BACKGROUND: Fetal weight estimation at term is a challenging clinical task.
OBJECTIVE: To evaluate the association between peripheral white blood cell (WBC) count of the laboring women and neonatal birth weight (BW) for term uncomplicated pregnancies.
METHODS: We conducted a single-center, retrospective cohort study (2006-2021) of women admitted in the first stage of labor or planned cesarean delivery. Complete blood counts were collected at admission. BW groups were categorized by weight (grams): < 2500 (group A), 2500-3499 (group B), 3500-4000 (group C), and > 4000 (group D). Two study periods were used to evaluate the association between WBC count and neonatal BW.
RESULTS: There were a total of 98,632 deliveries. The dataset analyses showed a lower WBC count that was significantly and linearly associated with a higher BW; P for trend < 0.001 for women in labor. The most significant association was noted for the > 4000-gram newborns; adjusted odds ratio 0.97, 95% confidence interval 0.96-0.98; P < 0.001; adjusted for hemoglobin level, gestational age, and fetal sex. The 2018-2021 dataset analyses revealed WBC as an independent predictor of macrosomia with a significant incremental predictive value (P < 0.0001). The negative predictive value of the WBC count for macrosomia was significantly high, 93.85% for a threshold of WBC < 10.25 × 103/µl.
CONCLUSIONS: WBC count should be considered to support the in-labor fetal weight estimation, especially valuable for the macrosomic fetus.

BACKGROUND: Vitamin D deficiency, a common occurrence among pregnant women, is an emerging public health concern worldwide. According to research, prenatal vitamin D deficiency is associated with various complications. This study assessed the vitamin D status of pregnant women in Yanbian, Jilin Province, as well as the correlation and predictive value of their vitamin D levels in relation to gestational length (weeks) and fetal weight, aiming to provide a basis for clinical diagnosis and treatment.
METHODS: We conducted a population-based retrospective study involving 510 pregnant women from August 2019 to October 2022. Blood samples were collected at 16-20 weeks of gestation for the detection of serum vitamin D levels. Statistical analyses were performed using SPSS 28.0 and R 4.1.0 software. Multifactorial logistic regression analysis was employed to establish whether each variable was a risk factor for deliveries at ≤ 38 gestational weeks and low fetal weight. These results were used to construct a risk prediction model, and the model\'s predictive efficacy was evaluated. Results or differences with p < 0.05 were considered statistically significant.
RESULTS: Multifactorial logistic regression analysis revealed that vitamin D ≤ 14.7 ng/mL(OR: 1.611; 95% CI: 1.120-2.318; P = 0.010), Bone Mineral Density (BMD) T-value ≤-1(OR: 1.540; 95%CI: 1.067-2.223; P = 0.021), and gestational hypertension(OR: 7.173; 95% CI: 1.482-34.724; P = 0.014) were the independent risk factors for deliveries at ≤ 38 gestational weeks. Additionally, vitamin D ≤ 14.7 ng/mL(OR: 1.610; 95%CI: 1.123-2.307; P = 0.009), BMD T-value ≤ -1(OR: 1.560; 95%CI: 1.085-2.243; P = 0.016), and gestational hypertension(OR: 4.262; 95% CI: 1.058-17.167; P = 0.041) were the independent risk factors for low fetal weight (< 3400 g).
CONCLUSIONS: This study revealed that low vitamin D levels are an independent risk factor for a short gestational length and low fetal weight. Prenatal low BMD T-value and comorbid hypertensive disorders were also found to increase the risk of a short gestational length and low fetal weight.

BACKGROUND: Maternal genetic risk of type 2 diabetes (T2D) has been associated with fetal growth, but the influence of genetic ancestry is not yet fully understood. We aimed to investigate the influence of genetic distance (GD) and genetic ancestry proportion (GAP) on the association of maternal genetic risk score of T2D (GRST2D) with fetal weight and birthweight.
METHODS: Multi-ancestral pregnant women (n = 1,837) from the NICHD Fetal Growth Studies - Singletons cohort were included in the current analyses. Fetal weight (in grams, g) was estimated from ultrasound measurements of fetal biometry, and birthweight (g) was measured at delivery. GRST2D was calculated using T2D-associated variants identified in the latest trans-ancestral genome-wide association study and was categorized into quartiles. GD and GAP were estimated using genotype data of four reference populations. GD was categorized into closest, middle, and farthest tertiles, and GAP was categorized as highest, medium, and lowest. Linear regression analyses were performed to test the association of GRST2D with fetal weight and birthweight, adjusted for covariates, in each GD and GAP category.
RESULTS: Among women with the closest GD from African and Amerindigenous ancestries, the fourth and third GRST2D quartile was significantly associated with 5.18 to 7.48 g (weeks 17-20) and 6.83 to 25.44 g (weeks 19-27) larger fetal weight compared to the first quartile, respectively. Among women with middle GD from European ancestry, the fourth GRST2D quartile was significantly associated with 5.73 to 21.21 g (weeks 18-26) larger fetal weight. Furthermore, among women with middle GD from European and African ancestries, the fourth and second GRST2D quartiles were significantly associated with 117.04 g (95% CI = 23.88-210.20, p = 0.014) and 95.05 g (95% CI = 4.73-185.36, p = 0.039) larger birthweight compared to the first quartile, respectively. The absence of significant association among women with the closest GD from East Asian ancestry was complemented by a positive significant association among women with the highest East Asian GAP.
CONCLUSIONS: The association between maternal GRST2D and fetal growth began in early-second trimester and was influenced by GD and GAP. The results suggest the use of genetic GD and GAP could improve the generalizability of GRS.

UNASSIGNED: Evaluate the prevalence of macrosomic newborns (birth weight above 4000 grams) in a high-risk maternity from 2014 to 2019, as well as the maternal characteristics involved, risk factors, mode of delivery and associated outcomes, comparing newborns weighing 4000-4500 grams and those weighing above 4500 grams.
UNASSIGNED: This is an observational study, case-control type, carried out by searching for data in hospital\'s own system and clinical records. The criteria for inclusion in the study were all patients monitored at the service who had newborns with birth weight equal than or greater than 4000 grams in the period from January 2014 to December 2019, being subsequently divided into two subgroups (newborns with 4000 to 4500 grams and newborns above 4500 grams). After being collected, the variables were transcribed into a database, arranged in frequency tables. For treatment and statistical analysis of the data, Excel and R software were used. This tool was used to create graphs and tables that helped in the interpretation of the results. The statistical analysis of the variables collected included both simple descriptive analyzes as well as inferential statistics, with univariate, bivariate and multivariate analysis.
UNASSIGNED: From 2014 to 2019, 3.3% of deliveries were macrosomic newborns. The average gestational age in the birth was 39.4 weeks. The most common mode of delivery (65%) was cesarean section. Diabetes mellitus was present in 30% of the deliveries studied and glycemic control was absent in most patients. Among the vaginal deliveries, only 6% were instrumented and there was shoulder dystocia in 21% of the cases. The majority (62%) of newborns had some complication, with jaundice (35%) being the most common.
UNASSIGNED: Birth weight above 4000 grams had a statistically significant impact on the occurrence of neonatal complications, such as hypoglycemia, respiratory distress and 5th minute APGAR less than 7, especially if birth weight was above 4500 grams. Gestational age was also shown to be statistically significant associated with neonatal complications, the lower, the greater the risk. Thus, macrosomia is strongly linked to complications, especially neonatal complications.

BACKGROUND: Cynomolgus monkeys (Macaca fascicularis) are essential in biomedical research, including reproductive studies. However, the application of human estimated foetal weight (EFW) formulas using ultrasonography (USG) in these non-human primates is not well established.
OBJECTIVE: This study aims to evaluate the applicability of human EFW formulas for estimating foetal weight in cynomolgus monkeys at approximately 130 days of gestation.
METHODS: Our study involved nine pregnant cynomolgus monkeys. We measured foetal parameters, including biparietal diameter, head circumference, abdominal circumference and femur length using USG. The EFW was calculated using 11 human EFW formulas. The actual birthweight (ABW) was recorded following Cesarean section, the day after the EFW calculation. For comparing EFW and ABW, we employed statistical methods such as mean absolute percentage error (APE) and Bland-Altman analysis.
RESULTS: The ABW ranged between 200.36 and 291.33 g. Among the 11 formulas, the Combs formula showed the lowest APE (4.3%) and highest correlation with ABW (p < 0.001). Notably, EFW and ABW differences for the Combs formula were ≤5% in 66.7% and ≤10% in 100% of cases. The Bland-Altman analysis supported these results, showing that all cases fell within the limits of agreement.
CONCLUSIONS: The Combs formula is applicable for estimating the weight of cynomolgus monkey fetuses with USG at approximately 130 days of gestation. Our observations suggest that the Combs formula can be applied in the prenatal care and biomedical research of this species.

Objectives: Congenital diaphragmatic hernia (CDH) is defined as organ protrusion from the abdominal to the thoracic cavity. The Hadlock formula is the most commonly used tool for calculating estimated fetal weight (EFW). The anatomical nature of CDH usually leads to underestimation of the abdominal circumference, resulting in underestimation of fetal weight. Accurate weight estimation is essential before birth for counselling, preparation before surgery and ECMO. The research is made to compare the accuracy of Hadlock\'s formula and Faschingbauer\'s formula for fetal weight estimation in CDH fetuses population. Methods: In our study, we investigated differences between EFW and actual birthweight in 42 fetuses with CDH as compared to 80 healthy matched controls. EFW was calculated using the Hadlock formula and a recently introduced formula described by Faschingbauer et al., which was tailored for fetuses with CDH. Additionally, both of the formulas were adjusted for the interval between the ultrasound and delivery for both of the groups. Results: The majority of hernias were left-sided (92.8% vs. 7.2%). EFW adjusted for the interval between the ultrasound and delivery had the highest correlation with the actual birthweight in both, study group and controls. We compared the results for both tools and found the Hadlock formula to predict birthweight in CDH children with a 7.8 ± 5.5% error as compared to 7.9 ± 6.5% error for the Faschingbauer\'s formula. Conclusions: The Hadlock formula adjusted for the interval between the ultrasound and delivery is a more precise method of calculating EFW in fetuses with CDH. Routine biometry scan using Hadlock\'s formula remains reliable for predicting birthweight.

Rabbits are routinely used as a natural model of fetal growth restriction (FGR); however, no studies have confirmed that rabbits have FGR. This study aimed to characterize the fetoplacental unit (FPU) in healthy pregnant rabbits using diffusion-weighted MRI and stereology. A secondary objective of the study was to describe the associations among findings from diffusion-weighted MRI (DW-MRI), fetal weight measurement and histological analysis of the placenta.
Pregnant rabbits underwent DW-MRI under general anesthesia on embryonic day 28 of pregnancy. MR imaging was performed at 3.0 T. The apparent diffusion coefficient (ADC) values were calculated for the fetal brain, liver, and placenta. The placenta was analyzed by stereology (volume density of trophoblasts, the maternal blood space and fetal vessels). Each fetus and placenta were weighed. Two groups of fetuses were defined according to the position in the uterine horn (Cervix group versus Ovary group).
We analyzed 20 FPUs from 5 pregnant rabbits. Fetuses and placentas were significantly lighter in the Cervix group than in the Ovary group (34.7 ± 3.7 g vs. 40.2 ± 5.4 g; p = 0.02). Volume density analysis revealed that the percentage of fetal vessels, the maternal blood space and trophoblasts was not significantly affected by the position of the fetus in the uterine horn. There was no difference in ADC values according to the position of the fetus in the uterine horn, and there was no correlation between ADC values and fetal weight.
The findings of a multimodal evaluation of the placenta in a rabbit model of FGR suggested is not a natural model of fetal growth restriction.

Objective: To investigate the association of exposure to PM2.5 and its constituents during pregnancy and fetal growth and to further identify critical windows of exposure for fetal growth. Methods: We included 4 089 mother-child pairs from the Jiangsu Birth Cohort Study between January 2016 and October 2019. Data of general characteristics, clinical information, daily average PM2.5 exposure, and its constituents during pregnancy were collected. Fetal growth parameters, including head circumference (HC), abdominal circumference (AC), and femur length (FL), were measured by ultrasound after 20 weeks of gestation, and then estimated fetal weight (EFW) was calculated. Generalized linear mixed models were adopted to examine the associations of prenatal exposure to PM2.5 and its constituents with fetal growth. Distributed lag nonlinear models were used to identify critical exposure windows for each outcome. Results: A 10 μg/m3 increase in PM2.5 exposure during pregnancy was associated with a decrease of 0.025 (β=-0.025, 95%CI: -0.048- -0.001) in HC Z-score, 0.026 (β=-0.026, 95%CI: -0.049- -0.003) in AC Z-score, and 0.028 (β=-0.028, 95%CI:-0.052--0.004) in EFW Z-score, along with an increased risk of 8.5% (RR=1.085, 95%CI: 1.010-1.165) and 13.5% (RR=1.135, 95%CI: 1.016-1.268) for undergrowth of HC and EFW, respectively. Regarding PM2.5 constituents, prenatal exposure to black carbon, organic matter, nitrate, sulfate (SO42-) and ammonium consistently correlated with decreased HC Z-score. SO42- exposure was also associated with decreased FL Z-scores. In addition, we found that gestational weeks 2-5 were critical windows for HC, weeks 4-13 and 19-40 for AC, weeks 4-13 and 23-37 for FL, and weeks 4-12 and 20-40 for EFW. Conclusions: Our findings demonstrated that exposure to PM2.5 and its constituents during pregnancy could adversely affect fetal growth and the critical windows for different fetal growth parameters are not completely consistent.
目的： 探讨妊娠期PM2.5及其组分暴露对胎儿生长的影响，并进一步识别暴露效应窗口。 方法： 选取江苏出生队列2016年1月至2019年10月招募的4 089对母子对，收集其基线信息、妊娠期诊疗信息、妊娠期PM2.5及其组分暴露信息、妊娠满20周后的胎儿B超检查（头围、腹围、股骨长和估计体重）信息。利用广义线性混合模型进行暴露效应的估计，利用分布滞后非线性模型探讨暴露效应窗口。 结果： 妊娠期PM2.5暴露浓度每升高10 μg/m3，胎儿头围、腹围和估计体重Z评分分别减小0.025（β=-0.025，95%CI：-0.048~-0.001）、0.026（β=-0.026，95%CI：-0.049~-0.003）和0.028（β=-0.028，95%CI：-0.052~-0.004），头围和估计体重生长受限风险分别增加8.5%（RR=1.085，95%CI：1.010~1.165）和13.5%（RR=1.135，95%CI：1.016~1.268）。PM2.5组分中黑碳、有机物、硝酸盐、硫酸盐、铵盐暴露浓度升高均与头围Z评分减小显著相关，同时硫酸盐暴露的增加还与股骨长的Z评分减小有关。妊娠期PM2.5暴露影响胎儿头围生长效应窗口为第2~5周，腹围为第4~13周以及第19~40周，股骨长为第4~13周以及第23~37周，估计体重为第4~12周以及第20~40周。 结论： 妊娠期PM2.5及其组分暴露可能对胎儿生长产生不利影响，影响胎儿不同生长指标的效应窗口不完全一致。.

OBJECTIVE: Given the plausible mechanisms and the lacking of empirical evidence, the study aims to investigate how gestational sleep behaviors and the development of sleep disorders, such as restless legs syndrome, influence ultrasonographic measures of fetal growth.
METHODS: The study included 2457 pregnant women from the NICHD Fetal Growth Studies - Singletons (2009-2013), who were recruited between 8-13 gestational weeks and followed up to five times during pregnancy. Women were categorized into six groups based on their total sleep hours and napping frequency. The trajectory of estimated fetal weight from 10-40weeks was derived from three ultrasonographic measures. Linear mixed effect models were applied to model the estimated fetal weight in relation to self-reported sleep-napping behaviors and restless legs syndrome status, adjusting for age, race and ethnicity, education, parity, prepregnancy body mass index category, infant sex, and prepregnancy sleep-napping behavior.
RESULTS: From enrollment to near delivery, pregnant women\'s total sleep duration and nap frequency declined and restless legs syndrome symptoms frequency increased generally. No significant differences in estimated fetal weight were observed by sleep-napping group or by restless legs syndrome status. Results remained similar in sensitivity analyses and stratified analyses by women\'s prepregnancy body mass index category (normal vs. overweight/obese) or by infant sex.
CONCLUSIONS: Our data indicate that there is no association between sleep during pregnancy-assessed as total sleep duration and napping frequency, nor restless legs syndrome symptoms-and fetal growth from weeks 10 to 40 in healthy pregnant women.

OBJECTIVE: To compare ultrasound-assessed fetal head circumference (HC), abdominal circumference (AC), HC/AC ratio, and estimated fetal weight (EFW) in prediction of large-for-gestational-age (LGA) at birth in pregnancies affected by type 1 (T1DM) and type 2 (T2DM) diabetes.
METHODS: This retrospective cohort study included all women with T1DM and T2DM giving birth to singletons between 2010 and 2019 at Aalborg University Hospital, Denmark. Ultrasound scans were performed at 16, 20, 28 and 34 weeks of pregnancy. LGA was defined as birth weight deviation of 15% or greater from the expected for gestational age (≥90th centile). Prediction of LGA was assessed by logistic regression adjusted for maternal characteristics and glycated hemoglobin (HbA1c) and area under the receiver operating characteristics curve (AUC).
RESULTS: Among 180 T1DM pregnancies, 118 (66%) had an LGA neonate at birth. At 28 weeks of pregnancy, they were predicted with AUCHC/AC = 0.67, AUCAC = 0.85, and AUCEFW = 0.86. The multivariate analysis did not improve the predictive performance of the HC/AC ratio or AC. Among 87 T2DM pregnancies, 36 (41%) had an LGA neonate at birth. At 28 weeks, they were predicted with AUCHC/AC = 0.73, AUCAC = 0.83, and AUCEFW = 0.87. In T2DM, the multivariate analysis significantly improved the predictive performance for both HC/AC ratio and AC from 20 weeks of pregnancy.
CONCLUSIONS: In T1DM and T2DM pregnancies, LGA is characterized by a general fetal overgrowth including both AC and HC. Therefore, AC and EFW perform better than the HC/AC ratio in the prediction of LGA. In T2DM, as opposed to T1DM, the predictive performance was improved by the inclusion of maternal characteristics and HbA1c in the analysis.