Umbilical Flow Research Articles

VP41.09: Value of umbilical vein flow as a predictor of wellbeing in small‐for‐gestational‐age fetuses

VP41.09: Value of umbilical vein flow as a predictor of wellbeing in small‐for‐gestational‐age fetuses

VP40.04: Does umbilical vein blood flow assessment improve the prediction of fetal macrosomia at 36 weeks of gestation?

VP40.04: Does umbilical vein blood flow assessment improve the prediction of fetal macrosomia at 36 weeks of gestation?

Mid-gestational fetal placental blood flow is diminished in the fetus with congenital heart disease.

Data suggest fetuses with congenital heart disease (CHD) have placental abnormalities. Their abnormal placental vasculature may affect fetal placental blood flow, which has not previously been explored. We performed a retrospective cross-sectional study comparing umbilical venous volume flow (UVVF) of single ventricle, D-transposition of the great arteries, and tetralogy of Fallot fetuses with fetuses without CHD. UVVF and combined cardiac output (CCO) were calculated from fetal echocardiography and compared using t tests, χ2 and Fisher's exact tests. Mean gestational age and fetal weight were greater in CHD fetuses (26.5 weeks, 1119.4 g; n = 81, P < .001) compared to controls (23.1 weeks, 675 g; n = 170, P < .001). UVVF/fetal weight was nevertheless decreased among cases (99.8 vs 115.3 mL/min/kg, P < .001). Subgroup analysis of 20- to 25-week fetuses demonstrated no significant differences in case and control baseline characteristics. In CHD fetuses (n = 31) compared to controls (n = 144), absolute UVVF (50.8 vs 62.1 mL/min, P = .006), and UVVF/fetal weight (98.8 vs 118.5 mL/min/kg, P < .001) were decreased. Findings were similar in single ventricle (n = 24) and hypoplastic left heart syndrome (n = 14). Mid-gestational placental blood flow in CHD fetuses is decreased compared to controls. Further study is needed to explore the relationship between UVVF and placental pathology, and impact on outcomes.

Comparison of Variations Between Spectral Doppler and Gaussian Surface Integration Methods for Umbilical Vein Blood Volume Flow.

We are studying a new method for estimating blood volume flow that uses 3-dimensional ultrasound to measure the total integrated flux through an ultrasound-generated Gaussian surface that intersects the umbilical cord. This method makes none of the assumptions typically required with standard 1-dimensional spectral Doppler volume flow estimates. We compared the variations in volume flow estimates between techniques in the umbilical vein. The study was Institutional Review Board approved, and all 12 patients gave informed consent. Because we had no reference standard for the true umbilical vein volume flow, we compared the variations of the measurements for the flow measurement techniques. At least 3 separate spectral Doppler and 3 separate Gaussian surface measurements were made along the umbilical vein. Means, standard deviations, and coefficients of variation (standard deviation/mean) for the flow estimation techniques were calculated for each patient. P < .05 was considered significant. The ranges of the mean volume flow estimates were 174 to 577 mL/min for the spectral Doppler method and 100 to 341 mL/min for the Gaussian surface integration (GSI) method. The mean standard deviations (mean ± SD) were 161 ± 95 and 45 ± 48 mL/min for the spectral Doppler and GSI methods, respectively (P < .003). The mean coefficients of variation were 0.46 ± 0.17 and 0.18 ± 0.14 for the spectral Doppler and GSI methods respectively (P < 0.002). The new volume flow estimation method using 3-dimensional ultrasound appears to have significantly less variation in estimates than the standard 1-dimensional spectral Doppler method.

Cardiopulmonary Resuscitation of Asystolic Newborn Lambs Prior to Umbilical Cord Clamping; the Timing of Cord Clamping Matters!

Background: Current guidelines recommend immediate umbilical cord clamping (UCC) for newborns requiring chest compressions (CCs). Physiological-based cord clamping (PBCC), defined as delaying UCC until after lung aeration, has advantages over immediate UCC in mildly asphyxiated newborns, but its efficacy in asystolic newborns requiring CC is unknown. The aim of this study was to compare the cardiovascular response to CCs given prior to or after UCC in asystolic near-term lambs. Methods: Umbilical, carotid, pulmonary, and femoral arterial flows and pressures as well as systemic and cerebral oxygenation were measured in near-term sheep fetuses [139 ± 2 (SD) days gestation]. Fetal asphyxia was induced until asystole ensued, whereupon lambs received ventilation and CC before (PBCC; n = 16) or after (n = 12) UCC. Epinephrine was administered 1 min after ventilation onset and in 3-min intervals thereafter. The PBCC group was further separated into UCC at either 1 min (PBCC1, n = 8) or 10 min (PBCC10, n = 8) after return of spontaneous circulation (ROSC). Lambs were maintained for a further 30 min after ROSC. Results: The duration of CCs received and number of epinephrine doses required to obtain ROSC were similar between groups. After ROSC, we found no physiological benefits if UCC was delayed for 1 min compared to immediate cord clamping (ICC). However, if UCC was delayed for 10 min after ROSC, we found significant reductions in post-asphyxial rebound hypertension, cerebral blood flow, and cerebral oxygenation. The prevention of the post-asphyxial rebound hypertension in the PBCC10 group occurred due to the contribution of the placental circulation to a low peripheral resistance. As a result, left and right ventricular outputs continued to perfuse the placenta and were evidenced by reduced mean pulmonary blood flow, persistence of right-to-left shunting across the ductus arteriosus, and persistence of umbilical arterial and venous blood flows. Conclusion: It is possible to obtain ROSC after CC while the umbilical cord remains intact. There were no adverse effects of PBCC compared to ICC; however, the physiological changes observed after ROSC in the ICC and early PBCC groups may result in additional cerebral injury. Prolonging UCC after ROSC may provide significant physiological benefits that may reduce the risk of harm to the cerebral circulation.

Perinatal outcome of growth restricted fetuses with abnormal umbilical artery Doppler waveforms compared to growth restricted fetuses with normal umbilical artery Doppler waveforms at a tertiary referral hospital in urban Ethiopia.

Intrauterine growth restriction is defined as a fetal weight below the 10th percentile for a given gestational age and can be identified using umbilical artery Doppler velocimetry which is a non-invasive technique. The objective of this study was to determine the perinatal outcome of growth-restricted fetuses with abnormal umbilical artery Doppler study compared to those with normal umbilical artery Doppler waveforms at a tertiary referral hospital in Ethiopia. A prospective cohort study was conducted among pregnant mothers with fetal growth restriction admitted for labour and delivery from September 2018-February 2019. The data were entered and analyzed using SPSS version 23. After conducting descriptive analysis, exploring the entire data, and checking for, statistical associations between abnormal umbilical artery Doppler and outcome variables, multiple logistic regression was conducted to control for confounders. A total of 170 pregnant mothers complicated with growth-restricted fetuses were included in the study, among which 133 were with normal umbilical artery Doppler studies and 37 were with abnormal umbilical artery Doppler studies. Four (3%) of normal and 9(24.3%) of abnormal umbilical artery Doppler studies ended in perinatal death-value = 0.001. Twenty (15%) of normal and 24(64.9%) of abnormal umbilical artery Doppler study neonates required neonatal intensive care admission-value = 0.002. Growth restricted fetuses complicated with abnormal Doppler were two times more likely to require neonatal intensive care unit admissions compared to growth-restricted fetuses with normal umbilical artery Doppler flow, P-value 0.002, (OR = 2.059,95%CI 1.449-2.926). Growth restricted fetuses complicated with abnormal Doppler were four times more likely to end in early neonatal death compared to growth-restricted fetuses with normal umbilical artery Doppler flow, P-value 0.001, (OR = 4.136, 95%CI 3.423-4.998). However, the study is unmatched and there is a possibility of gestational age confounding the result and should be seen with the context of preterm morbidity and mortality. The abnormal umbilical artery Doppler waveform is associated with cesarean section delivery, neonatal intensive care unit admission, respiratory distress syndrome, neonatal sepsis, neonatal hyperbilirubinemia, and early neonatal death compared to normal umbilical artery Doppler flow.

A Correlational study of Umbilical Venous Flow Rate and Mode of Delivery

A Correlational study of Umbilical Venous Flow Rate and Mode of Delivery

Twelve Weeks of Reversed Umbilical Flow in a Fetal Growth Restriction Case Associated with Severe Periconceptional Maternal Anemia

We present a case of a patient diagnosed with severe intrauterine growth restriction and periconceptional severe anemia, where the fetal well-being features, including reversal of umbilical artery end-diastolic flow and abnormal cerebroplacental ratio, remained stationary for 12 weeks. We are not aware of reports with similar findings, and the professionals should take into consideration the possibility of a "frozen" fetal well-being for a long time. Possibly, in our case, the evolution may be due to the prompt correction of the chronic severe maternal anemia. This approach may offer the opportunity to prolong the pregnancy, even in cases with apparently imminent delivery, as the association of reversal of umbilical artery end-diastolic flow.

Maternal sleep disordered breathing assessed by Epworth Sleepiness Scale and abnormal feto-placental Dopplers

Objective Excessive daytime sleepiness is a frequently described phenomenon in pregnant women. The Epworth Sleepiness Scale (ESS) is a self reported standardized method of assessing sleep propensity and has been used extensively within pregnant populations. An elevated score is associated with sleep disordered breathing, as well as adverse obstetric and neonatal outcomes which may be indicative of a degree of placental dysfunction. Thus the aim of this study was to prospectively assess women using the Epworth questionnaire in conjunction with an ultrasound in both the second and third trimesters to determine if there was a difference in ESS scores across gestation and if a mid or late gestation assessment was correlated with Doppler ultrasound measures of fetal well-being. Materials and methods Participants were prospectively recruited from a tertiary obstetric hospital and completed both an Epworth questionnaire and ultrasound examination in the second and third trimesters. Results A total of 302 women took part in this cohort study. There was a statistically significant (p = .02) increase in ESS score across gestation. There was however no correlation identified in either the second or third trimester between ESS score and umbilical artery pulsatility index, middle cerebral artery pulsatility index, cerebroplacental ratio, umbilical venous flow, uterine artery pulsatility index or estimated fetal weight. A higher birth weight is associated with a higher ESS score in the second trimester but not in the third trimester (p = .03). Conclusions Maternal sleep disordered breathing assessed by the ESS score is only correlated with increased birth weight but not with fetal Doppler parameters in low risk pregnancies.

Expectant management in HELLP syndrome: predictive factors of disease evolution

Objective HELLP syndrome is a rare and severe pregnancy complication which exposes to severe maternal and fetal morbidity. Management of HELLP syndrome occurring before 34 weeks of gestation (WG) is still controversial but conservative management may be beneficial in patients with stable HELLP syndrome. The aim of the study was thus to identify which maternal and fetal prognostic factors could be predictive of HELLP syndrome evolution. Methods From 2003 to 2016, all patients with HELLP syndrome occurring between 26 and 34 WG were retrospectively enrolled. Study population was stratified according to obstetrical management. Patients in whom delivery was initiated within 48 h following diagnosis constituted the active management group. In the expectant management group, pregnancy was prolonged until maternal or fetal follow up indicated delivery. Results Ninety-nine patients were included in our study. Among them, 61 were managed expectantly. At baseline, the active management group was more likely to suffer from persistent hyperreflexia (p < .001), headache (p = .006) and confusion (p < .01). Moreover, this group was associated with worst biological and ultrasound features, namely decreased prothrombin ratio (p = .04), increased creatinine value (p = .01), and increased rates of pathological umbilical cord flow (p = .05) and abnormal ductus venosus flow (p = .007). After logistic regression, baseline significant prognostic factors were hyperreflexia (RR = 12.35; CI = 3.8 − 39.9), creatinine level (RR = 1.03; CI = 1002 − 1058) and abnormal umbilical cord flow (RR = 3.95; CI = 1.05 − 14.81). Last, expectant management leads to longer gestation time after diagnosis with an average value of 7.75 days without increasing maternal nor fetal mortality. Conclusion While expectant management in HELLP syndrome might be beneficial through its reduction of prematurity, it cannot be conducted in all patients. Identification of baseline parameters predictive of disease evolution is thus of tremendous importance to define which obstetrical approach should be prioritized.

T2*-weighted placental MRI: basic research tool or emerging clinical test for placental dysfunction?

Placental dysfunction is a common obstetric problem that complicates 5 - 10% of all pregnancies (1). It is a progressive condition, in which the fetal supply of oxygen and nutrients is insufficient to maintain normal fetal growth and organ development. The association between low birth weight and adverse neonatal outcome is well described (2). Moreover, there is evidence to support the hypothesis that common adult diseases such as metabolic syndrome and cardiovascular disease originate from abnormal fetal programming due to placental dysfunction - also known as Barker's Hypothesis (3). Currently, there is no available treatment to improve placental function. However, correct antenatal identification of placental dysfunction leads to a four-fold improvement in the neonatal outcome, as it allows for timely delivery and thereby reduces the risk of irreversible fetal organ damage (4). Current antenatal screening of placental dysfunction focuses on fetal weight estimates and fetal and umbilical Doppler flow measurements. However, fetal size does not exactly reflect placental function. In addition, in late onset placental dysfunction, Doppler flows usually remain normal (5).Therefore, additional markers that directly reflect placental function have the potential to considerably improve the antenatal screening of placental dysfunction. There is increasing interest in placental MRI, due to its potential to detect placental dysfunction in vivo. In particular, T2* weighted MRI has proven to be a simple and useful method to assess placental health, either studying the quantitative T2* relaxation time or the relative change in the raw T2* weighted signal in response to a given challenge (the BOLD response). T2* depends primarily on oxygenation but also on other tissue factors, including villous density, inhomogeneities in the distribution of oxygenated blood, magnetic field inhomogeneities, and the presence of other paramagnetic molecules (6). This paper aims to explain the physiological basis for changes in T2* weighted signal intensity in the placenta. Previous literature on T2* weighted placental MR is reviewed and reference values are provided for 1.5 and 3 T. Practical guidance on how to optimize the T2* weighted scans is included, and the clinical potential of T2* weighted imaging as an antenatal test of placental dysfunction is outlined. This article is protected by copyright. All rights reserved.

Significantly enlarged varix in the free-loop of the umbilical cord during the second trimester

Abstract Objectives Umbilical cord varix is an abnormal dilatation of the umbilical vein. There are two types of umbilical venous varix, of which the free-loop type is extremely rare, and the prognosis and etiology are unclear. In this report, we present a case of a significantly enlarged varix in the free loop of the umbilical cord found in the second trimester. Case presentation Cesarean section was performed at 28 weeks’ gestation due to enlargement of the varix and rapidly increased umbilical venous velocity at the outlet of the varix. Neonatal blood tests revealed anemia and high concentrations of D-dimer, and they were considered to be due to clot formation inside the umbilical cord venous varix. The neonate received blood transfusion but other neonatal course was generally favorable. Thrombus formation in the enlarged varix was due to the constriction of the umbilical cord. Conclusions This case showed that the assessment of umbilical venous flow velocity can be used for estimating the constriction of the umbilical vein and for determining the timing of delivery.

Correlation of Maternal BMI with Foetal Liver Blood Flow and Neonatal Adiposity in Normal Pregnancies and Pregnancies Complicated by Gestational Diabetes Mellitus and Foetal Growth Restriction

Introduction: The foetus exhibits a wide array of structural and functional adaptations in response to intrauterine conditions, towards protection of vital organs and maintaining the supply of essential nutrients. When oxygen is limited, foetal adaptations prioritise brain growth, irrespective of whether other essential nutrients are limited or not. The hypothesis for this study was that fatty acid synthesis occurs in foetal liver therefore if adaptive changes occur in the hepatic and umbilical flow it will affect fat deposition which will manifest as neonatal adiposity. Aim: Correlation of maternal Basal Metabolic Index (BMI) with Foetal liver blood flow and neonatal adiposity in normal pregnancies and pregnancies complicated by Gestational Diabetes Mellitus (GDM) and Foetal Growth Restriction (FGR) .Materials and Methods: An observational pilot study was carried out in a tertiary care referral hospital of Northern India. Antenatal women were recruited in three groups of singleton uncomplicated pregnancies (40), Women with GDM (31) and women with FGR (29). Maternal characteristics including pre-pregnancy BMI and obstetric ultrasound doppler study were recorded at 35 weeks gestation. The time-averaged maximum velocity (TAMX) was calculated for Umbilical Vein (UV) and Ductus Venosus (DV) as (Vmax) UV and (Vmax) DV. Blood flow (Q) was calculated as Q=h×(D/2)2×p×TAMX. The neonatal biometry and Skin Fold Thickness (SFT) was measured. Statistical techniques used were t-tests for analyses of dichotomous outcomes, Pearson’s correlation (r) and multivariate regression. Results: In mothers with higher DV shunting neonatal adiposity was significantly lower in the FGR group. In the uncomplicated group about 46% of variation in adiposity was explained by all the study variables and overall regression equation was statistically significant (p=0.004). Conclusion: Mothers with low BMI and normal umbilical and middle cerebral doppler flow had higher foetal hepatic flow to improve substrate deposition. DV shunting was significantly higher in hypoxic foetuses with reduced hepatic flow.

Comparative analysis of 2‐year outcomes in GRIT and TRUFFLE trials

ABSTRACTObjectiveTo explore the effect on perinatal outcome of different fetal monitoring strategies for early‐onset fetal growth restriction (FGR).MethodsThis was a cohort analysis of individual participant data from two European multicenter trials of fetal monitoring methods for FGR: the Growth Restriction Intervention Study (GRIT) and the Trial of Umbilical and Fetal Flow in Europe (TRUFFLE). All women from GRIT (n = 238) and TRUFFLE (n = 503) who were randomized between 26 and 32 weeks' gestation were included. The women were grouped according to intervention and monitoring method: immediate delivery (GRIT) or delayed delivery with monitoring by conventional cardiotocography (CTG) (GRIT), computerized CTG (cCTG) only (GRIT and TRUFFLE) or cCTG and ductus venosus (DV) Doppler (TRUFFLE). The primary outcome was survival without neurodevelopmental impairment at 2 years of age.ResultsGestational age at delivery and birth weight were similar in both studies. Fetal death rate was similar between the GRIT and TRUFFLE groups, but neonatal and late death were more frequent in GRIT (18% vs 6%; P < 0.01). The rate of survival without impairment at 2 years was lowest in pregnancies that underwent immediate delivery (70% (95% CI, 61–78%)) or delayed delivery with monitoring by CTG (69% (95% CI, 57–82%)), increased in those monitored using cCTG only in both GRIT (80% (95% CI, 68–91%)) and TRUFFLE (77% (95% CI, 70–84%)), and was highest in pregnancies monitored using cCTG and DV Doppler (84% (95% CI, 80–89%)) (P < 0.01 for trend).ConclusionsThis analysis supports the hypothesis that the optimal method for fetal monitoring in pregnancies complicated by early‐onset FGR is a combination of cCTG and DV Doppler assessment. Trial Registration: GRIT ISRCTN41358726 and TRUFFLE ISRCTN56204499. © 2019 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.

804: eFGR prevalence, prognosis and outcomes in a UK population dataset

Extremely early onset fetal growth restriction (eFGR; FGR < 3rd centile diagnosed prior to 28 weeks’ gestation, delivered prior to 33 weeks’ gestation) is a rare, but devastating pregnancy complication. Relatively little is known about its prevalence and prognosis, complicating counselling and management. In this study we have examined eFGR using a large national dataset combined with detailed fetal medicine measurements. Scottish national health service data (333,213 births from 2012-2017) was used to retrospectively determine prevalence and survival in eFGR. Prognostic information was derived from a single fetal medicine database of eFGR cases (n=183). Potential prognostic indicators of fetal death in-utero (FDIU) including presenting characteristics and longitudinal growth velocity were examined using logistic and mixed level regression. eFGR prevalence is 3 per 1000 pregnancies. Survival was >75% for those born after 29 weeks, and at a birthweight above 800g. Using the detailed eFGR database, sonographic factors predictive of FDIU at diagnosis (adjusted for gestation) included estimated fetal weight (EFW) (25g increment: aOR 0.71 (95% confidence interval 0.62-0.81)), umbilical artery end-diastolic flow (present compared to absent/reversed: 13.4 (3.70-48.6)) and mean uterine artery resistance index (0.1 increment: 2.05 (1.23-3.43)). A multivariate prognostic model using these factors correctly identified 43/45 cases of FDIU, with a positive likelihood ratio (LR) of 4.4 but a negative LR of 0.09. Growth velocity in pregnancies ending in FDIU was significantly slower (Figure 1), with a 50g/week increase in EFW between 24-26 weeks’ gestation associated with a 53% reduction in FDIU. This is the largest single study to date of eFGR prognosis prediction, and the first to determine eFGR prevalence in a population dataset. We have identified factors predictive of FDIU and proposed a potential model to use in clinical care which, due to its strong negative LR, would allow clinicians to reassure those with a normal result that pregnancy is likely to result in a live birth.

480: Umbilical artery Doppler discordance in fetal growth restriction

Contemporary antepartum surveillance for fetal growth restriction (FGR) consists of serial umbilical artery Doppler waveform assessments from a “free loop” (FL) of cord without regard to the specific artery being sampled. The primary objective of this study was to establish the frequency of discordant blood flow patterns between right and left umbilical arteries at the abdominal wall insertion site (AWI). Secondary aims included determining the frequency of discordance between FL and AWI patterns, and whether deterioration of Doppler waveforms occurred in a synchronous pattern. A descriptive prospective cohort study of patients diagnosed with IUGR between 23 0/7 -36 6/7 weeks gestation. Umbilical artery FL Doppler was obtained per routine clinical practice, with additional study waveforms acquired of both right and left umbilical arteries at the AWI. Doppler patterns were assigned 1 of 6 classifications. Baseline maternal demographics, obstetrical complications, gestational age at delivery, and neonatal birthweights were abstracted from medical records. Median gestational age at IUGR diagnosis was 31.4 weeks. Among the 70 participants, 50 (71.4%) had more than 1 Doppler measurement recorded, for a total of 238 examinations. At the initial study measurement, 14 patients (20%) had discordant AWI waveforms. When comparing AWI to FL measurements, discordance was found in 23 cases (33%). Progression of at least 1 AWI Doppler occurred in 23 patients (33%), and progression was discordant in 20 cases (29%; Table1). Frequent variability exists between arterial umbilical Doppler flow patterns in growth restricted fetuses, both at time of diagnosis and during subsequent measurements. The current study was descriptive, thus the clinical significance of this finding is indeterminate at present. Further investigations are needed to determine if umbilical artery Doppler discordance could conceivably represent an additional parameter for antepartum monitoring in fetal growth restriction.

Fetal Oxygen and Glucose Consumption in Human Pregnancy Complicated by Fetal Growth Restriction.

In healthy pregnancy, glucose and oxygen availability are essential for fetal growth and well being. However, how substrate delivery and fetal uptake are affected in human pregnancy complicated by fetal growth restriction (FGR) is still unknown. Here, we show that the human FGR fetus has a strikingly reduced umbilical uptake of both oxygen and glucose. In 30 healthy term and 32 FGR human pregnancies, umbilical volume flow (Qumb) and parallel umbilical vein (uv) and artery (ua) blood samples were obtained at elective Cesarean section to calculate fetal glucose and oxygen uptake as Qumb · Δ (uv-ua) differences. Umbilical blood flow was significantly lower in FGR pregnancy (-63%; P<0.001) but not when normalized for fetal body weight. FGR pregnancy had significantly lower umbilical oxygen delivery and uptake, both as absolute values (delivery: -78%; uptake: -78%) and normalized (delivery: -50%; uptake: -48%) for fetal body weight (all P<0.001). Umbilical glucose absolute delivery and uptake were significantly reduced (delivery: -68%; uptake: -72%) but only glucose uptake was decreased when normalized for fetal body weight (-30%; P<0.05). The glucose/oxygen quotient was significantly increased (+100%; P<0.05) while glucose clearance was significantly decreased (71%; P<0.001) in FGR pregnancy (both P<0.05). The human fetus in FGR pregnancy triggers compensatory mechanisms to reduce its metabolic rate, matching the proportion of substrate consumption relative to oxygen delivery as a survival strategy during complicated pregnancy.

Mathematical simulation of Doppler changes in late-onset smallness; progression patterns of cerebral and umbilical anomalies define two types of late-onset fetal growth restriction

Objective To evaluate the progression of Doppler abnormalities in fetuses with late-onset fetal smallness (SGA) that become growth restricted (FGR). Methods 524 Doppler examinations of the umbilical and cerebral arteries systems, belonging to 442 late-onset SGA fetuses after week 34, were studied, evaluating by means of the statistical difference with the respective abnormal centiles, the pattern of progression into abnormal Doppler values and the distribution and cumulative sum of Doppler anomalies according to the interval to delivery. Results Only one third (33.5%, N = 148) of late-onset SGA fetuses presented Doppler anomalies, suggesting that most were of constitutional origin. The most frequent progression pattern into abnormal Doppler (N = 127, 85.81%) was that in which only one system (umbilical or cerebral) became abnormal. Half of fetuses debuted with abnormal umbilical flow (52%, N = 77) and half with cerebral anomalies (47.97%, N = 71), which were more likely to appear later and at shorter intervals to delivery (p = .007). These progression patters defined two varieties of late-onset FGR (type I and II) with similar outcome but different birth weight centiles (BW centile = 2.51, SD 2.91 versus 3.97, SD 3.17, p < .01). Conclusion Two thirds of late-onset fetal smallness occurs without hemodynamic changes. In half of the remaining cases an initial cerebral vasodilation defines a group of fetuses with similar outcome but higher BW centile.

P06.12: Umbilical vein flow predicts adverse perinatal outcome in late fetal growth retardation at the time of the diagnosis

P06.12: Umbilical vein flow predicts adverse perinatal outcome in late fetal growth retardation at the time of the diagnosis

The effect of a maternal meal on fetal liver blood flow

IntroductionDuring the third trimester of development, the human fetus accumulates fat, an important energy reservoir during the early postnatal period. The fetal liver, perfused by the nutrient-rich and well-oxygenated blood coming directly from the placenta, is assumed to play a central role in these processes. Earlier studies have linked fetal liver blood flow with maternal nutritional status and response to the maternal oral glucose tolerance test. Our aim was to explore the effect of a regular maternal meal on fetal liver blood flow at two timepoints during the third trimester, representing the start and towards the end of the fetal fat accretion period. We also sought to explore the influence of prepregancy body mass index on how the maternal meal affects fetal liver blood flow.MethodsUsing ultrasound Doppler, we examined 108 healthy women with singleton pregnancies in gestational weeks 30 and 36. At each visit, the first examination was performed with the participant in a fasting state at 08.30 a.m., followed by a standard breakfast meal of approximately 400 kcal. The examination was repeated after 105 minutes. Umbilical vein and ductus venosus blood flow was estimated from diameter and blood flow velocity measurements. Fetal liver flow was calculated as umbilical vein flow minus ductus venosus flow, and change in liver blood flow as flow after minus before the meal. The total group was divided into a normal-weight group (prepregancy body mass index 18.5–25.0 kg/m2; n = 83) and an overweight group (prepregancy body mass index >25.0 kg/m2; n = 21). Four women with prepregancy body mass index <18.5 kg/m2 were excluded from these analyses. Non-parametric statistical hypothesis tests were used for group comparisons.ResultsFor the total group, we observed a significant increase in median (10th - 90th percentile) liver flow 28.9 (‒67.9–111.6) ml/min (p = 0.002) following the meal in week 36, but not in week 30, ‒2.63 (‒53.2–65.0) ml/min (p = 0.91). This result in turn yielded a statistically significant increase in delta liver flow from weeks 30 to 36 of 26.0 (‒107.1–146.6) ml/min (p = 0.008). The increase in postprandial liver flow was observed only in the normal-weight group in week 36. Accordingly, the delta liver flow values between the two weight groups were significantly different in week 36 (p = 0.006) but not in week 30 (p = 0.155). Among the normal-weight women, the increase in delta liver blood flow from weeks 30 to 36 was 39.3 (‒83.0–156.1) ml/min (p<0.001); in contrast, we observed no statistically significant change in the overweight group (‒44.5 (‒229.0–123.2) ml/min; p = 0.073). As a substitute for liver size, we divided the delta liver flow values by abdominal circumference and found no changes in the statistical significance results within or between the two weight groups.ConclusionIn our healthy study population, we observed a statistically significant difference in liver blood flow after maternal intake of a regular meal. This effect depended on gestational age and maternal prepregancy body mass index, but apparently was independent of liver size, based on abdominal circumference as a proxy measure.