GDM, keeping oral glucose tolerance test as the gold standard. Study design  This research was conducted using a cross-sectional analysis. Study place and duration The study was conducted in the Radiology Department at Rawalpindi Medical University and Allied Hospitals from July 10, 2019 to January 9, 2020. Materials and methods  Women between the ages of 18 and 45 who had a family history of type 2 diabetes and were at risk for developing GDM were recruited. Exclusions were made for diabetic women, those carrying multiples, and those with autoimmune diseases. The AAWT measurement of the fetus, which included the skin and subcutaneous tissue, was acquired using the traditional anterior cranial view, 2-3 cm lateral to cord insertion. Pregnant patients at risk for GDM underwent screening using an oral glucose tolerance test. Those exhibiting any two abnormal values were diagnosed with GDM. Results  The overall sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of fetal AAWT as an early sonographic sign for diagnosing GDM, with the oral glucose tolerance test as the gold standard, were 93.14%, 82.65%, 84.82%, 92.05%, and 88.0%, respectively. Conclusion  The study concludes that the diagnostic accuracy of fetal AAWT as an early sonographic indicator for identifying gestational diabetes is notably high.

Mid-Trimester Fetal Anterior Abdominal Wall Subcutaneous Tissue Thickness: An Early Ultrasonographic Predictor of Gestational Diabetes Mellitus

Background This study aimed to determine whether mid-trimester fetal anterior abdominal wall subcutaneous tissue thickness (FASTT) is an early sonographic predictor of gestational diabetes mellitus (GDM), as well as to study its correlation with maternal glycemic values on GDM screening at 24-28 weeks. Methodology We conducted a prospective, case-control study. FASTT was assessed at anomaly scan in 896 uncomplicated singleton pregnancies. The 75-gram oral glucose tolerance test (OGTT) was done for all included patients at 24-28 weeks. Women diagnosed with GDM were taken as cases and appropriately matched in equal numbers as controls. Statistical analysis was done using SPSS version 20 (IBM Corp., Armonk, NY, USA). Independent-samples t-test, chi-square test, receiver operating characteristic curve, and Pearson's correlation coefficient (r) were performed wherever applicable. Results A total of 93 cases and 94 controls were included. Fetuses of women with GDM had significantly higher mean FASTT at 20 weeks (1.605 ± 0.328 mm vs. 1.222 ± 0.121 mm; p < 0.001). The FASTT cut-off obtained was 1.35 mm (sensitivity = 79.6%, specificity = 87.2%, positive predictive value = 86%, negative predictive value = 81.2%). There was a moderate positive correlation between fasting blood sugar (FBS) and two-hour OGTT values and FASTT (r = 0.332, p < 0.001 and r = 0.399, p < 0.001, respectively). FASTT >1.35 mm had an independent predictive value for GDM and was associated with a 19.608-fold increased risk of GDM. Conclusions FASTT values greater than 1.35 mm at 20 weeks are associated with a significantly increased risk of GDM. In addition, FASTT correlates with FBS and two-hour OGTT at 24-28 weeks and is a simple predictor of GDM at 18-20 weeks.

Correlation of Fetal Anterior Abdominal Wall Thickness and Other Standard Biometric Ultrasound Measurements to Predict Fetal Macrosomia in Gestational Diabetes

Background

Gestational diabetes mellitus (GDM) is one of the most common medical conditions affecting pregnancy and significantly increasing the risk for maternal and perinatal complications. The aim of the present study is to study the correlation of fetal anterior abdominal wall thickness (FAAWT) and other standard fetal biometric parameters measured by ultrasound between 36 and 39 weeks of gestation with neonatal birth weight in pregnancies complicated by GDM.

Methods

Prospective cohort study in a tertiary care center including 100 singleton pregnancies with GDM were subjected to ultrasound between 36 and 39 weeks of gestation. Standard fetal biometry (Biparietal diameter, Head Circumference, Abdominal circumference [AC], and Femur Length) and estimated fetal weight were calculated. FAAWT was measured at AC section and actual neonatal birth weights were recorded after delivery. Macrosomia was defined as an absolute birth weight more than 4000 g regardless of the gestational age. Statistical analysis was done and 95% confidence level was considered significant.

Results

Among 100 neonates, 16 were macrosomic (16%) and third trimester mean FAAWT was significantly higher in macrosomic babies (6.36 ± 0.5 mm) as compared to nonmacrosomic babies (5.54 ± 0.61 mm) (P < 0.0001). FAAWT >6 mm (Receiver operating characteristic curve derived) provided a sensitivity of 87.5%, specificity of 75%, positive predictive value of 40%, and negative predictive value (NPV) of 96.9% for prediction of macrosomia. While other standard fetal biometric parameters did not correlate well with actual birth weight in macrosomic neonates, only FAAWT was found to have statistically significant correlation (correlation coefficient of 0.626, P = 0.009).

Conclusion

The FAAWT was the only sonographic parameter to have a significant correlation with neonatal birth weight in macrosomic neonates of GDM mothers. We found a high sensitivity (87.5%), specificity (75%), and NPV (96.9%) suggesting that FAAWT < 6 mm can rule out macrosomia in pregnancies with GDM.

Fetal anterior abdominal wall thickness between gestational diabetes and normal pregnant women

OBJECTIVES

To compare fetal anterior abdominal wall thickness (AAWT) between women with and without GDM during third trimester and to determine accuracy of AAWT to predict large for gestational age (LGA) infants.

MATERIALS AND METHODS

A total of 250 pregnant women, including 125 women with GDM and 125 women without GDM, were enrolled. Tansabdominal ultrasonographic examinations were performed at 28-30, 32-34 and 36-38 weeks. In addition to standard fetal biometries, AAWT was measured. Patient characteristics and ultrasonographic measurements were compared between groups. Sensitivity and specificity of AAWT for identifying LGA were evaluated.

RESULTS

While standard fetal biometries were comparable, mean fetal AAWT in GDM women were significantly higher than those without GDM at 28-30 weeks (2.8 ± 0.8 vs. 2.6 ± 0.6, p = 0.006) and 32-34 weeks (4.0 ± 0.9 vs. 3.5 ± 0.8, p = 0.042). LGA infants had significantly higher fetal AAWT at each time point only in GDM women. Using cut off values of AAWT of ≥2.0, 3.0, and 4.0 mm at 28-30, 32-34, and 36-38 weeks, sensitivity for LGA diagnosis in GDM women were 94.4%, 93.9%, and 89.3%, respectively. The use of abdominal circumference (AC) at >90th percentile showed lower sensitivity but higher specificity, regardless of GDM status. Combination of both measurements increased sensitivity to approximately 90% or higher in every time point, especially among GDM women.

CONCLUSION

Significant increase in fetal AAWT was observed in GDM women at 28-30 and 32-34 weeks. Fetal AAWT significantly increased among LGA infants and had higher sensitivity than AC in identifying LGA during third trimester. In GDM women at 28-30 weeks, AAWT ≥2.0 mm and AC >90th percentile had 97.2% sensitivity for LGA diagnosis.

Ultrasound evaluation of the fetal fat tissue, heart, liver and umbilical cord measurements in pregnancies complicated by gestational and type 1 diabetes mellitus: potential application in the fetal birth-weight estimation and prediction of the fetal macrosomia

BACKGROUND

The aim of the study was to evaluate the ultrasound-derived measurements of the fetal soft-tissue, heart, liver and umbilical cord in pregnancies complicated by gestational (GDM) and type 1 diabetes mellitus (T1DM), and further to assess their applicability in the estimation of the fetal birth-weight and prediction of fetal macrosomia.

METHODS

Measurements were obtained from diet-controlled GDM (GDMG1) (n = 40), insulin-controlled GDM (GDMG2) (n = 40), T1DM (n = 24) and healthy control (n = 40) patients. The following parameters were selected for analysis: fetal sub-scapular fat mass (SSFM), abdominal fat mass (AFM), mid-thigh fat/lean mass (MTFM/MTLM) and inter-ventricular septum (IVS) thicknesses, heart and thorax circumference and area (HeC/HeA; ThC/ThA), liver length (LL), umbilical cord/vein/arteries circumference and area (UmC/UmA; UvC/UvA; UaC/UaA) together with total umbilical vessels (UveA) and Wharton's jelly area (WjA). Regression models were created in order to assess the contribution of selected parameters to fetal birth-weight (FBW) and risk of fetal macrosomia.

RESULTS

Measurements of the fetal SSFM, AFM, MTFM, MTFM/MTLM ratio, HeC, HeA, IVS, LL, UmC, UmA, UaC, UaA, UveA and WjA were significantly increased among patients with GDMG2/T1DM as compared to GDMG1 and/or control groups (p < .05). The regression analysis revealed that maternal height as well as fetal biparietal diameter, abdominal circumference (AC), AFM and LL measurements were independent predictors of the FBW (p < .05). In addition, increase in the fetal AFM, AC and femur length (FL) was associated with a significant risk of fetal macrosomia occurrence (p < .05). The equation developed for the FBW estimation [FBW(g) = - 2254,942 + 17,204 * FL (mm) + 105,531 * AC (cm) + 131,347 * AFM (mm)] provided significantly lower mean absolute percent error than standard formula in the sub-group of women with T1DM (5.7% vs 9.4%, p < .05). Moreover, new equation including AC, FL and AFM parameters yielded sensitivity of 93.8%, specificity 77.7%, positive predictive value 54.5% and negative predictive value of 97.8% in the prediction of fetal macrosomia.

CONCLUSIONS

Ultrasound measurements of the fetal soft tissue, heart, liver and umbilical cord are significantly increased among women with GDM treated with insulin and T1DM. In addition to standard biometric measurements, parameters, such as AFM, may find application in the management of diabetes-complicated pregnancies.

The Relevance of Fetal Abdominal Subcutaneous Tissue Recording in Predicting Perinatal Outcome of GDM Pregnancies: A Retrospective Study

Guidelines on the management of gestational diabetes (GDM) instruct physicians to involve ultrasound-based monitoring of fetal growth in addition to blood glucose. So far, glucose control besides clinical parameters like maternal body mass index (BMI) and gestational weight gain have been shown to predict neonatal outcome. We aimed to evaluate the discriminative ability of fetal abdominal subcutaneous tissue (FAST) in addition to standard ultrasound parameters like abdominal circumference (AC) and estimated fetal weight (EFW) for perinatal complications like large for gestational age (LGA), hypoglycemia, hyperbilirubinemia, mode of delivery and admission to neonatal intensive care unit (NICU). Ultrasound data and neonatal outcome was collected of 805 GDM cases from 2012 to 2016: 3205 FAST, 3195 AC-measurements and 3190 EFW calculations were included. AC, EFW and FAST increased linear with gestational age. Combining ultrasound and clinical parameters improved predictive power for LGA. In the subgroup where fetuses grow with an AC > 75th additional adding of FAST to standard ultrasound parameters increased predictive power for hypoglycemia. Our results confirm inclusion of ultrasound parameters to be beneficial in monitoring GDM pregnancies. Additional FAST determination revealed to be of potential clinical relevance in the subgroup AC > 75th percentile.

Fetal Epicardial Fat Thickness: Can It Serve as a Sonographic Screening Marker for Gestational Diabetes Mellitus?

Background

Gestational diabetes mellitus (GDM) is defined as the new onset of impairment in carbohydrate tolerance during pregnancy. The aim of the current study was to define fetal epicardial fat thickness (fEFT) changes that developed before 24 weeks of gestation, to evaluate the diagnostic effectiveness of fEFT in predicting GDM diagnosis, and to correlate fEFT values with hemoglobin A1C (HbA1C) values.

Methods

The study included a total of 60 GDM patients and 60 control subjects. A record consisted of fEFT measurements, maternal body mass index, maternal subcutaneous fat thickness, and fetal subcutaneous fat thickness during sonographic screening performed at 18-22 gestational weeks. Fetal abdominal circumference (AC) values, estimated fetal weight (EFW), and fetal gender were also recorded.

Results

The median fEFT measurement of the whole study population was 0.9 ± 0.21 mm; 1.05 ± 0.21 mm in the GDM patients, and 0.8 ± 0.15 mm in the control group. The median fEFT values of the GDM patients were significantly higher than those of the control group (P < 0.01). According to the correlation analysis results, a strong positive correlation was determined between the fEFT and HbA1C values (r = 0.71, P < 0.01), gestational week of the fetus (r = 0.76, P = P < 0.01), AC (r = 0.81, P < 0.01), and EFW (r = 0.71, P < 0.01). According to the receiver operating characteristic analysis results, a fEFT value of > 0.95 can predict GDM diagnosis with sensitivity of 65% and specificity of 88% (odds ratio = 13).

Conclusion

fEFT values are increased in GDM cases, and the increase can be detected earlier than 24 weeks of gestation. fEFT values are positively correlated with HbA1C values and can serve as an early predictor for GDM diagnosis.

Pregestational diabetes in pregnancy: Complications, management, surveillance, and mechanisms of disease-A review

Diabetes is an increasingly common diagnosis among pregnant women. Pregestational diabetes is associated with an increase in many adverse pregnancy outcomes, which impact both on the woman and her fetus. The models of pregnancy care for women with diabetes are based largely on observational data or consensus opinion. Strategies for aneuploidy screening and monitoring for fetal well-being should be modified in women with diabetes. There is an increasing understanding of the mechanisms by which congenital anomalies and disorders of fetal growth occur, involving epigenetic modifications, changes in gene expression in critical developmental pathways, and oxidative stress. This knowledge may lead to pathways for improved care for these high-risk pregnancies.

Fetal front-abdominal wall thickness in the second trimester as a predictor of abnormal fetal growth

Objectives: Worldwide, approximately 9% of infants have a birth weight ≥4000 g, who are defined as fetal macrosomia, with wide variations between countries. Another form of abnormal fetal growth is fetal growth restriction. Infants with low birth weight (LBW) for their gestational age are primarily categorized as either small for gestational age (SGA) or fetal (intrauterine) growth restriction (FGR). All forms of abnormal fetal growth have high morbidity rates of neonatal. Therefore, diagnosis of abnormal fetal growth as early as possible is crucial for optimal clinical care. The measurement of fetal front-abdominal wall thickness (FAWT) is an easy examination. We conducted this study, wondering whether FAWT can predict birth weight or can determine LGA/macrosomia and/or LBW infants in advance.Methods: This longitudinal cohort study was done in a tertiary center between September 2016 and September 2019. In total, 768 pregnant women with who attended our clinic for oral glucose tolerance test (OGTT) screening between the 26th and 28th weeks of gestation were included in this study. A total of 768 patients were evaluated in the present study. However, 186 of them were excluded in the follow-up of the study because they met the exclusion criteria or they gave birth in another hospital. Eventually, 582 pregnant women were included, with 57 in the LBW group, 461 in the AGA group, and 64 in the LGA group. In addition, 55 fetuses in the LGA group were determined to be macrosomic (birth weight > 4000 g). The FAWT and classic fetal biometric measurements, such as BPD, AC, FL, and EFW, were compared between the AGA group and the macrosomic infants. Statistical analysis was performed to compare the AGA group and the macrosomic infants group. There were no macrosomic infants in the AGA group, so this was used as the control group.Results: There were no significant differences between the groups for maternal age, gravidity, parity, gestational age on the day of the examination, and gestational age at birth. The mean FAWT was significantly thinner in the SGA group than in the appropriate for gestational age (AGA) group (3.4 versus 3.9 mm, respectively, p < .001), while it was significantly thicker in the LGA group than in the AGA group (4.1 versus 3.9 mm, respectively, p < .001).Conclusion: FAWT measurement can provide more information and may be more sensitive toward fetal nutrition and growth than the AC value during the second trimester. Some benefits can be gained through the measurement of FAWT at the end of the second trimester. FAWT measurements can be used in obstetrical practice with a similar performance in predicting the LGA and macrosomic infant like AC and EFW.

Reference range of fetal myocardial area by three-dimensional ultrasonography and its applicability in fetuses of pre-gestational diabetic women

Objective To determine the reference range for the myocardial area in healthy fetuses using three-dimensional (3D) ultrasonography and validate these results in fetuses of pregnant women with pre-gestational diabetes mellitus (DM). Methods This cross-sectional retrospective study included 168 healthy pregnant women between gestational weeks 20 and 33+6 days. The myocardial area was measured using spatio-temporal image correlation (STIC) in the four-chamber view. Polynomial regression models were used, and the goodness of fit of the models were evaluated by the coefficient of determination (R2). Intra- and inter-observer reproducibility was determined using the concordance correlation coefficient (CCC). Validation was performed in 30 pregnant women with pre-gestational DM. Results There was a strong correlation (R2=0.71, P<0.0001) between myocardial area and gestational age. There was good intra- and inter-observer reproducibility, with a CCC of 0.86 and 0.83, respectively. However, there was no significant difference in the mean myocardial area between healthy fetuses and fetuses of women with pre-gestational DM (0.11 cm2, P=0.55). Conclusion The reference range was determined for the myocardial area in fetuses, and there was no significant difference in this variable between healthy fetuses and the fetuses of women with pre-gestational DM.

The effect of maternal obesity on fetal biometry, body composition, and growth velocity

Introduction: The aim of this secondary analysis was to investigate the relationship between maternal body mass index (BMI) and fetal biometry, body composition, and velocity measurements at 28 and 36 weeks gestation.Materials and methods: The current analysis involves 911 overweight or obese women who were randomized to the Standard Care group of the LIMIT randomized trial.Results: The fetus of women with Class 3 obesity (BMI ≥ 40.0) showed the greatest increase in all biometry z-scores, abdominal area (AA), and abdominal fat mass (AFM) compared with women classified as overweight (BMI 25.0-29.9). In women with Class 3 obesity, AA velocity was increased by 0.035 cm² (0.004, 0.066, p = .029) and the z-score velocity was increased by 0.238 (0.022, 0.453, p = .03). Estimated fetal weight (EFW) velocity for women with Class 3 obesity was higher than that of overweight women by 2.028 g per day (0.861, 3.196, p<.001) and the z-score velocity was also higher by 0.441 per day (0.196, 0.687, p < .001).Conclusions: Maternal obesity is associated with an increase in fetal abdominal circumference, AFM and area along with EFW velocity over time. Women with Class 3 obesity (BMI ≥ 40.0) may represent a higher risk group for perpetuating the intergenerational transmission of obesity to their offspring.

Measurement and evaluation of fetal fat layer in the prediction of fetal macrosomia in pregnancies complicated by gestational diabetes

OBJECTIVES

To explore the predictive power of measuring the abdominal fetal fat layer (FFL) as a soft tissue marker at 31, 34, and 37 weeks' gestation to improve the detection of fetal macrosomia in pregnant women with GDM, in addition to the biometric values with close monitoring of maternal blood sugar level and BMI changes.

METHODS

We conducted a prospective observational study at the Department of Obstetrics, University Hospitals, Campus Kiel, Germany, in collaboration with diabetic clinic staff. Participants underwent a third-trimester scan and extra FFL measurements were performed at 31, 34, and 37 weeks of gestation. The clinical outcomes of pregnancy and birth weight were collected from the obstetric record. All of the enrolled women had an early pregnancy ultrasound scan to confirm gestational age.

RESULTS

The FFL at 34 and 37 weeks, with respective cutoff values of >0.48 cm and >0.59 cm, showed a very good sensitivity of 60% for both gestational points, and specificity of 89.3 and 90.6%, respectively. The probability of fetal macrosomia could be more than doubled if the FFL at 34 weeks was more than 0.48 cm. However, the probability of macrosomia dropped to 16% if the FFL was ≤0.48 cm. The median FFLs of macrosomic fetuses at 34 and 37 weeks were 0.50 (IQR 0.10) and 0.60 (IQR 0.25) cm, respectively. The mean age of the study population (n = 80) was 32.26 (SD = 5.06) years. In our study population, ten newborns were born with birth weight >4000 g. The body mass index (BMI) for the mothers of later-onset macrosomic newborns showed higher median values of 30 (IQR 8), 32 (IQR 5), and 33 (IQR 9) at 31, 34, and 37 weeks, respectively, in comparison to mothers of non-macrosomic newborn. However, the BMI did not show any statistically significant difference from those with normal-weight newborn and did not show any specific sensitivity for predicting macrosomia.

CONCLUSION

Measuring the FFL at 34 and 37 weeks of gestation, in addition to the standard measurement, might be useful for predicting macrosomia and is worth further evaluation.

Are There Benefits for Gestational Diabetes Mellitus in Treating Lower Levels of Hyperglycemia Than Standard Recommendations?

OBJECTIVES

The new International Association of Diabetes and Pregnancy Study Groups (IADPSG) recommendations for diagnosis of gestational diabetes mellitus (GDM) are generating discussion regarding their universal adoption. Our centre is currently using stricter GDM diagnostic criteria than those proposed by the IADPSG. Evaluation of complication rates and their predictors in our cohort may provide insight for the care of this high-risk population. Therefore, we determined complication rates and identified antepartum maternal predictors of adverse outcomes in our cohort with mild GDM.

METHODS

A retrospective cohort study was performed between 2005 and 2011. It included women with and without GDM, which was diagnosed if fasting plasma glucose levels were 5.0 or above or 2-hour post 75 gram oral glucose tolerance test (OGTT) were 7.8 mmol/L or higher.

RESULTS

A total of 3712 women, with and without diabetes, were included. Rates of macrosomia and pre-eclampsia were significantly higher in the group with GDM but were lower than the rates usually reported. Macrosomia, the need for insulin therapy or caesarean section and postpartum glucose intolerance predictors included prepregnancy body mass index, excessive gestational weight gain and OGTT screening results, although no specific threshold was found.

CONCLUSIONS

This study provides insight into GDM-related complications rates and the benefits of intervention in a large cohort of women with levels of hyperglycemia lower than those currently recommended for diagnosis of GDM. These findings suggest a continuous association between adverse outcomes and maternal hyperglycemia and highlight the important role of maternal risk factors other than glycemic results in the development of pregnancy-related complications. Milder forms of hyperglycemia that would not be identified by IADPSG guidelines may benefit from treatment.

Antenatal dietary and lifestyle advice for women who are overweight or obese and the effect on fetal growth and adiposity: the LIMIT randomised trial

OBJECTIVE

To report the influence of maternal overweight and obesity on fetal growth and adiposity and effects of an antenatal dietary and lifestyle intervention among these women on measures of fetal growth and adiposity as secondary outcomes of the LIMIT Trial.

DESIGN

Randomised controlled trial.

SETTING

Public maternity hospitals in metropolitan Adelaide, South Australia.

POPULATION

Pregnant women with a body mass index ≥ 25 kg/m(2), and singleton gestation between 10(+0) and 20(+0) weeks.

METHODS

Women were randomised to Lifestyle Advice or continued Standard Care and offered two research ultrasound scans at 28 and 36 weeks of gestation.

MAIN OUTCOME MEASURES

Ultrasound measures of fetal growth and adiposity.

RESULTS

For each fetal body composition parameter, mean Z-scores were substantially higher when compared with population standards. Fetuses of women receiving Lifestyle Advice demonstrated significantly greater mean mid-thigh fat mass, when compared with fetuses of women receiving Standard Care (adjusted difference in means 0.17; 95% CI 0.02-0.32; P = 0.0245). While subscapular fat mass increased between 28 and 36 weeks of gestation in fetuses in both treatment groups, the rate of adipose tissue deposition slowed among fetuses of women receiving Lifestyle Advice, when compared with fetuses of women receiving Standard Care (P = 0.0160). No other significant differences were observed.

CONCLUSIONS

These findings provide the first evidence of changes to fetal growth following an antenatal dietary and lifestyle intervention among women who are overweight or obese.

Fetal epicardial fat thickness in diabetic and non-diabetic pregnancies: A retrospective cross-sectional study

OBJECTIVE

To evaluate fetal epicardial fat thickness (EFT) in diabetic and control pregnancies.

METHODS

A retrospective cross-sectional study was performed in which fetal EFT was measured in the second trimester in 28 diabetics and 28 non-diabetic patients. Maternal BMI, estimated fetal weight, birth weight, fetal abdominal circumference, and subcutaneous fat thickness were also collected. Statistical analysis was carried out by means of chi-square, Wilcoxon rank-sum test, Student's T test, and linear regression as appropriate.

RESULTS

EFT was significantly higher in diabetic (1.43 mm) vs. control fetuses (1.16 mm), P = 0.02. This relationship remained significant when controlling for covariates.

CONCLUSIONS

EFT was higher in fetuses of diabetic mothers vs. fetuses from controls. If confirmed in prospective studies, this may represent a novel marker for altered fetal metabolism due to maternal diabetes.

Role of ultrasound in the management of diabetes in pregnancy

The purpose of this review is to discuss the established role of ultrasound (US) in the management of pregnancy complicated by diabetes mellitus (DM), as well as new developments with regard to the use of US in this situation. We choose to explore the role of US in pregnancy complicated by DM in three areas: (1) Role of US in estimation of fetal weight. (2) Role of US in diagnosis of congenital malformation. (3) Role of US in monitoring diabetic pregnant patients.

Fetal myocardial wall area: constructing a reference range by means of spatiotemporal image correlation in the rendering mode

OBJECTIVE

To establish the reference range of the myocardial wall area in the fetus using three-dimensional ultrasound in the rendering mode.

METHODS

A prospective, cross-sectional study including 371 singleton, uncomplicated pregnancies at 20 weeks 0 day to 33 weeks 6 days of gestation was carried out. Cardiac volumes were obtained using spatiotemporal image correlation (STIC) at the level of the four-chamber view. The end-diastolic myocardial area of the both ventricles was measured manually. The intraclass correlation coefficient (ICC) was used to assess intra- and interobserver concordance.

RESULTS

The mean myocardial area of the fetal right ventricular (RV) wall ranged from 0.86 ± 0.23 cm(2) at 20 weeks 0 day to 2.75 ± 0.69 cm(2) at 33 weeks 6 days of gestation. The mean myocardial area of the fetal left ventricular (LV) wall ranged from 0.82 ± 0.20 cm(2) at 20 weeks 0 day to 2.49 ± 0.59 cm(2) at 33 weeks 6 days of gestation. In addition, intra- and interobserver concordance for the myocardial area of the RV and LV walls was good, with ICC values of 0.94, 0.95, 0.85, and 0.93, respectively.

CONCLUSIONS

The reference range for the myocardial area of the RV and LV walls was determined by cardio-STIC in the rendering mode at 20 weeks 0 day to 33 weeks 6 days of gestation, with good concordance between values.

Correlation of fetal abdominal subcutaneous tissue thickness by ultrasound to predict birth weight

INTRODUCTION

Fetal growth abnormality is associated with changes in the soft tissue mass, which is decreased in growth restricted fetuses and increased in macrosomia.

OBJECTIVE

To correlate fetal abdominal subcutaneous tissue thickness (FASTT) measured by ultrasound at term and birth weight and to obtain a cut-off value of FASTT to predict large and small for gestational age babies in our population.

METHODS

FASTT was measured at the anterior 1/3(rd) of abdominal circumference by ultrasound after 36 weeks and weight of the baby measured after birth.

RESULTS

There was positive correlation between FASTT and birth weight. FASTT of 6.25 mm was sensitive to predict large for gestational age (LGA) babies and had a high negative predictive value; FASTT measurement for prediction of small babies with birth weight < 2500 g was not sensitive.

CONCLUSION

FASTT can be used as an additional indicator to predict large for gestational age babies along with other known birth weight indicators.

Reference range for fetal interventricular septum area by means of four-dimensional ultrasonography using spatiotemporal image correlation

OBJECTIVE

To determine reference range for fetal interventricular septum area by means of 3-dimensional ultrasonography (3DUS) using the spatiotemporal image correlation (STIC) method.

METHODS

A prospective, cross-sectional study was conducted on 328 normal pregnant women between the 18th and 33rd gestational weeks. To obtain the interventricular septum area, a virtual plane was used, with the green line (region of interest) adjacent to the external margin of the septum, which was manually delimited. To evaluate the correlation of the septum area with the gestational age, different regression modes were evaluated. The intraclass correlation coefficient was used to evaluate the interobserver reproducibility.

RESULTS

The interventricular septum area showed correlation with the gestational age (r = 0.81). The mean increased from 0.47 ± 0.10 cm² in the 18th week to 2.42 ± 1.13 cm² in the 33rd week of gestation. The mathematical equation that best represented this correlation was provided by linear regression: interventricular septum area = 0.0511 × gestational age (R² = 0.095). The interobserver reproducibility was good, with bias of 0.01 cm², precision of 0.07 cm² and absolute limits of agreement of -0.14 and +0.15 cm².

CONCLUSIONS

Reference range for fetal interventricular septum area were determined by means of 3DUS using STIC in the rendering mode and were shown to be reproducible.

The effects of adjuvant insulin therapy among pregnant women with IGT who failed to achieve the desired glycemia levels by diet and moderate physical activity

OBJECTIVE

Evaluation of adjuvant insulin therapy effects on glycemic control, perinatal outcome and postpuerperal glucose tolerance in impaired glucose tolerance (IGT) pregnant women who failed to achieve desired glycemic control by dietary regime.

METHODS

A total of 280 participants were classified in two groups: Group A patients continued with dietary regime and Group B patients were treated with adjuvant insulin therapy. Glycemic control was assessed by laboratory and ultrasonograph means. Pregnancy outcomes were evaluated by prevalence of pregnancy induced hypertension (PIH), high birth weight, neonatal hypoglycemia and caesarean section rates. Postpuerperal glucose tolerance was assessed by oral glucose tolerance test (oGTT).

RESULTS

All laboratory and ultrasound indicators of glycemic control had significantly lower values in Group B. Group A women were more likely to develop the EPH (Edema, Proteinuria, Hypertension) syndrome, 20% versus 7.86% (p = 0.003). High birth weight occurred more frequently in Group A, but the difference was not significant (p = 0.197). Higher rate of caesarean delivery was in Group A than in Group B, 16.43% versus 26.43% (p = 0.041). The difference in neonatal hypoglycemia was not significant (p = 0.478). Pathological oGTT results were observed in 73 Group A patients and in 15 Group B patients.

CONCLUSION

Lower caesarean section rates and the EPH syndrome incidence are the benefits of adjuvant insulin therapy in IGT patients.

Sensitivity and specificity of ultrasonography as a screening tool for gestational diabetes mellitus

OBJECTIVE

To evaluate diagnostic accuracy and efficiency of ultrasound markers of gestational diabetes (GDM) and propose an ultrasound based scoring system suitable for screening (UGDS).

METHODS

110 women with singleton pregnancies and established maternal and/or pregnancy related risk factors for GDM were scanned at/or after 24 weeks gestation followed by administration of a 3 hour 100-gram oral glucose tolerance test (oGTT). A number of ultrasound markers were determined/measured, including fetal adipose subcutaneous tissue, asymmetrical macrosomy, cardiac circumference, cardiac width, and interventricular septum thickness, immature appearance of placenta, intensified breathing movements, polyhydramnios and placental thickness. Each ultrasound GDM marker was assigned one point to create the ultrasound gestational diabetes screening score (UGDS).

RESULTS

All ultrasound GDM markers were positively correlated to the disease P < 0.0001. The strongest independent predictor of GDM was an immature appearance of placenta (RR 40.1 95% CI 5.9-271.0, P < 0.0001). Receiver operator characteristics (ROC) showed an area under the curve of 95.7% confirming good ability of UGDS to discriminate between positive and negative oGTT. We propose a UGDS score of 4 providing sensitivity of 90.9%, and specificity 89.6%.

CONCLUSIONS

This study suggests that UGDS is a good predictor of GDM.

The role of umbilical cord thickness and HbA1c levels for the prediction of fetal macrosomia in patients with gestational diabetes mellitus

OBJECTIVE

The aim of this study was to investigate the effects of HbA1c levels and umbilical cord thickness upon birth weight, particularly in pregestational and gestational diabetic patients.

METHOD

Pregnant women were included in the study and were divided into two groups. The first group consisted of patients who were diagnosed with pregestational or gestational diabetes mellitus. The control group consisted of pregnant women who were not diagnosed with pregestational or gestational diabetes mellitus. Ultrasound examination was performed twice. Examinations were performed at 27-28 weeks and 36-37 weeks of gestation, respectively. During ultrasound examinations, fetal anthropometric parameters, biparietal diameter, abdominal circumference, femur length and estimated fetal weight (which was calculated automatically according to Hadlock's formula) were measured. Additionally, the sonographic cross-sectional areas of the umbilical cord, the umbilical arteries and the umbilical vein were measured in a free loop of the umbilical cord, using the software of the ultrasound machine. The cross-sectional area of Wharton's jelly was computed by subtracting the cross-sectional area of the vessels from that of the umbilical cord. HbA1c levels were measured for diabetic patients.

RESULTS

At 27-28 gestational weeks, umbilical cord area and Wharton's jelly values were found to be statistically different in macrosomic fetuses compared with non-macrosomic fetuses for both groups (for cord area, P = 0.012; for Wharton's jelly, P = 0.001). Additionally, umbilical cord diameter vein and artery values were not statistically different between the two groups when macrosomic fetuses were compared with non-macrosomic fetuses. At 36-37 gestational weeks, when the relationship between umbilical cord components and birth weight was examined, there was a statistically significant difference when comparing macrosomic fetuses with non-macrosomic fetuses. There was a statistically significant correlation between umbilical cord area, umbilical cord diameter and fetal weight estimation at 36-37 gestational weeks. HbA1c values and fetal macrosomia did not show a statistically significant relationship (P = 0.701).

CONCLUSION

A significant relationship between umbilical cord components and birth weight was not specific for the diabetic group. There was a significant relationship between birth weight and umbilical cord components for the control group as well. If the estimated fetal weight is combined with umbilical cord components, macrosomic fetuses can be predicted with more accuracy.

Non-diabetic macrosomia: an obstetric dilemma

Fetal macrosomia represents a continuing challenge in obstetrics, as it has risk of shoulder dystocia leading to transient or permanent fetal, maternal injury and medicolegal liability. The overall incidence of macrosomia has been rising. Non-diabetic macrosomia is still an obstetric dilemma, as there is no clear consensus regarding its ante-partum prediction and management, as accurate diagnosis is only made retrospectively. The risk of shoulder dystocia rises from 1.4% for all vaginal deliveries to 9.2-24% for birth weights more than 4,500 g. Unfortunately, 50% of all cases of shoulder dystocia occur at birth weights of less than 4,000 g. Brachial plexus injury occurs in 1:1,000 births and permanent damage in 1:10,000 deliveries (12% of all) leading to litigation 1:45,000 deliveries. The prenatal diagnosis of macrosomia remains imprecise. Pre-pregnancy and ante-partum risk factors and ultrasound have poor predictive value. Induction of labour and prophylactic caesarean delivery has not been shown to alter the incidence of shoulder dystocia among nondiabetic patients. Caesarean section and induction of labour are associated with increased risk of operative morbidity and mortality with added cost implications.

Reproducibility of sonographic assessment of fetal liver length in diabetic pregnancies

OBJECTIVES

Assessing fetal liver size might be useful in monitoring the effectiveness of the treatment of diabetes in pregnancy. We aimed to assess the reproducibility of fetal liver-length measurement in pregnant women with diabetes.

METHODS

From 3 April 2006 to 5 December 2006, we assessed intraobserver and interobserver variation of fetal liver-length measurements on 55 sonograms in 44 pregnant women with diabetes, 34 of whom had gestational diabetes. The mean maternal age was 33 years, the mean maternal weight was 92 kg and the mean body mass index (BMI) was 33.7 kg/m(-2). The effect of covariates BMI, gestational age and maternal age on the reproducibility of fetal liver length was assessed by calculating intraobserver SD ratios. We compared liver length with abdominal circumference and gestational age. Nine of 12 sonographers scanned, on average, six women (range, 3-12) as the first sonographer, and all 12 sonographers scanned, on average, four women (range, 1-10) as the second sonographer. The data were analyzed using a hierarchical linear model.

RESULTS

Measurement of fetal liver length was reproducible. The intraobserver SD was 3.06 (95% CI, 2.68-3.59) mm; the interobserver SD was 2.17 (95% CI, 0.59-4.83) mm; the intraobserver correlation was 0.77 (95% CI, 0.63-0.87), and the interobserver correlation was 0.84 (95% CI, 0.51-0.99). The covariate effects were minimal, the SD for a 1-unit increase in the covariate was 1.06 for gestational age, 0.98 for BMI, and 0.97 for maternal age.

CONCLUSIONS

Measurement of fetal liver length in the diabetic pregnancy is reproducible. It is worthy of further investigation as a parameter for monitoring the effectiveness of treatment of the diabetic pregnancy.

Large cross-sectional area of the umbilical cord as a predictor of fetal macrosomia

OBJECTIVE

To determine whether a large cross-sectional area of the umbilical cord is a predictor of fetal macrosomia.

METHODS

Consecutive patients of > 34 weeks' gestation, who presented for sonographic examination and who delivered within 4 weeks of the examination, were included in the study. The sonographic cross-sectional areas of the umbilical cord, the umbilical vessels and the Wharton's jelly were measured in a free loop of the umbilical cord. Logistic regression analysis was used to determine significant predictors of macrosomia (actual birth weight > 4000 g and > 4500 g). Fetal biometric parameters (biparietal diameter, abdominal circumference and femur length), sonographic estimated fetal weight and umbilical cord area > 95(th) centile for gestational age were used as covariates.

RESULTS

During the study period, 1026 patients were enrolled. Fifty-three (5.2%) newborns had a birth weight > 4000 g, and 22 (2.1%) weighed > 4500 g. The proportion of cases with a large umbilical cord was significantly higher in the group of macrosomic compared with non-macrosomic infants (54.7% vs. 8.7%, P < 0.0001). Multiple regression models demonstrated an independent contribution of the large cord in the prediction of birth weight > 4000 g and > 4500 g (odds ratio (95% CI), 20.6 (9.2-45.9) and 4.2 (1.2-17.7), respectively). The sensitivity, specificity and positive and negative predictive values of a sonographic large umbilical cord were 54.7%, 91.3%, 25.4%, and 97.4%, respectively. The combination of abdominal circumference > 95(th) centile and large cord predicted 100% of macrosomic infants. The proportion of umbilical cords with a Wharton's jelly area > 95(th) centile for gestation was significantly higher in macrosomic fetuses of diabetic compared with non-diabetic mothers.

CONCLUSIONS

Sonographic assessment of umbilical cord area may improve the prediction of fetal macrosomia.

Detection and prevention of macrosomia

It is overly simplistic to try to identify optimal glycemic thresholds, fetal growth characteristics, and methods of detection in the prevention of fetal overgrowth and its attendant morbidities that can be applied to all pregnancies. We can only hope that, as our understanding of the pathophysiology of diabetes in pregnancy grows, we can "fine-tune" our therapy and surveillance to meet the needs of an individual woman who has diabetes and her fetus.

Gestational diabetes mellitus: fetal liver length measurements between 21and 24 weeks' gestation

PURPOSE

To evaluate sonographic measurements of the fetal liver, fetal abdominal fat layer, interventricular septum, and Wharton's jelly area between 21 and 24 weeks' gestation in women with gestational diabetes mellitus (GDM).

METHODS

A total of 123 consecutive healthy pregnant women underwent sonographic examination at 21-24 weeks' gestational age. The measurements included fetal biometry, detailed anomaly scan, and fetal body composition measurements (subcutaneous fat, liver size, cardiac muscle thickness, and Wharton's jelly area). GDM was confirmed by way of a 75-g oral glucose tolerance test using World Health Organization criteria within 1 week of the examination.

RESULTS

Nineteen (15.4%) women were diagnosed with GDM, while 104 (84.6%) women were without GDM. The mean fetal liver length was 36 mm (95% CI 32-37) in women with GDM and 31 mm (95% CI 30-33) in women without GDM (p < 0.01). Liver enlargement was related to maternal fasting glucose levels and not 2-hour postprandial levels. There was no significant difference in the fetal biometric and other fetal body measurements between the 2 groups.

CONCLUSIONS

The findings of this study suggest that midtrimester fetal liver length appears to be longer in GDM than in normal pregnancies. However, the fetal abdominal fat layer, interventricular septum, and Wharton's jelly were not affected. Nevertheless, further, larger randomized studies are required to confirm these findings.

Maternal obesity, metabolism, and pregnancy outcomes

About one third of all pregnant women in the United States are obese. Maternal obesity at conception alters gestational metabolic adjustments and affects placental, embryonic, and fetal growth and development. Neural tube defects and other developmental anomalies are more common in infants born to obese women; these defects have been linked to poor glycemic control. Preeclampsia, a gestational disorder occurring more frequently in obese women, appears to be due to a subclinical inflammatory state that impairs early placentation and development of its blood supply. Fetal growth and development during the last half of pregnancy depends on maternal metabolic adjustments dictated by placental hormones and the subsequent oxygen and nutrient supply. Maternal obesity affects these metabolic adjustments as well. Basal metabolic rates are significantly higher in obese women, and maternal fat gain is lower, possibly in response to altered leptin function. The usual increase in insulin resistance seen in late pregnancy is enhanced in obese mothers, causing marked postprandial increases in glucose, lipids, and amino acids and excessive fetal exposure to fuel sources, which in turn increases fetal size, fat stores, and risk for disease postnatally. Impaired glucose tolerance, gestational diabetes, and hyperlipidemia are more common among obese mothers. To date, little attention has been given to the role of diet among obese women in preventing these problems. However, studies of women with impaired glucose tolerance show that replacing refined carbohydrates and saturated fat with complex, low-glycemic carbohydrates and polyunsaturated fatty acids improves metabolic homeostasis and pregnancy outcomes. Thus, current dietary guidelines regarding the amount and type of carbohydrates and fat for nonpregnant women seem appropriate for pregnant women as well.

Can ultrasound fetal biometry predict fetal hyperinsulinaemia at delivery in pregnancy complicated by maternal diabetes?

OBJECTIVE

The aim of this study was to determine whether there is an association between ultrasound fetal biometry and amniotic fluid insulin levels at delivery in women with pre-existing diabetes or impaired glucose tolerance in pregnancy.

STUDY DESIGN

This retrospective cohort study identified 93 women who had amniotic fluid insulin levels measured at time of delivery. Standardised estimated fetal weight and fetal growth velocity were calculated from serial third trimester fetal ultrasound measurements.

RESULTS

Women with pre-existing diabetes had significantly greater mean growth velocity [1.39 (95% CI: 0.43-2.23) versus 0.39 (95% CI: -01.7-0.95); p=0.04], significantly greater mean estimated fetal weight (EFW) Z score prior to delivery [2.36 (95% CI: 1.82-2.9) versus 1.38 (95% CI: 1.02-1.74); p=0.002] and greater mean birthweight centile [82 (95% CI: 0.74-0.89) versus 67 (95% CI: 58-76); p=0.02] than those with GDM/IGT. Amniotic fluid insulin levels demonstrated a similar significant difference between the pre-existing and GDM/IGT groups [20.5 (95% CI: 12.9-28.1) versus 8.5 (95% CI: 5.4-11.7); p=0.001]. An association between fetal growth and size and amniotic fluid insulin was observed in women with pre-existing diabetes. Positive likelihood ratios were 1.67 and 2.08, respectively, for the prediction of liquor insulin greater than the 95th centile in women with pre-existing diabetes.

CONCLUSION

Ultrasound measures of fetal size and growth used in this study are not sufficiently accurate to predict those infants likely to be at risk from the adverse effects of fetal hyperinsulinaemia.

Fetal cheek-to-cheek diameter in the prediction of mode of delivery

OBJECTIVE

The purpose of this study was to assess sonographic fetal cheek-to-cheek diameter (CCD) in predicting mode of delivery.

STUDY DESIGN

Two hundred sixty-four patients were considered in 2 parts. First, a retrospective analysis of 214 patients entered into a birth weight (BW) study. Measurements of the CCD, biparietal diameter (BPD), and BW, as well as labor data, were collected. Then a prospective study of patients at > or =38 weeks gestational age was conducted. Fetal weight (EFW) was estimated by routine measurements. Information regarding CCD was withheld from the delivering caregiver. Labor records were reviewed for BW and complications, defined as: instrumental delivery, cesarean section (C/S) for nonprogress of labor or "CPD," and "difficult" vaginal delivery. The CCD, BW (both parts), or EFW (prospective part) and mode of delivery were compared.

RESULTS

Abnormal CCD (>2SD above previously published norms for each GA) was closely associated with cesarean delivery, regardless of EFW. At term, risk of C/S with a CCD >7.9 cm was 94%.

CONCLUSION

Within limits, EFW alone has weak correlation with cesarean delivery. CCD, as a reflector of fetal adipose tissue, performs as well as actual BW and demonstrates good prediction for delivery by C/S.

Individualized growth assessment of fetal soft tissue using fractional thigh volume

OBJECTIVES

The main goals of this study were to introduce fractional thigh volume (TVol) as a new soft tissue parameter for fetal growth evaluation, define its relationship to menstrual age, and develop individualized fetal growth standards based on Rossavik growth models.

METHODS

A prospective, longitudinal study of 22 fetuses was conducted with conventional biometry and TVol measurements by three-dimensional ultrasonography. Infant growth outcomes were determined from modified neonatal growth assessment scores. Rossavik functions (P = c(t)k+s(t)) were used to fit complete datasets to examine relationships between TVol and model coefficients. Second-trimester models were subsequently specified from the linear slopes of growth curves before 28.0 menstrual weeks with each fetus acting as its own control. Third-trimester trajectories and birth measurements were predicted for standard growth parameters and TVol. Observed and predicted measurements were compared using percent deviations and growth potential realization index values. Four additional infants, with serial prenatal scans and postnatal evidence of intrauterine growth restriction (IUGR), were also evaluated.

RESULTS

All 22 fetuses had no evidence of growth abnormalities after delivery. Accelerated soft tissue deposition occurred in the fetal thigh by 28 menstrual weeks. A mean TVol start point of 9.0 +/- 1.4 menstrual weeks was consistent with embryological studies of thigh development. Rossavik functions fitted all TVol trajectories well (mean R2 = 0.998 +/- 0.002). By fixing the coefficient k at its mean value (2.976), the fit did not change and the variabilities of coefficients c and s were reduced. The mean percent deviation between observed and predicted third-trimester TVol measurements was -0.048 +/- 7.5%. Relatively early pathological deviations were observed for TVol in all four fetuses with IUGR; in these cases the abdominal circumference was abnormal in only one fetus and thigh circumference in none.

CONCLUSIONS

Individualized growth assessment can be used to accurately predict TVol during the third trimester of pregnancy and at birth. Expected growth trajectories, from second-trimester data, do not rely on population-based standards because each fetus serves as its own control. This new parameter may allow earlier detection and improved monitoring of fetal soft tissue abnormalities such as IUGR.