Prenatal exposure to fine particulate matter and fetal growth: a cohort study from a velocity perspective

Fetal Growth Velocity-A Breakthrough in Intrauterine Growth Assessment?

The pursuit of assessing fetal well-being in obstetrical practice remains a central tenet, propelling ongoing endeavors to explore innovative markers and diagnostic methodologies aimed at prognosing potential perinatal adversities. Deviations from standard patterns of intrauterine growth, whether exhibiting excessive or insufficient trajectories, stand as pivotal indices hinting at underlying pathophysiological processes or heightened concurrent medical conditions. Initiatives like the Delphi consensus and the INTERGROWTH-21st project strive to refine diagnostic criteria and establish international standards for fetal growth assessment. This article aims to present the current knowledge regarding the assessment of abnormal growth, including novel methods such as growth velocity. Integrating fetal growth velocity assessment into perinatal care protocols holds promise in enhancing diagnostic precision. Growth velocity, involving changes in fetal size over a given period, offers insights into distinguishing between constitutional and pathological growth abnormalities. Various methodologies and models have been proposed to evaluate growth velocity, with notable advancements in understanding fetal growth patterns across different trimesters. It is believed that accelerated and reduced growth velocity may be a sensible parameter in the detection of fetal growth restriction (FGR), small-for-gestational-age (SGA) fetuses, large-for-gestational-age (LGA) fetuses and macrosomic fetuses as well as appropriate-for-gestational age (AGA) fetuses that encounter problems with growth continuation. Recent studies found that changes in growth velocity reflect the risk of adverse perinatal outcomes (APOs). Future directions in fetal health research aim to elucidate the long-term consequences of abnormal fetal growth velocity on neurodevelopmental outcomes, highlighting the critical role of early assessment and intervention.

Prenatal ambient air pollutants exposure and the risk of stillbirth in Wuhan, central of China

BACKGROUND

The existing studies on the relationships of prenatal ambient air pollutants exposure with stillbirth in the Chinese population are very limited and the results are inconsistent, and the susceptible windows and potential modifiers for air pollutants exposure on stillbirth remain unanswered.

OBJECTIVE

We aimed to determine the relationships between exposure to ambient air pollutants and stillbirth, and explored the susceptible windows and potential modifiers for air pollutants exposure on stillbirth.

METHODS

A population-based cohort was established through the Wuhan Maternal and Child Health Management Information System involving 509,057 mother-infant pairs in Wuhan from January 1, 2011 through September 30, 2017. Personal exposure concentrations of fine particles (PM_2.5), inhalable particles (PM₁₀), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), carbon monoxide (CO), and ozone (O₃) for mothers were estimated based on their residential address during pregnancy using the inverse distance weighted (IDW) method. We used the logistic regression models to determine the associations at different stages of pregnancy with adjustment for confounding factors.

RESULTS

There were 3218 stillbirths and 505,839 live births among the participants. For each 100 μg/m³ of CO and 10 μg/m³ of O₃ increase in the first trimester (conception to 13⁺⁶ weeks), the risk of stillbirth increased by 1.0% (OR = 1.01, 95%CI: 1.00-1.03) and 7.0% (OR = 1.07, 95%CI: 1.05-1.09). In the second trimester (14 weeks-27⁺⁶ weeks), PM_2.5, PM₁₀, CO, and O₃ exposure were closely related to the risk of stillbirth (P＜0.05). In the third trimester (28 weeks to delivery), for each 10 μg/m³ increase in exposure concentrations of PM_2.5, SO₂, and O₃, the risk of stillbirth increased by 3.4%, 5.9%, and 4.0%, respectively. O₃ exposure was positively relevant to the risk of stillbirth (OR = 1.11, 95%CI: 1.08-1.14) in the whole pregnancy. Exposure to NO₂ was not significantly associated with the risk of stillbirth. Stratified analyses also presented a stronger association among mothers with boy infant, living in rural areas, delivering between 2011 and 2013, and those without gestational hypertension and history of stillbirth.

CONCLUSION

This study provides evidence that maternal exposure to PM_2.5, PM₁₀, SO₂, CO, and O₃ were related to the increased risk of stillbirth. Both the second and third trimesters might be vital susceptible windows for stillbirth. Our findings expand the evidence base for the important impacts of air pollution on fetal growth.

The associations of prenatal exposure to PM2.5 and its constituents with fetal growth: A prospective birth cohort in Beijing, China

BACKGROUND

Limited studies investigated the association of prenatal exposure to PM_2.5 and fetal growth measured by ultrasound with inconsistent results. No study evaluated the effect of PM_2.5 constituents on fetal growth in utero. We aimed to investigated whether prenatal exposure to PM_2.5 and its constituents was associated with fetal growth measured by ultrasound.

METHODS

A total of 4319 eligible pregnant women in Peking University Birth Cohort in Tongzhou (PKUBC-T) were included in the study. Based on mothers' residential addresses, we estimated prenatal PM_2.5 concentrations with a satellite-based spatiotemporal model and PM_2.5 constituents concentrations with a modified Community Multiscale Air Quality model. Fetal growth parameters of abdominal circumference (AC), head circumference (HC), and femur length (FL) were measured by ultrasound and then estimated fetal weight (EFW) was calculated. We calculated sex and gestational age-specific fetal growth Z-score and then defined the corresponding fetal undergrowth. Generalized estimating equation was used to investigate the association of PM_2.5 and its constituents with fetal growth Z-score and fetal undergrowth.

RESULTS

Prenatal exposure to PM_2.5, OC, EC, SO₄^2-, NH₄⁺, or NO₃^- was consistently associated with decreased Z-scores of fetal growth parameters (AC, HC, FL, EFW). One IQR increase of PM_2.5, OC, EC, SO₄^2-, NH₄⁺, or NO₃^- was associated with -0.183 [95% confident interval (CI): -0.225, -0.141], -0.144 (95%CI: -0.181, -0.107), -0.123 (95%CI: -0.160, -0.085), -0.035 (95%CI: -0.055, -0.015), -0.095 (95%CI: -0.126, -0.064), and -0.124 (95%CI: -0.159, -0.088) decrease in EFW Z-score, respectively. Prenatal exposure to PM_2.5, OC, EC, SO₄^2-, NH₄⁺, or NO₃^- was also associated with higher risk of fetal AC, HC, FL or EFW undergrowth.

CONCLUSION

The study identified that prenatal exposure to PM_2.5 or its constituents was associated with impaired fetal growth. The findings provided evidence that control measures for PM_2.5 constituents should be implemented for further promoting fetal growth.

Characterization of ambient carbon monoxide and PM 2.5 effects on fetus development, liver enzymes and TSH in Isfahan City, central Iran

Ambient carbon monoxide (CO) and particulate matters (PMs) are two important air pollutants in urban areas with known impacts on fetuses. Hence, this study measured some biochemistry factors of 200 neonates with birth dates from January 19 to October 12, 2020, including the birth weight and height and the serum levels of ALT, AST, ALP, GGT, and TSH. The Support Vector Machine-fitted land-use regression approach was used to predict the spatio-temporal variability of intra-urban PM 2.5 and CO concentrations by month during the pregnancy period of the cases employing 5 variables of Digital Elevation Model (DEM), slope, and distance from Compressed Natural Gas (CNG) stations, Bus Rapid Transit (BRT) stations, and mines and industries. Spearman correlation analysis (p < 0.05) was performed between the neonate indices and mean monthly PM 2.5 and CO concentrations at the exact residential address of maternal cases and their nearby areas in 250, 500, 1000, 1500, and 2000 m-radius buffer rings. All modeling efforts succeeded in predicting CO and PM 2.5 levels with acceptable adjusted r² values. Northern Isfahan had relatively higher CO and PM 2.5 concentrations due to its adjacency to low-vegetated open lands and its high traffic load as compared to southern areas. The correlation results between the neonate biochemistry indices and mean PM 2.5 and CO concentrations were mostly positive in most buffer rings, especially in the >500 m-radius buffer rings for PM 2.5 and in the 2000 m-radius rings for CO. Although the correlation results of PM 2.5 followed a detectable trend in the buffer rings, the associations between CO and the neonate biochemistry indices differed significantly between the buffer rings. Results showed that increasing mean monthly concentration of CO and PM 2.5 may stimulate further production of liver enzymes while decreasing the birth weight and height.

Short-term ambient nitrogen dioxide exposure is associated with increased risk of spontaneous abortion: A hospital-based study

There are increasing concerns with regard to spontaneous abortion (SAB), the loss of pregnancy without external intervention before 20 weeks of gestation, among reproductive-aged women. To date, limited evidence is available concerning the association between SAB and air pollutants, especially in developing countries. Daily baseline outpatient data for SAB from January 1, 2014, to December 31, 2018 (1826 days) were obtained in Chongqing, a metropolis of southwest China. The over-dispersed Poisson generalized additive model with control of meteorological conditions and day of week was used to estimate the short-term effects of ambient air pollution on the daily number of SAB outpatients. A total of 42,334 SAB outpatient visits for SAB were recorded. No statistically significant association was observed between SAB and CO, PM2.5, PM10, O3, and SO2. The positive association only appeared for NO2: positive associations between SAB and NO2 were observed in both single-day models (lag 0, lag 1, lag 3, and lag 4) and cumulative exposure models (lag 01, lag 03, and lag 05) and the most significant effects were observed at lag 05 (3.289%; 95% CI: 1.568%, 5.011%). Moreover, the women with higher ages (30-39 and > 39) were more sensitive than those with lower ages (18-29), and the effect estimates were more evident in cool seasons. Collectively, our results suggested that short-term NO2 exposure was associated with higher risk of SAB, especially in elder women and cool seasons, which may contribute to further understand the role of air pollution on SAB and other adverse obstetric outcomes.