The Effects of Absent or Reversed End-diastolic Umbilical Artery Doppler Flow Velocity

Rate of deterioration of umbilical artery Doppler indices in fetuses with severe early-onset fetal growth restriction

BACKGROUND

Incorporation of umbilical artery Doppler in the surveillance of fetal growth restriction has been shown to reduce the risk of perinatal deaths. Systole/Diastole ratio, Pulsatility Index and Resistance Index are obtained upon Doppler interrogation of the umbilical artery however it is unknown which index predicts more advanced stages of placental deterioration.

OBJECTIVE

This study aimed to examine risk factors for the development of absent or reversed end-diastolic velocity and the time intervals of deterioration from normal umbilical artery end-diastolic velocity (indicated by systole/diastole ratio, pulsatility index, or resistance index) to decreased and absent or reversed end-diastolic velocity in fetuses with early-onset severe fetal growth restriction.

STUDY DESIGN

This was a retrospective cohort study performed from 2005 to 2020. All singleton pregnancies with severe (estimated fetal weight or abdominal circumference below the third percentile) and early-onset (diagnosed between 20 0/7 and 31 6/7 weeks of gestation) fetal growth restriction were included. Patients with fetal genetic or structural anomalies, suspected congenital infections, absent or reversed end-diastolic velocity at diagnosis, poor pregnancy dating, and absence of follow-up ultrasounds were excluded. Estimated fetal weight, abdominal circumference, and Doppler indices were reviewed longitudinally from diagnosis to delivery. To examine risk factors for absent or reversed end-diastolic velocity, we performed backward stepwise logistic regression and calculated odds ratios with 95% confidence intervals. Kaplan-Meier curves were compared using log-rank tests.

RESULTS

A total of 985 patients met the inclusion criteria, and 79 (8%) progressed to absent or reversed end-diastolic velocity. Factors associated with development of absent or reversed end-diastolic velocity included gestational age at diagnosis (adjusted odds ratio, 4.88 [95% confidence interval, 2.55-9.37] at 20 0/7 to 23 6/7 weeks; adjusted odds ratio, 1.56 [95% confidence interval, 0.86-2.82] at 24 0/7 to 27 6/7 weeks compared with 28 0/7 to 31 6/7 weeks) and presence of chronic hypertension (adjusted odds ratio, 2.37 [95% confidence interval, 1.33-4.23]). Rates of progression from diagnosis of fetal growth restriction with normal umbilical artery Doppler to absent or reversed end-diastolic velocity were significant after 4 weeks from diagnosis (5.84% [95% confidence interval, 4.50-7.57]). Regarding the Doppler indices, the progression from normal values to abnormal indices was similar at 1 and 2 weeks. However, the rate of progression from normal to abnormal systole/diastole ratio compared with the rates of progression from normal to abnormal pulsatility index or resistance index was higher at 4 and 6 weeks. Deterioration from abnormal indices to absent or reversed end-diastolic velocity was shorter with abnormal resistance index and pulsatility index when compared with the systole/diastole ratio at 2, 4, and 6 weeks after diagnosis and at 6 weeks, respectively.

CONCLUSION

Earlier gestational age at diagnosis and chronic hypertension are considered as risk factors for Doppler deterioration and development of absent or reversed end-diastolic velocity in the umbilical artery. With normal Doppler indices, significant deterioration and progression to absent or reversed end-diastolic velocity is unlikely until 4 weeks after diagnosis. Abnormal systole/diastole ratio seems to appear first. However, abnormal pulsatility index or resistance index was associated with absent or reversed end-diastolic velocity.

Necrotizing Enterocolitis: The Role of Hypoxia, Gut Microbiome, and Microbial Metabolites

Necrotizing enterocolitis (NEC) is a life-threatening disease that predominantly affects very low birth weight preterm infants. Development of NEC in preterm infants is accompanied by high mortality. Surgical treatment of NEC can be complicated by short bowel syndrome, intestinal failure, parenteral nutrition-associated liver disease, and neurodevelopmental delay. Issues surrounding pathogenesis, prevention, and treatment of NEC remain unclear. This review summarizes data on prenatal risk factors for NEC, the role of pre-eclampsia, and intrauterine growth retardation in the pathogenesis of NEC. The role of hypoxia in NEC is discussed. Recent data on the role of the intestinal microbiome in the development of NEC, and features of the metabolome that can serve as potential biomarkers, are presented. The Pseudomonadota phylum is known to be associated with NEC in preterm neonates, and the role of other bacteria and their metabolites in NEC pathogenesis is also discussed. The most promising approaches for preventing and treating NEC are summarized.

Insights into Prevention of Health Complications in Small for Gestational Age (SGA) Births in Relation to Maternal Characteristics: A Narrative Review

Small for gestational age (SGA) births are a significant clinical and public health issue. The objective of this review was to summarize maternal biological and socio-demographic factors and preventive strategies used to reduce the risk of SGA births. A literature search encompassing data from the last 15 years was conducted using electronic databases MEDLINE/PubMed, Google Scholar and Scopus to review risk factors and preventive strategies for SGA. Current evidence shows that primiparity, previous stillbirths, maternal age ≤24 and ≥35 years, single motherhood, low socio-economic status, smoking and cannabis use during pregnancy confer a significant risk of SGA births. Studies on alcohol consumption during pregnancy and SGA birth weight are inconclusive. Beneficial and preventive factors include the "Mediterranean diet" and dietary intake of vegetables. Periconceptional folic acid supplementation, maternal 25-hydroxyvitamin D, zinc and iron levels are partly associated with birth weight. No significant associations between COVID-19 vaccinations and birthweight are reported. A midwifery-led model based on early and extensive prenatal care reduces the risk of SGA births in women with low socio-economic status. Major preventive measures relate to the awareness of modifiable and non-modifiable risk factors of SGA, leading to changes in parents' lifestyles. These data support that education, monitoring during pregnancy, and implementing preventive strategies are as important as biological determinants in risk reduction of SGA births.

Comparative study of the umbilical artery Doppler indices of healthy and growth-restricted foetuses in Lagos

Aim of the Study:

This study compared the umbilical artery Doppler indices (UADI) in normal and foetal growth-restricted (FGR) foetuses to determine the relationship between the UADI and pregnancy outcomes.

Materials and Methods:

This was a case-control study that recruited one hundred and eighty pregnant women comprising 90 with FGR pregnancies and 90 with normal pregnancies. Foetal biometric parameters and UADI were measured in all the participants. The UADI and clinical outcomes (preterm delivery, birth weight, perinatal death, etc.) of the normal and FGR foetuses were compared.

Results:

The mean estimated foetal weights of the FGR pregnancies (subjects) and normal pregnancies (controls) were 2.76 ± 0.66 kg and 3.62 ± 0.37 kg, respectively (P < 0.0001). The mean APGAR score at 5 min was 6.93 ± 1.72 for subjects and 8.03 ± 0.94 for controls (P < 0.0001). Abnormal umbilical artery Doppler waveforms were detected: decreased end-diastolic flow in 25 (27.8%), absent end-diastolic in 7 (7.8%) and reversed end-diastolic flow in 4 (4.4%) of the FGR pregnancies. There were 74 (82.2%) preterm deliveries among the subjects, while only 7 (7.8%) of the controls had preterm deliveries. Six deaths (two perinatal and four neonatal deaths) were recorded among the subjects, while no death occurred among the controls.

Conclusion:

Foetuses with FGR showed significantly higher quantitative Doppler indices (increased RI, PI, SD ratio), and a higher prevalence of abnormal umbilical artery waveform pattern (qualitative) than the healthy foetuses (controls).

Acute ambient air pollution exposure and placental Doppler results in the NICHD fetal growth studies - Singleton cohort

BACKGROUND

Increased placental vascular resistance is a proposed mechanism by which air pollution exposure during pregnancy lowers birth weight and increases pregnancy-induced hypertensive disorders.

OBJECTIVE

To examine the impact of acute air pollution exposure during pregnancy on uterine and umbilical artery Doppler indicators of placental vascular resistance.

METHODS

After a first ultrasound to confirm gestational age, 2562 pregnant women recruited in 12 clinics throughout the United States underwent up to five standardized ultrasounds with Doppler measurements. Exposures to 11 air pollutants were estimated for the hour of ultrasound and each of the 2 h prior to ultrasound at the clinics using the National Air Quality Forecast Capability reanalysis products. We used mixed logistic regression to study the longitudinal odds ratio (OR) of any, uni- or bi-lateral systolic and diastolic uterine artery notching compared to no notching and the longitudinal OR of abnormal end diastolic flow of the umbilical artery compared to forward flow. Uterine and umbilical artery resistance indexes were studied using linear mixed models.

RESULTS

Each inter-quartile range (IQR) increase of particulate matter < 2.5 μm, nitrate, ammonium, primary organic matter (POM) and nitrogen dioxide during the hour of ultrasound was associated with a decreased risk of unilateral systolic notch and with increased resistance index of the left uterine artery. For the umbilical artery, each IQR increase in ozone was associated with decreased resistance index (b: -0.26, 95 % CI: -0.52, -0.01) and with a decreased risk of abnormal end diastolic flow (OR: 0.36, 95 % CI: 0.14, 0.94); while each IQR increase of elemental carbon and POM was associated with increased risk of abnormal end diastolic flow (OR: 1.47, 95 % CI: 1.02, 2.13 and OR: 1.67, 95 % CI: 1.17, 2.39, respectively).

DISCUSSION

Our results suggest acute air pollution exposure may influence placental vascular resistance.

Two novel presentations of KCNMA1-related pathology--Expanding the clinical phenotype of a rare channelopathy

BACKGROUND

KCNMA1 mutations have recently been associated with a wide range of dysmorphological, gastro-intestinal, cardiovascular, and neurological manifestations.

METHODS

Whole exome sequencing was performed in order to identify the underlying pathogenic mutation in two cases presenting with diverse phenotypical manifestations that did not fit into well-known clinical entities.

RESULTS

In an 8-year-old boy presenting with severe aortic dilatation, facial dysmorphism, and overgrowth at birth a de novo p.Gly375Arg KCNMA1 mutation was identified which has been reported previously in association with gingival hypertrophy, aortic dilatation, and developmental delay. Additionally, in a 30-week-old fetus with severe growth retardation and duodenal atresia a de novo p.Pro805Leu KCNMA1 mutation was identified. The latter has also been reported before in a boy with severe neurological manifestations, including speech delay, developmental delay, and cerebellar dysfunction.

CONCLUSION

The current report presents the first antenatal presentation of a pathogenic KCNMA1 mutation and confirms the specific association of the p.Gly375Arg variant with early onset aortic root dilatation, gingival hypertrophy, and neonatal overgrowth.

Multiscale and multimodal imaging of utero-placental anatomy and function in pregnancy

Placental structures at the nano-, micro-, and macro scale each play important roles in contributing to its function. As such, quantifying the dynamic way in which placental structure evolves during pregnancy is critical to both clinical diagnosis of pregnancy disorders, and mechanistic understanding of their pathophysiology. Imaging the placenta, both exvivo and invivo, can provide a wealth of structural and/or functional information. This review outlines how imaging across modalities and spatial scales can ultimately come together to improve our understanding of normal and pathological pregnancies. We discuss how imaging technologies are evolving to provide new insights into placental physiology across disciplines, and how advanced computational algorithms can be used alongside state-of-the-art imaging to obtain a holistic view of placental structure and its associated functions to improve our understanding of placental function in health and disease.

Clinical monitoring of late fetal growth restriction

Late fetal growth restriction (FGR) poses its own challenges in respect of diagnosis, surveillance and delivery timing. Perinatal morbidity is relatively rare, and mortality extremely unusual, but given that late FGR is much more frequent than early FGR, the burden on neonatal services must not be underestimated. Doppler findings are more subtle than in early FGR, and growth rate rather than absolute fetal size may be important in defining the condition. Though umbilical artery Doppler changes form the basis for triggering delivery: reversed end diastolic flow at 32 weeks, absent at 34 weeks and raised PI at 36 weeks, other modalities of monitoring - for example cardiotocography and cerebral Doppler - are important in surveillance and timing follow up of the condition.

Abnormal Umblical Artery Doppler is Utilized for Fetuses with Intrauterine Growth Restriction Birth at 280/7-336/7 Gestational Weeks

Purpose: To compare short-term perinatal outcomes in preterm infants with intrauterine growth restriction (IUGR) in those with absent or reversed end-diastolic umbilical artery blood flow (AREDF) to those with normal end-diastolic umbilical artery blood flow (NEDF). Methods: This study included preterm births (28^0/7-33^6/7 gestational weeks) with IUGR with AREDF (n = 86) or NEDF (n = 27). Results: There were lower mean gestational weeks, birth weights, and a higher ratio of corticosteroid application in the AREDF group (p < 0.05). The mean length of neonatal intensive care unit stay of the AREDF group was significantly longer (p < 0.001). Sepsis and feeding intolerance ratios in the AREDF group were also significantly higher (p = 0.041 and p < 0.001 respectively). Conclusions: Patients with IUGR and umbilical Doppler abnormalities have longer neonatal intensive care unit stays.

The impact of intrauterine growth restriction on respiratory outcomes

BACKGROUND

Intrauterine growth restriction (IUGR) is caused by fetal growth below what is normal for its genetic potential. Recent studies have shown a distinct association between changes in umbilical artery flow in IUGR subjects and an increased risk of respiratory morbidity and consequently, higher mortality. The aim of this study was to find the impact of IUGR on the respiratory outcomes of premature neonates born with less than 32 weeks gestational age.

METHODS

This retrospective cohort study targeted infants born with less than 32 weeks of gestation, admitted at NCIU, between January 2010 and December 2016. Each selected IUGR case was matched according to gestational age and sex with an appropriate birthweight newborn at a 1:2 ratio, within a 12-month period.

RESULTS

The study involved 126 neonates, 42 with IUGR, and 84 control subjects. IUGR was not identified as a predictor of Bronchopulmonary Dysplasia (BDP) (OR 4.80, 95% CI: 1.14-20.21, P=0.033). Abnormal umbilical artery flow (OR 4.80, 95% CI: 1.14-20.21, P=0.033) and late onset sepsis (OR 3.31, 95% CI: 1.04-10.56, P=0.044) were significantly associated with BDP.

CONCLUSIONS

It is essential to recognize changes in the umbilical artery flow, especially in high-risk pregnancies such as IUGR, since these represent an a priori risk marker for the development of BDP. The individual and combined effect of IUGR, alterations on umbilical artery flow and extreme prematurity has not yet been completely clarified on the impact on lung morbidity, requiring a larger number of studies.

Neurodevelopmental outcome in very low birthweight infants with pathological umbilical artery flow

OBJECTIVE

To assess neurodevelopmental outcome during toddlerhood in very low birthweight (VLBW) infants with absent or reverse end-diastolic flow (AREDF) in the umbilical artery (UA) during pregnancy.

DESIGN

Retrospective cohort study with matched control group.

SETTING

Tertiary perinatal centre.

PATIENTS AND OUTCOME MEASURES

We compared longitudinally collected data on neonatal and neurodevelopmental outcomes among 41 infants born in our institution from 1997 to 2010 with birth weight <1500 g and UA AREDF and 41 infants with prenatally normal UA Doppler parameters matched for gestational age, birth weight, sex and year of birth. We evaluated neurodevelopmental outcome at a median (range) corrected age of 23.3 (10.1-29.6) months using the Bayley scales of infant development, 2nd edition (BSID-II), and neurological examination.

RESULTS

The mental development index in UA AREDF children (median (range) 84 (49-116)) was significantly lower than in controls (median (range) 91 (62-140)), including after adjustment for confounders. Intergroup differences in psychomotor development index (PDI; BSID-II) and the rate of cerebral palsy or minor neuromotor dysfunction were non-significant.

CONCLUSIONS

VLBW infants with UA AREDF have a higher risk of poorer mental development during toddlerhood than controls matched for gestational age, birth weight, sex and year of birth. UA AREDF may be considered a prenatal predictor of poorer mental development in this population. Long-term follow-up studies with larger cohorts are needed to better evaluate the impact of this prenatal factor on later neurodevelopment.

Does low-molecular-weight heparin influence fetal growth or uterine and umbilical arterial Doppler in women with a history of early-onset uteroplacental insufficiency and an inheritable thrombophilia? Secondary randomised controlled trial results

OBJECTIVE

Does low-molecular-weight heparin (LMWH) added to low-dose aspirin influence fetal growth and flow velocity in uterine and umbilical arteries in women with an inheritable thrombophilia and previous early-onset uteroplacental insufficiency?

DESIGN

Secondary outcomes of the FRUIT-RCT.

SETTING

Multicentre, international.

POPULATION

The FRUIT-RCT included 139 women with inheritable thrombophilia before 12 weeks of gestation. Inclusion criteria were previous delivery before 34 weeks of gestation with a hypertensive disorder of pregnancy and/or small-for-gestational-age infant and an inheritable thrombophilia.

METHODS

After randomisation to either daily LMWH with aspirin, or aspirin only, ultrasound measurements were performed at 22-24, 28-30 and 34-36 weeks of gestation. Development during gestation of growth, birthweight and flow velocity of the umbilical artery was examined using the linear mixed model. Uterine artery flow velocity at a single time-point (22-24 weeks) was examined using a chi-square test.

MAIN OUTCOME MEASURES

Fetal growth over time including birthweight, using Scandinavian, Dutch and customised growth curves; and flow velocity within the uterine and umbilical arteries.

RESULTS

No difference of fetal growth over time could be demonstrated between the study arms, regardless of which reference criteria were used. The flow velocity within the uterine artery and umbilical artery did not differ between study arms.

CONCLUSION

The addition of LMWH to aspirin did not influence fetal growth or umbilical artery flow velocity over time; nor did it influence uterine artery flow velocity.

TWEETABLE ABSTRACT

LMWH does not influence fetal growth or uterine or umbilical flow velocities.

Sepsis and pregnancy: do we know how to treat this situation?

Sepsis is defined as an acute inflammatory response syndrome secondary to an infectious focus. It has a high incidence, morbidity and mortality, causing substantial financial costs, especially due to complications such as septic shock and multiple organ dysfunction. The pathogen toxins associated with individual susceptibility culminate with cytokine release, which promotes a systemic inflammatory response that can progress to multiple organ dysfunction and eventual patient death.

Specifically, sepsis incidence, morbidity and mortality are lower in pregnant women, as this group is typically younger with fewer comorbidities having a polymicrobial etiology resulting in sepsis.

Pregnant women exhibit physiological characteristics that may confer specific clinical presentation and laboratory patterns during the sepsis course. Thus, a better understanding of these changes is critical for better identification and management of these patients. The presence of a fetus also requires unique approaches in a pregnant woman with sepsis.

Sepsis treatment is based on certain guidelines that were established after major clinical trials, which, unfortunately, all classified pregnancy as a exclusion criteria.

Thus, the treatment of sepsis in the general population has been extrapolated to the pregnant population, with the following main goals: maintenance of tissue perfusion with fluid replacement and vasoactive drugs (initial resuscitation), adequate oxygenation, control of the infection source and an early start of antibiotic therapy, corticosteroid infusion and blood transfusion when properly indicated, prophylaxis, and specifically monitoring and maintenance of fetal heath.

Maternal preeclampsia is associated with increased risk of necrotizing enterocolitis in preterm infants

BACKGROUND

Necrotizing enterocolitis (NEC) is an important cause of mortality and morbidity in preterm infants.

AIMS

To evaluate the effect of maternal preeclampsia on the development and severity of NEC in premature infants.

STUDY DESIGN

Prospective observational study in a tertiary neonatal intensive care unit.

SUBJECTS

The preterm infants of ≤ 37 gestational age who were consecutively hospitalized were enrolled. The study group contained preterm infants born to a preeclamptic mother and the comparison group contained preterm infants born to a normotensive mother.

OUTCOME MEASURES

The primary outcome was to determine the association between preeclampsia and NEC.

RESULTS

A total of 88 infants had NEC diagnosis. The incidence of NEC in infants born to preeclamptic mothers (22.9%) was significantly higher compared with those born to normotensive mothers (14.6%). According to NEC stages, NEC was more advanced in preeclamptic mother infants. NEC developed significantly earlier in infants with NEC in the study group. The duration of NEC was also significantly longer in infants born to preeclamptic mothers. In multiple logistic regression model, preeclampsia was found to be predictive of NEC with an odds ratio of 1.74 (95% confidence interval 0.64-0.92).

CONCLUSIONS

Maternal preeclampsia may be an important risk factor for the development of NEC in premature infants as NEC incidence and severity of NEC were found to be significantly higher in premature infants born to preeclamptic mothers. The onset of NEC was significantly earlier and duration of NEC was longer in these infants.