Choice of standards for sonographic fetal abdominal circumference percentile

To evaluate the prognostic values of fetal size before birth and fetal growth during the latency period in patients with preterm premature rupture of the membranes (PROM). A prospective cohort study of 69 singleton pregnancies complicated by prolonged (14 days or more) PROM (24 to 31 weeks of gestation). Measures of fetal size and growth were compared with corresponding expected values from our reference curves. The correlations between deviations from expected measures of fetal size and growth, short-term neonatal complications, and infant neurodevelopmental outcome at 2 years were studied by univariate methods and logistic regression. The mean gestational ages and standard deviations at membrane rupture and at birth were 27.9 +/- 2.4 and 31.5 +/- 2.1 weeks. At a corrected age of 2 years, of the 65 (94.2%) survivors, 3 infants (4.6%) had cerebral palsy, 13 (20%) had minor neurodevelopmental impairment, and 49 (75.4%) were judged to have had normal development. Compared with surviving infants without a major handicap, the group of infants who died and those with cerebral palsy had lower proportions of expected birth weight (0.766 +/- 0.1 as compared with 0.859 +/- 0.13, P =.029), head (0.869 +/- 0.07 as compared with 0.950 +/- 0.07, P =.05), and abdominal (0.793 +/- 0.04 as compared with 0.888 +/- 0.1, P =.001) circumference growth during latency period. In logistic regression analysis, lower-than-expected ultrasound measures of fetal abdominal circumference before birth (odds ratio 1.09; 95% confidence interval 1.01, 1.18) or of abdominal circumference growth during the latency period (odds ratio 1.1; 95% confidence interval 1.01, 1.2) were significantly associated with an increased likelihood of an infant neurodevelopmental abnormality at 2-year follow-up. In pregnancies complicated by preterm PROM, lower-than-expected measures of fetal size and fetal growth were associated with an increased rate of infant neurodevelopmental outcome at 2-year follow-up. II-2

Objectives: Serial measurements of sonographic fetal abdominal circumference (AC) are useful for monitoring fetal growth during pregnancy and are essential for predicting macrosomia. The study was aiming to compare the AC profiles of infants born to mothers with or without hyperglycemia in Chinese population.Subjects and methods: The “GDM Prevalence Study (GPS)” was a large study conducted in 22 hospitals in three large cities in China, which included 34,085 NGT (normal glucose tolerant) women, 8272 GDM (gestational diabetes mellitus) women and 729 DM (diabetes mellitus) women. A total of 116,740 scans and 103,377 valid AC measurements were performed for the NGT, GDM and DM groups at different gestational age. AC profiles and fetal growth rates at different stages of pregnancy were compared between different groups.Results: The overall AC growth rate (β) was higher in the macrosomia group than in the no macrosomia group in NGT (β =10.250 versus 9.541, p < .001), GDM (β = 10.572 versus 9.705, p < .001) and DM (β = 11.363 versus 9.924, p < .001) pregnancies. Significant differences were observed between NGT-macrosomia, GDM-macrosomia and DM-macrosomia. Significant differences were also noted between NGT-no macrosomia, GDM-no macrosomia and DM-no macrosomia women. Participants in NGT-macrosomia group exhibited larger AC values than NGT-no macrosomia group beginning at 21 gestational weeks, and GDM-macrosomia group exhibited larger AC values than GDM-no macrosomia group beginning at 22 gestational weeks. AC growth rate was higher in NGT-macrosomia and GDM-macrosomia groups than in the corresponding no macrosomia groups between 22 and 30 gestational weeks.Conclusions: The overall AC growth rates are higher in macrosomia group compared to the no macrosomia group in NGT, GDM as well as DM participants. The significant difference of AC growth rates in NGT-macrosomia and GDM-macrosomia indicate the possible differential underlying mechanisms in developing macrosomia with or without hyperglycemia exposure. Our study demonstrate that larger fetal AC measurements around 21–22 weeks are associated with subsequent diagnosis of macrosomia, suggesting that macrosomia management should be initiated much earlier than we thought.

Early fetal growth: concepts and pitfalls

Background Accurate assessment of fetal size is essential in providing optimal prenatal care. National Institute of Child Health and Human Development (NICHD) study from 2015 demonstrated that estimated fetal weight (EFW) differed significantly by race/ethnicity after 20 weeks. There is a large Somali population residing in Minnesota, many of whom are cared for at our maternal fetal medicine practice at the University of Minnesota. Anecdotally, we noticed an increased proportion of small-for-gestational age diagnoses within this population. We sought to use our ultrasound data to create a reference standard specific for this population and compare to currently applied references. Purpose We aimed to model fetal growth standards within a healthy Somali population between 16 and 40 weeks gestation, and address possible differences in the growth patterns compared with standards for non-Hispanic White, non-Hispanic Black, Hispanic, and Asian singleton fetuses published by the NICHD in the Fetal Growth Study. Materials and methods This is a retrospective cohort study using ultrasound data from 527 low risk pregnancies of Somali ethnicity at single tertiary care center between 2011 and 2017. A total of 1107 scans were identified for these pregnancies and maternal and obstetrical data were reviewed. Women 18–40 years of age with low-risk pregnancies and established dating consistent with first trimester ultrasound scan were included. Exclusion criteria were any maternal, fetal or obstetrical conditions known to affect fetal growth. Results Estimated fetal weight among Somali pregnancies differed significantly at some time points from the NICHD four ethnic groups, but generally the EFW graph curves crossed over at most time points between the study groups. At week 18, EFW was significantly larger than all other four ethnic groups (all p<.001), it was also significantly larger from the Hispanic, Black, and Asian ethnic groups at some time points between 18 and 27 weeks gestation (p < .05). Additionally, EFW among Somali pregnancies was significantly smaller than the Black and Asian ethnicity at 32 and 35–36 weeks and smaller than the White ethnicity at 30 and 38–39 weeks (p < .05). Abdominal circumference (AC) for the Somali population was significantly smaller than the other ethnic groups, especially than the White ethnicity at various time points across 16–40 weeks (p < .05). Femur and humerus length were significantly longer when compared to all other ethnic groups at most time points from 16 to 40 weeks of gestation (p < .05). Biparietal diameter (BPD) was significantly smaller than all other ethnic groups specifically at time of fetal survey (18 weeks) and at time of fetal growth assessment (32 weeks) (p < .05). Conclusions Significant differences in fetal growth standards were found between the Somali ethnicity and other ethnic groups (White, Black, Asian, and Hispanic) at various time points from 16 to 40 weeks of gestation. Racial/ethnic-specific standards improve the precision for evaluating fetal growth and may decrease the proportion of fetuses of Somali ethnicity labeled as small-for-gestational age.

Reappraisal of Fetal Abdominal Circumference in an Asian Population: Analysis of 50,131 Records

Aims(1) To identify which ultrasound parameters can be most accurately measured and which best reflect ovine fetal weight during late pregnancy. (2) To formulate regression equations for fetal weight estimation...

The placenta is a sprightliness of fetus in utero, as it function for normal growth &amp; development of fetus. So if the growth of fetus is compromised it can be detected by the measurement of placenta. The purpose of our study was to determine normal range of placental thickness &amp;its correlation with gestational age in second &amp; third trimester.100 pregnant females between 14th to 38th weeks of gestation referred from antenatal clinics to the department of Radio diagnosis in association with the department of Anatomy. Females aged below 35 years without any medical complications were included for routine antenatal ultrasound. Study was carried out on seimen Acuson 300 ultrasound machineusing3.5MHZ convex probe. The placental thickness was measured at the level of umbilical cord insertion in both longitudinal &amp;transverse direction. The ultrasonic gestational age is determined by measuring the Biparital Diameter, Head Circumference, Abdominal Circumference &amp; Femur Length. The mean value of the placental thickness along with the respective standard deviation were calculated for different gestational weeks and compared with gestational age statistically in order to and its correlation. The maximum mean placental thickness is19.82±3.42 at 19th week of gestation &amp;38.9±0.04 at 38th week of gestation with a signifcant positive correlation between placental thickness and gestational age r=0.82 &amp;r=0.79 in second and third trimester. Placental thickness can be used as an accurate sonographic indicator in assessment of gestational age due to its linear correlation.

Many ultrasonologists feel that if they are unable to obtain a BPD measurement at the time of an ultrasound examination that they have somehow failed to do an adequate job. However, from the information outlined in this chapter, it can be seen that the biparietal diameter is only one measurement that can be taken of the fetus in order to estimate gestational age. Furthermore, since the recognition of variability in fetal head shape, absolute reliance on measurement of the fetal biparietal diameter for estimation of gestational age has become much less common, especially after 20 weeks of gestation. The move toward measurement of several parts of the fetal anatomy has been called fetal biometry. The purpose of this approach is to evaluate body proportion and symmetry of growth of different organ systems, in the hope of elucidating subtle patterns which might be recognized as abnormal in very early stages when some form of prenatal management might improve reproductive outcome. Simultaneously, with the implementation of this approach to estimating age, a desire to inject an element of "quality control" into the obstetric ultrasound examination has come about. It has been found that measurement of more than one fetal parameter, in a sense, prevents overreliance on any single measurement, which, by itself, might mislead the clinician. While an error of clinically significant magnitude can be made in any measurement, it is unlikely that an error of the same magnitude, in "the same direction" of over or underestimation of the actual, would occur. Thus, there is an element of protection of the patient built into this approach which makes it appealing intuitively. However, it is uncertain that measurement of BPD, head circumference, abdominal circumference, and femur length will, in all cases, give a better estimate of gestational age than will measurement of the BPD alone. Recent data from Hadlock et al. showed that in 177 normal pregnancies, there was significant improvement in the ultrasound estimation of estimated date of delivery when two or more parameters were used to make that estimate rather than just BPD alone. Prior to 36 weeks, the optimal combination of parameters included the biparietal diameter, the abdominal circumference, and the femur length. However, after 36 weeks, the head circumference, abdominal circumference, and femur length gave the best estimate, with significant reduction in the mean errors, standard deviations, and size of maximum errors. Thus, it appears that the estimate using MFGP is both more accurate and precise than a single measurement.(ABSTRACT TRUNCATED AT 400 WORDS)

Background: In routine ultrasonography, the ultrasonologist measures the bi-parietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL) in estimating the gestational age (GA) and estimated date of delivery. However, as the pregnancy advances these parameters become increasingly unreliable in prediction of GA. Estimation of GA in late second and third trimester accurately still a problem till now. Fetal kidney has been shown a steady growth of 1.7 mm fortnightly (every 2 weeks) along pregnancy and is unaffected by growth abnormalities. Many studies have reported that fetal kidney length (FKL) correlates with the gestational age in late trimester very strong. The study aimed to assess the accuracy of the gestational age estimated by mean fetal kidney length compared to multiple growth parameters like BPD, HC, AC & FL in addition to the actual gestational age derived from the reliable last menstrual period. Methods: Cross sectional hospital based study, was conducted at ultrasound unit; department of Obstetrics and Gynecology, Faculty of Medicine, Ain Shams University from the period of July 2018 to December 2018. A total number of 115 Pregnant women at their third trimester by reliable LMP attended antenatal care clinic at Ain-Shams University Hospital and consented to participate in this study. Every woman was subjected to: Expected date of delivery was calculated according to Naegle’s formula: Ultrasonography: Fetal biometry and estimated date of delivery (EDD) by assessment of BPD, HC, FL & AC. Expected fetal weight measured by Hadlock formula. Fetal lie and presentation. Exclusion of fetal anomalies. Measurement of both right & left fetal kidney length. Results: In this study, 255 participants were recruited and assessed for eligibility, 125 women were allocated to perform obstetric ultrasound just 115 completed and were included in the final analysis. The current study found that there was a highly significant positive correlation between gestational age (according to ultrasound parameters) and KL, BDP, HC, AC and FL but Kidney length was the most correlated parameter. Also this study found that there was significant positive correlation between gestational age (according to LMP) and gestational age estimated by BPD, HC, AC, FL and KL with the most significant positive correlation being with KL. Also this study found that there was no significant difference (matched) in KL and Gestational age compared to other parameters. This means that KL is the most accurate parameter for Estimating Gestational age, correlation between MKL and GA by LMP (r = 0.951, p = 0.000) the most significant correlation. In this study, no significant difference was found between gestational age estimated by KL and gestational age in all stages of pregnancy. This means that KL remains accurate as a predictor for gestational age regardless stage of pregnancy. Conclusion: Kidney length can be used as an individual parameter in estimating gestational age.

This study determines whether a machine-learning model integrating sonographic biometry with maternal clinical parameters improves prediction of large-for-gestational-age (LGA) compared with Hadlock's EFW formula. We conducted a retrospective cohort study including all singleton live births at ≥32 gestational weeks at a tertiary medical center. Predictors comprised biparietal diameter, abdominal circumference, femur length, maternal demographics and anthropometrics, obstetric history, chronic and gestational morbidity, and glucose values from screening and diagnosis. A CatBoost gradient-boosting model estimated the probability of LGA (birthweight ≥90th percentile). Performance was compared with Hadlock's EFW using area under the curve (AUC) and detection at a fixed 10% false-positive rate. A prespecified subgroup analysis evaluated pregnancies with pregestational or gestational diabetes. Performance was assessed with fivefold cross-validation; calibration and utility were examined by decision curve analysis. Among 31 531 parturients, 18.17% delivered an LGA neonate. The model achieved an AUC of 0.946 (95% confidence interval [CI], 0.938-0.955), significantly outperforming Hadlock's EFW (AUC 0.867; 95% CI, 0.854-0.881; P = 0.01) and yielding a higher detection rate at a 10% false-positive rate (79% vs. 63%). The most influential contributors were abdominal circumference, gestational age at delivery, fetal sex, and maternal age. In 3871 diabetic pregnancies, among whom 24% delivered LGA, performance remained high (AUC 0.890; 95% CI, 0.847-0.918) and exceeded Hadlock's formula (AUC 0.820; 95% CI, 0.772-0.863; P = 0.02). A predictive algorithm, incorporating sonographic and non-sonographic features, as developed here, achieved superior accuracy compared to the traditional EFW formula in predicting LGA neonates, in both general and diabetic pregnant populations.

OBJECTIVE—To determine the contribution of maternal glucose and lipids to intrauterine metabolic environment and fetal growth in pregnancies with gestational diabetes mellitus (GDM).RESEARCH DESIGN AND METHODS—In 150 pregnancies, serum triglycerides (TGs), cholesterol, free fatty acids (FFAs), glycerol, insulin, and glucose were determined in maternal serum and cord blood during the 3rd trimester. Maternal glucose values came from oral glucose tolerance testing and glucose profiles. Measurements of fetal abdominal circumference (AC) were performed simultaneously with maternal blood sampling and birth weight, and BMI and neonatal fat mass were obtained following delivery.RESULTS—Maternal TGs and FFAs correlated with fetal AC size (at 28 weeks: triglycerides, P = 0.001; FFAs, P = 0.02), and at delivery they correlated with all neonatal anthropometric measures (FFA: birth weight, P = 0.002; BMI, P = 0.001; fat mass, P = 0.01). After adjustment for confounding variables, maternal FFAs and TGs at delivery remained the only parameters independently related to newborns large for gestational age (LGA) (P = 0.008 and P = 0.04, respectively). Maternal FFA levels were higher in mothers with LGA newborns than in those with appropriate for gestational age (AGA) newborns (362.8 ± 101.7 vs. 252.4 ± 10.1, P = 0.002). Maternal levels of TGs, FFAs, and glycerol at delivery correlated with those in cord blood (P = 0.003, P = 0.004, and P = 0.005, respectively). Fetal triglyceride and cholesterol levels were negatively correlated with newborn birth weight (P = 0.001), BMI (P = 0.004), and fat mass (P = 0.001). TGs were significantly higher in small for gestational age (SGA) newborns compared with AGA or LGA newborns, while insulin-to-glucose ratio and FFAs were the highest in LGA newborns.CONCLUSIONS—In well-controlled GDM pregnancies, maternal lipids are strong predictors for fetal lipids and fetal growth. Infants with abnormal growth seem to be exposed to a distinct intrauterine environment compared with those with appropriate growth.

Our aim was to investigate the relation between PBDEs and fetal growth or newborn anthropometry in a Spanish cohort (2003–2008). PBDE congeners (BDE-47, -99, -153, -154, and -209) were determined in serum of 670 mothers at gestational week 12 and in 534 umbilical cord samples. Abdominal circumference (AC), estimated fetal weight (EFW), femur length (FL), and biparietal diameter (BPD) during gestation were measured by ultrasounds. At birth, weight (BW), head circumference (HC), and length (BL) were also measured. We assessed growth in the intervals between 12–20 and 20–34 weeks of gestation and size at birth by standard deviation (SD)-scores adjusted for constitutional characteristics. We conducted multivariate linear regression analyses between PBDE congeners and their sum (ΣPBDEs) and outcomes. We found statistically significant inverse associations between ΣPBDEs and AC, EFW, and BPD at weeks 20–34 and HC at birth. Regarding congeners, the association was clearer with BDE-99, with inverse associations being found with AC, EFW, and BPD at weeks 20–34, and with BW and HC at delivery. These outcomes decreased between 1.3% and 3.5% for each 2-fold PBDE increase. Concerning matrices, we found statistically significant inverse associations with BPD, HC, and BW when using maternal serum, and for AC and EFW with cord serum. In conclusion, PBDEs may impair fetal growth in late pregnancy and reduce birth size.

Female fetuses, on average, weigh less than male fetuses at all gestational ages. The purpose of this study was to compare female and male fetuses in terms of intrauterine ultrasound growth measurements and to develop gestational-age-related charts based on a computerized perinatal database. This was a retrospective study of unselected women in the second and third trimesters of pregnancy, who had a normal scan at 10-14 weeks. Data analysis was performed using measurements obtained from a mixed-race population of 4234 women, who underwent 5198 ultrasound examinations. The scans were performed by four trained sonographers, according to a standardized protocol. Routine measurements included biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL). The main end-points were sex- and race-specific differences in fetal biometry, which were also used to estimate fetal weight. The base-line demographic characteristics and risk factors were comparable in female and male fetuses. Significant differences in fetal BPD, HC, AC and estimated fetal weight, but not FL, were seen between male and female fetuses. Centile charts for each of these variables were constructed for both male and female fetuses. This study suggests that small but consistent sex-related differences in prenatal BPD, HC and AC measurements are established by as early as 15 weeks of gestation. The use of sex-specific nomograms may improve the prenatal assessment of fetal growth as well as the diagnosis of structural abnormalities.

A conditional standard for the customized fetal growth trajectory in twin pregnancy

Longitudinal lipidomic profiles during pregnancy and associations with neonatal anthropometry: findings from a multiracial cohort