Impact of isolated single umbilical artery on pregnancy outcome and delivery in full-term births

Risk of adverse pregnancy outcome in isolated single umbilical artery diagnosed at the mid-trimester anomaly scan: a large Danish retrospective cohort study

OBJECTIVE

To examine the association of isolated single umbilical artery (iSUA) confirmed at the mid-trimester anomaly scan and adverse pregnancy outcome and congenital malformations with up to 10 years postnatal follow up.

METHODS

This retrospective cohort study included 116,501 singleton pregnancies consecutively enrolled in first trimester screening for aneuploidies and mid-trimester anomaly scan at three University Hospitals in the Capital Region of Copenhagen, Denmark.Data from the Danish Fetal Medicine Database (2008-2017) were verified by manually scrutinizing pre- and postnatal records. The main outcomes of interest were intrauterine fetal demise (IUFD), small for gestational age (SGA), preterm delivery, cesarean section and unrecognized pre- and postnatal congenital malformations.

RESULTS

In total, 775 pregnancies with iSUA were identified. Isolated SUA were associated with a significantly increased risk of IUFD (OR 4.16, 95% CI 2.06-8.44), SGA < 3^rd centile (aOR 2.41, 95% 1.85-3.14) and SGA < 10^th centile (aOR 1.84, 95% CI 1.53-2.21), but not with preterm delivery or cesarean section. The laterality of the missing artery was not associated with SGA. In total, 4.3% of pregnancies with iSUA had unrecognized congenital malformations. 1.5% with iSUA had congenital cardiovascular malformations, which were considered minor.

CONCLUSION

Isolated SUA is associated with IUFD and SGA, supporting surveillance during third trimester. If, during the mid-trimester scan, the sonographer achieves thorough, extended cardiac views and finds no additional malformation other than SUA, fetal echocardiography seems not to be needed.

Prevalence of single umbilical artery, clinical outcomes and its risk factors: A cross-sectional study

Background

Single umbilical artery (SUA) is found in 0.5–6% of all pregnancies worldwide. Although the association of SUA with some congenital malformations is mainly accepted, its effect on pregnancy/neonatal outcomes is still controversial.

Objective

This is the first study aimed to approximate the SUA prevalence in southern part of Iran. SUA epidemiologic features accompanied by some of its effects on pregnancy/neonatal outcomes are investigated as well.

Materials and Methods

In this cross-sectional study, data from two referral centers in Southern Iran were analyzed. In total, 1,469 pregnancies, fetuses, and neonates were examined for epidemiological features associated with SUA. SUA was confirmed by pathological examination, while congenital anomalies were diagnosed by clinical, ultrasound, and echocardiographical examinations. Data on pregnancy outcome were recorded based on the patients' medical records.

Results

The prevalence of SUA was 3.47% (95% CI: 2.6–4.6%). Fetal anomalies including renal, cardiac, and other congenital anomalies, intrauterine fetal death, early neonatal death, low birth weight, low placental weight, and preterm birth were significantly higher in the SUA group (OR = 68.02, 31.04, 16.03, 3.85, 11.31, 3.22, 2.70, and 2.47, respectively). However, the maternal multiparity was lower in the SUA group (OR = 0.65; 95% CI: 0.44–0.98).

Conclusion

A significant association was observed between SUA and increased risk of intrauterine fetal death and early neonatal death, as well as low birth weight and preterm birth. Obstetrical history of the mother like parity was identified as an important predictor of SUA. Further investigations are suggested on risk stratification of neonates in this regard.

Isolated Single Umbilical Artery as a Risk Factor for Urinary Tract Infections in Childhood

OBJECTIVE

This study aimed to determine whether isolated single umbilical artery (iSUA), even absent identifiable genitourinary (GU) abnormalities, increases the risk of GU infection during childhood.

STUDY DESIGN

Retrospective population-based comparison of fetuses with iSUA versus normal three-vessel cords. Fetuses with growth restriction, prematurity, multiple gestations, and anatomical or chromosomal anomalies were excluded. The primary outcome was hospital-associated GU infection during the first 18 years of life. Kaplan-Meier's survival curves were used to assess cumulative risk; Cox's multivariable models were used to adjust for confounders.

RESULTS

Among 227,599 term singleton deliveries, children with iSUA (n = 729) had a higher incidence (1.8 vs. 0.6%, p < 0.001) and cumulative incidence (log-rank test, p < 0.001) of hospital-associated GU infection. The Cox's models confirmed these findings (hazard ratio: >2.82, confidence interval: 1.63-4.87 in composite models).

CONCLUSION

iSUA represents an independent risk factor for GU infection. Urinary tract imaging may be warranted.

Ambient air pollution and the risk of stillbirth: a population-based prospective birth cohort study in the coastal area of China

Accumulating evidence has shown that prenatal ambient air pollution exposure is associated with elevated stillbirth risk; however, the results are inconsistent. This population-based prospective cohort study aimed to explore the association between prenatal air pollution exposure and stillbirth rate in the coastal area in China. Data of air pollution and birth outcomes between January 1, 2015, and December 31, 2017, were collected. Among the 59,868 eligible births, there were 587 stillbirths and 59,281 live births. Although the air quality in this study was relatively better than most of the major cities in China, a positive association was still found between prenatal air pollution exposure and stillbirth rate. Every 10 μg/m³ increase of fine particulate matters (PM_2.5) in each trimester, as well as in the entire pregnancy, was associated with increased stillbirth rate (RR = 1.14, 1.11, 1.15, and 1.14 for the first, second, third trimester, and entire pregnancy, respectively). In addition, every 10 μg/m³ increase of PM₁₀ in the first trimester (RR = 1.09, 95% CI: 1.04-1.14), and 10 μg/m³ increase of O₃ in the first (RR = 1.05, 95% CI: 1.01-1.09) and third (RR = 1.04, 95% CI: 1.00-1.08) trimesters was also associated with increased stillbirth rate. The effects of PM_2.5 on stillbirth rate were found to be robust in the two-pollutant models. The findings of this study especially underscored the adverse effects of prenatal exposure of high levels of PM_2.5 on stillbirth. More studies are needed to verify our findings and further investigate the underlying mechanisms.

ROS-AKT-mTOR axis mediates autophagy of human umbilical vein endothelial cells induced by cooking oil fumes-derived fine particulate matters in vitro

Cooking oil fumes-derived PM_2.5 (COFs-derived PM_2.5) exposure can induce oxidative stress and cytotoxic effects. Here we investigated the role of ROS-AKT-mTOR axis in COFs-derived PM_2.5-induced autophagy in human umbilical vein endothelial cells (HUVECs). HUVECs were treated with different concentrations of COFs-derived PM_2.5, together with or without N-acetyl-L-cysteine (NAC, a radical scavenger) or 3-methyladenine (3-MA, an autophagy inhibitor). Cell viability was assessed with MTT assay, and ROS level was measured with DCFH-DA assay after the treatment. Transmission electron microscopy (TEM) was used to evaluate the formation of autophagosomes, while immunofluorescent assay and western blot were used to assess the expression of LC3-I/II and beclin 1. Proteins involved in the PI3K-AKT-mTOR signaling pathway were measured with western blot. The results showed that the treatment of COFs-derived PM_2.5 dose-dependently reduced the viability of HUVECs and increased the ROS levels in the cells. Both immunofluorescent assay and western blot showed that treatment with COFs-derived PM_2.5 significantly increased LC3-II and beclin 1 levels, as well as the ratio of LC3-II/LC3-I, which could be rescued by the co-incubation with NAC or 3-MA. TEM also confirmed the increased formation of autophagosomes in the cells treated with COFs-derived PM_2.5, while co-treatment with NAC evidently decreased autophagosomes formation. In addition, western blot also showed that the phosphorylation of PI3K, AKT, and mTOR all decreased by the treatment of COFs-derived PM_2.5, which was effectively rescued by the co-treatment with NAC. These findings demonstrate ROS-AKT-mTOR axis plays a critical role in HUVECs autophagy induced by COFs-derived PM_2.5.

Placental abnormalities associated with isolated single umbilical artery in small-for-gestational-age births

BACKGROUND

Previous studies have shown that pregnancies complicated by placentas with an isolated single umbilical artery (iSUA) are at increased risk for small-for-gestational-age (SGA) births. The etiology of SGA in this population, however, remains unknown.

OBJECTIVE

The primary objective of this study was to evaluate whether placental abnormalities in pregnancies with SGA births differ according to the presence of iSUA.

STUDY DESIGN

This was an observational study of all women with pathologic examination of the placenta after delivering a non-anomalous, singleton SGA neonate between January 2009 and August 2015. SGA was defined as birthweight less than 10th percentile for gestational age. Women were categorized according to whether they had an iSUA or a three-vessel cord. The following placental pathologies were compared between the groups using bivariable and multivariable analyses: SGA placenta, maternal vascular malperfusion, high grade fetal vascular malperfusion, and chronic villitis.

RESULTS

1833 women were included in the analysis: 34 with iSUA and 1799 with three-vessel cord. More than 85% of women in both groups had at least one placental abnormality. After adjusting for nulliparity and neonatal gender, the presence of iSUA was associated with increased odds of high grade fetal vascular malperfusion (adjusted odds ratio 2.8, 95% confidence interval 1.1-7.5) and decreased odds of maternal vascular malperfusion (adjusted odds ratio 0.2, 95% confidence interval 0.1-0.9). There was no significant association with other pathologic findings.

CONCLUSION

Pathologic placental findings associated with SGA birth differed based on umbilical cord composition. The presence of iSUA in an SGA birth was associated with a higher odds of high grade fetal vascular malperfusion abnormalities and lower odds of maternal vascular malperfusion abnormalities, compared to SGA birth with a 3VC.