Umbilical artery half peak systolic velocity deceleration time throughout pregnancy and its role in fetuses with bradycardia

Umbilical artery half peak systolic velocity deceleration time: a novel Doppler parameter for prediction of neonatal outcomes in pregnant women with preeclampsia

PURPOSE

To assess the effectiveness of half peak systolic velocity deceleration time (hPSV-DT) in predicting neonatal outcomes in pregnant women with preeclampsia and to compare its usefulness with the conventional umbilical artery (UA) pulsatility index (PI) approach.

METHODS

A prospective cohort study was conducted among pregnant women with preeclampsia who were admitted to the Department of Perinatology, Ministry of Health Ankara City Hospital between 01 September 2022 and 01 January 2023 at 28-41 weeks gestational age. 55 patients were divided into two groups: the study group with UA hPSV-DT value < 5th percentile (n = 22) and the control group with UA hPSV-DT value ≥ 5th percentile (n = 33). UA hPSV-DT calculates the time in milliseconds needed to halve the maximal velocity of the UA waveform using Doppler ultrasonography.

RESULTS

Birth weight, gestational age at birth, 1st minute APGAR, 5th minute APGAR, and umbilical cord pH values were significantly lower in the anormal hPSV-DT group (p < 0.05). Additionally, the rates of admission to NICU, respiratory distress syndrome (RDS), delivery time < 34 weeks, and birth weight < 2500 g were significantly more frequent in the anormal hPSV-DT group compared to the normal hPSV-DT group (p < 0.05). UA-PI > 95th percentile was detected in only 2 (8%) of 23 patients whose newborns were admitted to the NICU (p = 0.149), while hPSV-DT < 5th percentile was detected in 16 (69%) of 23 patients (p < 0.001). According to ROC analysis, the area under the curve was 0.82 (95% CI 0.06-0.28) for admission to the NICU. The best balance of sensitivity/specificity in ROC curves was 221.5 (82.6% sensitivity, 69.1% specificity, p < 0.001).

CONCLUSION

UA hPSV-DT was successful in predicting composite adverse perinatal outcomes in pregnant women with preeclampsia. It is a promising novel method that is accurate, quantitative, reproducible, and easily applicable. With further studies, this method may be a primary diagnostic tool in the management of high-risk pregnancies and in determining the optimal timing of delivery.

Echocardiographic and ultrasound evaluation of haemodynamic parameters in hypoxic neonates treated with hypothermia: Study protocol

Background

Episodes of ischaemia-hypoxia in the perinatal period as well as the changes in the redistribution of blood may lead to decreased perfusion and ischaemia of the cardiac muscle. Additionally, there is a negative impact from the reduced contractility of the cardiac muscle secondary to acidosis and hypoxia. Therapeutic hypothermia (TH) improves the late effects in moderate and severe cases of hypoxia-ischaemia encephalopathy (HIE). The direct impact of TH on the cardiovascular system includes moderate bradycardia, increased pulmonary vascular resistance (PVR), inferior filling of the left ventricle (LV) and LV stroke volume. The above-mentioned consequences of TH and episodes of HI in the perinatal period are therefore exacerbation of respiratory and circulatory failure. The impact of the warming phase on the cardiovascular system is not well researched and currently few data has been published on this topic. Physiologically, warming increases heart rate, improves cardiac output and increases systemic pressure. The effect of TH and the warming phase on the cardiovascular values has a decisive impact on the metabolism of drugs, including vasopressors/inotropics, which in turn affects the choice of medication and fluid therapy.

Method

The study is a multi-centre, prospective, case-control, observational study. The study will include 100 neonates (50 subjects and 50 controls). Echocardiography and cerebral and abdominal ultrasound will be performed in the first 1/2 days after birth as well as during warming i.e., on day 4/7 of life. In neonatal controls these examinations will be performed for indications other than hypothermia, most frequently because of poor adaptation.

Ethics and dissemination

The Ethics Committee of the Medical University of Warsaw approved the study protocol prior to recruitment (KB 55/2021). Informed consent will be obtained from the carers of the neonates at the time of enrolment. Consent for participation in the study can be withdrawn at any time, without consequences and without obligation to justify the decision. All data will be stored in a secure, password-protected Excel file that is only accessible to researchers involved in the study. Findings will be published in a peer-reviewed journal and disseminated at relevant national and international conferences.

Clinical Trial Registration

NCT05574855.

Umbilical artery pulsatility index and half-peak systolic velocity in second- and third-trimester fetuses with trisomy 18 and 13

OBJECTIVES

To analyze umbilical artery (UA) Doppler velocimetry and its possible role in placenta-mediated fetal growth restriction (FGR) in second- and third-trimester fetuses with trisomy 18 and 13.

METHODS

UA pulsatility index (PI) and half-peak systolic velocity deceleration time (hPSV-DT) were measured in fetuses with trisomy 18 and 13. Correlation with gestational age, birthweight, and perinatal outcome was analyzed.

RESULTS

A total of 80 measurements were taken from 33 fetuses with trisomy 18 and 19 with trisomy 13. Overall, there was a high prevalence of abnormal UA Doppler velocimetry. In fetuses with trisomy 18, 54% (27/50) of the UA PI values and 58% (29/50) of the UA hPSV-DT values were abnormal. In fetuses with trisomy 13, 80% (24/30) of the UA PI values and 87% (26/30) of the UA hPSV-DT values were abnormal. The prevalence of abnormal UA Doppler velocimetry increased with gestational age in both types of aneuploidy. However, this trend was only significant for trisomy 13 (p<0.05). All fetuses with trisomy 18 and 86% of fetuses with trisomy 13 were classified at birth as FGR. There were no perinatal survivors in this series.

CONCLUSIONS

A high prevalence of abnormal UA Doppler velocimetry was found in second- and third-trimester fetuses with trisomy 18 and 13, which further increased with gestational age. These results may well correlate with alterations described previously in the placenta, suggesting placental insufficiency has an important role in the development of FGR in these autosomal aneuploid fetuses.

Umbilical artery pulsatility index and half-peak systolic velocity deceleration time in fetuses with trisomy 21

Objective: To analyze placental vascular resistance and the role of placental insufficiency in the etiology of reduced fetal growth in fetuses with trisomy 21 as determined by umbilical artery (UA) Doppler velocimetry.Methods: Second- and third-trimester UA Doppler ultrasound studies were performed in fetuses with trisomy 21 at the time of clinically indicated obstetric ultrasound assessment. The UA pulsatility index (PI) and half-peak systolic velocity deceleration time (hPSV-DT) were measured and recorded. Perinatal outcome was reviewed and the results from UA Doppler velocimetry were compared with birthweight according to gestational age at the time of the delivery.Results: A total of 60 fetuses with trisomy 21 were studied and information from 147 UA Doppler studies was analyzed. Overall, at least one of the UA PI and hPSV-DT values was abnormal in 82% (n = 49) and 90% (n = 54) of the cases, respectively. The incidence of abnormal UA PI values increased with gestational age from 39% (7/18) before 21 weeks to 78% (18/23) after 35 weeks (p < .05). The increase was even more evident for UA hPSV-DT values from 28% (5/18) before 20 weeks to 91% (21/23) after 35 weeks (p < .01). After exclusion of four fetuses with hydrops or isolated hydrothorax/ascites, 16 (29%) were classified at birth as small for gestational age (SGA), 34 (61%) as adequate for gestational age, and six (11%) as large for gestational age, with a mean birthweight z-score of -0.36. When only considering the last Doppler ultrasound assessment prior to delivery, UA PI and hPSV-DT values were abnormal in 73% (41/56, mean z-score = +1.72) and 82% (46/56; mean z-score = -2.18) of the cases, respectively. Mean gestational age at delivery and birth weight were significantly lower in the group with abnormal compared to normal UA PI and hPSV-DT values. Similarly, the incidence of SGA fetuses was significantly higher in the group with abnormal compared to normal UA PI and hPSV-DT values, with 94 (n = 15) and 100% of the 16 SGA newborn infants having abnormal UA PI and hPSV-DT values prior to delivery, respectively.Conclusions: Trisomy 21 fetuses have a progressively higher incidence of abnormal UA impedance indices throughout pregnancy, which suggests developing placental vascular resistance as the pregnancy progresses. This alteration likely begins around the mid second trimester and increases with gestational age; however, increasing placental vascular resistance seems to produce a discrete decrease in fetal growth, despite severe alteration of the UA Doppler impedance indices. As a general hypothesis, we postulate that trisomy 21 fetuses have increasing placental vascular resistance but there may be some factors that protect these fetuses from severe fetal growth restriction.

Umbilical Artery Half-Peak Systolic Velocity Deceleration Time in Fetal Growth Restriction

Objective: To study the umbilical artery (UA) half-peak systolic velocity deceleration time (hPSV-DT) in pregnancies complicated by fetal growth restriction (FGR). Methods: The study included 266 singleton, high-risk pregnancies with an estimated fetal weight <10th percentile, which were examined between 24 and 40 weeks' gestation and delivered within a week from the last ultrasound evaluation. UA hPSV-DT was measured with Doppler ultrasound in the same wave used to measure the pulsatility index. UA hPSV-DT values were correlated with perinatal outcome. Results: UA hPSV-DT <5th percentile was found in 87 and 98% of fetuses with moderate and severe FGR, respectively. 94% of fetuses with a UA hPSV-DT <90 ms had poor perinatal outcome including perinatal death or prolonged admission to the neonatal intensive care unit. None of the fetuses had a UA hPSV-DT <70 ms. Perinatal death occurred in 39 fetuses; UA hPSV-DT was abnormal in all of them, with 95% of these fetuses having values of ≤120 ms. In the group of fetuses with absent/reverse end-diastolic velocity in the UA, the perinatal mortality rate was 51% for those with a UA hPSV-DT ≤90 ms and only 23% for those having a UA hPSV-DT >90 ms (p < 0.01). Conclusions: UA hPSV-DT seems to be a useful technique in the evaluation of pregnancies at risk for FGR and perinatal death. Additionally, hPSV-DT was shown to be a good predictor of perinatal death, with values of <90 ms corresponding to imminent risk of intrauterine demise and values of <70 ms being likely to be incompatible with intrauterine life.