OBJECTIVE: The length of newborns shows seasonal fluctuations, but the patterns of these fluctuations vary greatly. This study analyses the fluctuation in birth length by birth month and temporal changes in Austrian newborns from the 1984 to 2021 birth cohorts.
METHODS: A total of 2 317 927 singleton-term births between 1984 and 2021 in Austria were included in this retrospective population-based cohort study. A strict inclusion criterion was the Austrian citizenship of the mother. The effect of month of birth (MOB) on birth length was estimated using a multivariable linear model adjusting for maternal educational level, newborn sex, gestational age, year of birth (YOB) of the newborn, and parity of the mother.
RESULTS: Newborn length varied by MOB, but there was also a temporal trend. In the birth cohorts up to 2004, the longest newborns were born in February, while from 2008 onward, the longest birth lengths were observed in the summer months.
CONCLUSIONS: In this Austrian population-based sample, birth length shows nonrandom fluctuations by birth month. These patterns, however, varied considerably over time.

Background/Objectives: The utility of shear wave elastography (SWE) as an adjunct to ultrasound biometry and Doppler velocimetry for the examination of placental dysfunction and suboptimal fetal growth is unclear. To date, limited data exist correlating the mechanical properties of placentae with fetal growth. This study aimed to investigate the relationship between placental shear wave velocity (SWV) and ultrasound estimated fetal weight (EFW), and to ascertain if placental SWV is a suitable proxy measure of placental function in the surveillance of small-for-gestational-age (SGA) pregnancies. Methods: This prospective, observational cohort study compared the difference in placental SWV between SGA and appropriate-for-gestational-age (AGA) pregnancies. There were 221 women with singleton pregnancies in the study cohort-136 (61.5%) AGA and 85 (38.5%) SGA. Fetal biometry, Doppler velocimetry, the deepest vertical pocket of amniotic fluid, and mean SWV were measured at 2-4-weekly intervals from recruitment to birth. Results: There was no difference in mean placental SWV in SGA pregnancies compared to AGA pregnancies, nor was there any relationship to EFW. Conclusions: Although other studies have shown some correlation between increased placental stiffness and SGA pregnancies, our investigation did not support this. The mechanical properties of placental tissue in SGA pregnancies do not result in placental SWVs that are apparently different from those of AGA controls. As this study did not differentiate between constitutionally or pathologically small fetuses, further studies in growth-restricted cohorts would be of benefit.

Despite the fact that labor depends on too many interacting factors and no parameter can fully predict its outcome, fetal cerebral Doppler has emerged as the most reliable tool for prediction, in contrast with fetal weight, which performs significantly worse in the last weeks of pregnancy. The importance of the cerebral Doppler follows the inverse pathway of fetal weight increasing its performance in the last weeks of pregnancy and reaching its highest ability prior to labor. A combination of cerebral flow, fetal weight, and selected clinical information may obtain moderate predictions of labor outcome, provided the interval to labor is not long.

It remains unclear whether and how maternal exposure to biomass fuel influences infant anthropometry or body proportionality at birth, which are linked to their survival, physical growth, and neurodevelopment. Therefore, this study seeks to explore the association between household-level exposure to biomass cooking fuels and infant size and body proportionality at birth among women in rural Bangladesh. A total of 909 women were derived from the Pregnancy Weight Gain study, which was conducted in Matlab, a rural area of Bangladesh. Infant\'s weight (g), length (cm), head circumference (cm), small for gestational age (SGAW), short for gestational age (SGAL), low head circumference for gestational age (SGAHC), ponderal index, and cephalization index at birth were the outcomes studied. Of the women, 721 (79.3%) were dependent on biomass fuel. Compared to infants born to mothers who used gas for cooking, those born to biomass users had lower weight (β - 94.3, CI - 155.9, - 32.6), length (β - 0.36, 95% CI - 0.68, - 0.04), head circumference (β - 0.24, CI - 0.47, - 0.02) and higher cephalization index (β 0.03, CI 0.01, 0.05) at birth. Maternal biomass exposure is more likely to lead to symmetric SGA, although there is evidence for some brain-sparing effects.

BACKGROUND: Chronic placental inflammation is a routinely diagnosed group of placental lesions that reflect immunologic dysfunction of the mother, fetus, or both.
METHODS: Complete placental pathology examinations were performed for all term births at New York Presbyterian- Brooklyn Methodist Hospital from January 2010-August 2016. Diagnoses were blinded except to gestational age. CPI lesions were marked as chronic choriodeciduitis, decidual plasma cells, chronic inflammation of basal plate with anchoring villitis, and chronic villitis.
RESULTS: In this cohort of term pregnancies, 257 (11.6 %) males and 218 (9.8 %) females had ≥1 CPI lesions. Chronic villitis was the most common (319 or 14 %), with chronic choriodeciduitis, decidual plasma cells, and chronic inflammation of basal plate with anchoring villitis in 94 (4 %), 69 (3 %) and 170 (8 %), respectively. In males, chronic villitis was associated with lower gestational adjusted birthweight and had no association with placental weight. In females, chronic villitis was associated with lower gestational adjusted birthweight, but the effect became nonsignificant after adjustment for placental weight.
CONCLUSIONS: In summary, CPI lesions\' incidence and association with birth weight vary by sex. Chronic villitis is associated with lower birthweight in females; this effect is completely mediated by placental weight. Chronic villitis showed a weak direct association of chronic villitis in males, but no association with lower placental weight in males. We suggest that differences between our results and previous publications reflect effects of sampling bias.

OBJECTIVE: To investigate the trimester-specific associations between maternal total physical activity level vs moderate-to-vigorous exercise and fetal growth disorders.
METHODS: We analyzed 2062 mother-neonate pairs participating in the longitudinal China Medical University Birth Cohort Study. The Pregnancy Physical Activity Questionnaire was used to assess the physical activity level of women during the three trimesters. A higher level of total physical activity was defined as meeting or exceeding the cohort-specific 75th percentile, and a higher level of exercise was defined according to the Physical Activity Guidelines for Americans. Fetal growth disorder was defined as small-for-gestational age (SGA) or large-for-gestational age (LGA) at birth.
RESULTS: Of the neonates included in this study, 7.1% were SGA and 15.5% were LGA. A higher level of total physical activity during the first trimester (adjusted relative risk (aRR), 0.62 (95% CI, 0.42-0.91)) and second trimester (aRR, 0.62 (95% CI, 0.41-0.95)) was associated with a lower risk of SGA, and a higher level of total physical activity during the third trimester was associated with a lower risk of LGA (aRR, 0.73 (95% CI, 0.54-0.97)). When analyzing physical activity by subtype, a higher level of occupational physical activity during the first and second trimesters was associated negatively with SGA risk, and higher levels of occupational and low-intensity physical activity during the first trimester were associated negatively with LGA risk. No significant association was found between maternal adherence to the Physical Activity Guidelines for Americans and risk of fetal growth disorders.
CONCLUSIONS: A higher total physical activity level during the first and second trimesters was associated with a decreased risk of SGA, whereas a higher total physical activity level in the third trimester was associated with a decreased risk of LGA. Pregnant women should be advised to increase their total physical activity levels instead of focusing on engaging in only moderate-to-vigorous exercise. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

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.

BACKGROUND: The impacts of maternal depression during mid-to-late pregnancy on fetal growth have been extensively investigated. However, the association between maternal depression during early pregnancy and fetal intrauterine growth are less clear.
METHODS: A prospective study comprised 23,465 eligible pregnant women and their offspring was conducted at a hospital-based center in Shanghai. Prenatal depression was assessed used using Patient Health Questionnaire (PHQ-9) before 14 gestational weeks. Differences in fetal growth trajectory of different maternal depressive statuses during three periods (16-23, 24-31, and 32-41 gestational weeks) were compared using a multilevel model with fractional polynomials.
RESULTS: Women with depressive symptoms during early pregnancy had higher longitudinal fetal trajectories, with an estimated increase in fetal weight (β = 0.33; 95 % CI, 0.06-0.61), compared to those without depressive symptoms. Increases in fetal abdominal circumference among women with depressive symptoms were observed before 23 gestational weeks. Offspring born to mothers with early pregnancy depression had a significantly higher birth weight of 14.13 g (95 % CI, 1.33-27.81 g) and an increased risk of severe large size for gestational age (adjusted odds ratio [aOR], 1.64; 95 % CI, 1.32-2.04) and macrosomia (aOR, 1.21; 95 % CI, 1.02-1.43).
CONCLUSIONS: Self-rated scale was used to assess depressive symptoms rather than clinical diagnosis. And Long-term effects of early pregnancy depression on offspring were not explored.
CONCLUSIONS: The study revealed an association between maternal depression during early pregnancy and increased fetal biometrics, higher birth weight, and an elevated risk of severe large size for gestational age and macrosomia.

BACKGROUND: In recent years, with benefits from the continuous improvement of clinical technology and the advantage of fertility preservation, the application of embryo cryopreservation has been growing rapidly worldwide. However, amidst this growth, concerns about its safety persist. Numerous studies have highlighted the elevated risk of perinatal complications linked to frozen embryo transfer (FET), such as large for gestational age (LGA) and hypertensive disorders during pregnancy. Thus, it is imperative to explore the potential risk of embryo cryopreservation and its related mechanisms.
METHODS: Given the strict ethical constraints on clinical samples, we employed mouse models in this study. Three experimental groups were established: the naturally conceived (NC) group, the fresh embryo transfer (Fresh-ET) group, and the FET group. Blastocyst formation rates and implantation rates were calculated post-embryo cryopreservation. The impact of FET on fetal growth was evaluated upon fetal and placental weight. Placental RNA-seq was conducted, encompassing comprehensive analyses of various comparisons (Fresh-ET vs. NC, FET vs. NC, and FET vs. Fresh-ET).
RESULTS: Reduced rates of blastocyst formation and implantation were observed post-embryo cryopreservation. Fresh-ET resulted in a significant decrease in fetal weight compared to NC group, whereas FET reversed this decline. RNA-seq analysis indicated that the majority of the expression changes in FET were inherited from Fresh-ET, and alterations solely attributed to embryo cryopreservation were moderate. Unexpectedly, certain genes that showed alterations in Fresh-ET tended to be restored in FET. Further analysis suggested that this regression may underlie the improvement of fetal growth restriction in FET. The expression of imprinted genes was disrupted in both FET and Fresh-ET groups.
CONCLUSIONS: Based on our experimental data on mouse models, the impact of embryo cryopreservation is less pronounced than other in vitro manipulations in Fresh-ET. However, the impairment of the embryonic developmental potential and the gene alterations in placenta still suggested it to be a risky operation.

BACKGROUND: Organophosphate esters (OPEs) exposure could affect offspring health. However, the underlying mechanisms are not well documented.
OBJECTIVE: Based on a birth cohort study, we aimed to investigate the associations among gestational OPEs exposure, placental DNA methylation levels of peroxisome proliferator-activated receptor (PPAR) signaling pathway-related genes, and fetal growth.
METHODS: We measured the concentrations of eight OPE metabolites in maternal urine samples and neonatal anthropometric measurements in 733 mother-child pairs. In 327 placental samples, we assessed the DNA methylation levels of 14 genes which were involved in the PPARs signaling pathway and expressed in placenta. Multiple linear regression models were used to examine the associations of OPEs exposure with placental DNA methylation, and of OPEs and placental DNA methylation with neonatal anthropometric measurements. Causal mediation analyses were conducted to examine the potential mediating role of placental DNA methylation in the pathway between OPEs exposure and fetal growth.
RESULTS: We observed a general pattern of OPEs exposure being associated with hypermethylation of candidate genes, with statistically significant associations identified for several OPEs with RXRA, ACAA1, ACADL, ACADM, PLTP, and NR1H3 methylation. Further, gestational exposure to BCIPP, DPP, BBOEP, ∑NCl-OPEs, and ∑OPEs tended to be associated with lower anthropometric measurements, with more significant associations observed on arm circumference, and abdominal and back skinfold thickness. Notably, RXRA, ACAA1, ACOX1, CPT2, ACADM, and NR1H3 methylation tended to be associated with lower neonatal anthropometric measurements, especially for abdominal and back skinfold thickness. Moreover, mediation analyses showed that 19.42 % of the total effect of DPP on the back skinfold thickness was mediated by changes in RXRA methylation, and there was a significant indirect effect of RXRA methylation.
CONCLUSIONS: Gestational OPEs exposure could disrupt the placental DNA methylation levels of PPAR signaling pathway-related genes, which might contribute to the effect of OPEs on fetal growth.