Relationship between monitoring parameters and perinatal outcome in severe, early intrauterine growth restriction

Intermediate Diastolic Velocity as a Parameter of Cardiac Dysfunction in Growth-Restricted Fetuses

OBJECTIVE

To evaluate the intermediate intracardiac diastolic velocities in fetuses with growth restriction.

METHODS

Doppler waveforms of the two atrioventricular valves were obtained. Peak velocities of the E (early) and A (atrial) components, and the lowest intermediate velocity (IDV) between them, were measured in 400 normally grown and in 100 growth-restricted fetuses. The prevalence of abnormal IDV, E/IDV, and A/IDV ratios in fetuses presenting with perinatal death or acidemia at birth (pH ≤7.1) was estimated.

RESULTS

IDV was significantly lower and E/IDV ratios significantly higher in the two ventricles of growth-restricted fetuses with reduced diastolic velocities in the umbilical artery (p < 0.05). In 13 fetuses presenting with perinatal death or acidemia at birth, 11 (85%) had either an E/IDV or A/IDV ratio >95th percentile, whereas 5 (38%) showed absent or reversed atrial velocities in the ductus venosus (DV-ARAV; p < 0.04). Fetuses without DV-ARAV but with elevated E/IDV ratios in either ventricle were nearly 7-fold more likely to have perinatal demise or acidemia at birth (OR 6.9, 95% CI 1.4-34) than those with E/IDV ratios <95th percentile.

CONCLUSION

The E/IDV and A/IDV ratios in the two cardiac ventricles might provide information about the risk of perinatal demise or acidemia in growth-restricted fetuses.

Antenatal tests of fetal wellbeing

In current obstetric practice, there is frequently a need to assess fetal wellbeing. This is particularly so in those fetuses at risk, including the small-for-gestational-age fetus or the fetus of a mother who presents with reduced fetal movements or who has an obstetric complication such as pre-eclampsia. It is important that the clinician is able to assess fetal wellbeing in such cases, especially in preterm gestations, when inappropriate delivery could have serious adverse consequences. In this paper, we review the current evidence for the use and the limitations of widely used methods of antenatal monitoring including the use of cardiotocography, biophysical profile, and ultrasound-derived parameters including umbilical artery, middle cerebral artery, and ductus venosus Doppler flow.

2 year neurodevelopmental and intermediate perinatal outcomes in infants with very preterm fetal growth restriction (TRUFFLE): a randomised trial

BACKGROUND

No consensus exists for the best way to monitor and when to trigger delivery in mothers of babies with fetal growth restriction. We aimed to assess whether changes in the fetal ductus venosus Doppler waveform (DV) could be used as indications for delivery instead of cardiotocography short-term variation (STV).

METHODS

In this prospective, European multicentre, unblinded, randomised study, we included women with singleton fetuses at 26-32 weeks of gestation who had very preterm fetal growth restriction (ie, low abdominal circumference [<10th percentile] and a high umbilical artery Doppler pulsatility index [>95th percentile]). We randomly allocated women 1:1:1, with randomly sized blocks and stratified by participating centre and gestational age (<29 weeks vs ≥29 weeks), to three timing of delivery plans, which differed according to antenatal monitoring strategies: reduced cardiotocograph fetal heart rate STV (CTG STV), early DV changes (pulsatility index >95th percentile; DV p95), or late DV changes (A wave [the deflection within the venous waveform signifying atrial contraction] at or below baseline; DV no A). The primary outcome was survival without cerebral palsy or neurosensory impairment, or a Bayley III developmental score of less than 85, at 2 years of age. We assessed outcomes in surviving infants with known outcomes at 2 years. We did an intention to treat study for all participants for whom we had data. Safety outcomes were deaths in utero and neonatal deaths and were assessed in all randomly allocated women. This study is registered with ISRCTN, number 56204499.

FINDINGS

Between Jan 1, 2005 and Oct 1, 2010, 503 of 542 eligible women were randomly allocated to monitoring groups (166 to CTG STV, 167 to DV p95, and 170 to DV no A). The median gestational age at delivery was 30·7 weeks (IQR 29·1-32·1) and mean birthweight was 1019 g (SD 322). The proportion of infants surviving without neuroimpairment did not differ between the CTG STV (111 [77%] of 144 infants with known outcome), DV p95 (119 [84%] of 142), and DV no A (133 [85%] of 157) groups (ptrend=0·09). 12 fetuses (2%) died in utero and 27 (6%) neonatal deaths occurred. Of survivors, more infants where women were randomly assigned to delivery according to late ductus changes (133 [95%] of 140, 95%, 95% CI 90-98) were free of neuroimpairment when compared with those randomly assigned to CTG (111 [85%] of 131, 95% CI 78-90; p=0.005), but this was accompanied by a non-significant increase in perinatal and infant mortality.

INTERPRETATION

Although the difference in the proportion of infants surviving without neuroimpairment was non-significant at the primary endpoint, timing of delivery based on the study protocol using late changes in the DV waveform might produce an improvement in developmental outcomes at 2 years of age.

FUNDING

ZonMw, The Netherlands and Dr Hans Ludwig Geisenhofer Foundation, Germany.

Clinical characteristics and perinatal outcome of fetal hydrops

Objective

To investigate the clinical characteristics of fetal hydrops and to find the antenatal ultrasound findings predictive of adverse perinatal outcome.

Methods

This is a retrospective study of 42 women with fetal hydrops who delivered in a tertiary-referral center from 2005 to 2013. Fetal hydrops was defined as the presence of fluid collection in ≥2 body cavities: ascites, pleural effusion, pericardial effusion, and skin edema. Predictor variables recorded included: maternal characteristics, gestational age at diagnosis, ultrasound findings, and identifiable causes. Primary outcome variables analyzed were fetal death and neonatal death.

Results

The mean gestational age at diagnosis was 29.3±5.4 weeks (range, 18 to 39 weeks). The most common identifiable causes were cardiac abnormality (10), followed by syndrome (4), aneuploidy (3), congenital infection (3), twin-to-twin transfusion syndrome (3), non-cardiac anormaly (2), chorioangioma (2), inborn errors of metabolism (1), and immune hydrops by anti-E antibody isoimmunization (1). Thirteen cases had no definite identifiable causes. Three women elected termination of pregnancy. Fetal death occurred in 4 cases. Among the 35 live-born babies, only 16 survived (54.0% neonatal mortality rate). Fetal death and neonatal mortality rate was not significantly associated with Doppler velocimetry indices or location of fluid collection, but increasing numbers of fluid collection site was significantly associated with a higher risk of neonatal death.

Conclusion

The incidence of fetal hydrops in our retrospective study was 24.4 per 10,000 deliveries and the perinatal mortality rate was 61.9% (26/42). The number of fluid collection sites was the significant antenatal risk factor to predict neonatal death.

Doppler assessment of fetal aortic isthmus flow in twin

Objective

The purpose of this study was to investigate the aortic isthmus (AoI) flow difference between larger fetus and smaller fetus of twin; and to evaluate the predictive value of early diagnosis of hemodynamic change in twin growth.

Methods

This prospective study on 49 pairs of twin fetuses was performed to obtain AoI blood flow data. Cases with structural or chromosomal abnormalities and co-twin death were excluded. The interval from examination to delivery was within 4 weeks and 3 cases over 4 weeks interval were re-examined. Assessment of fetal AoI Doppler parameters were peak systolic velocity (PSV), end-diastolic velocity, times-averaged maximum velocities, pulsatility index (PI), and resistance index (RI). According to the direction of the diastolic flow in the AoI, antegrade and retrograde flow were made and was used to analyze the perinatal outcomes of each fetus. The predictive value of AoI Doppler parameters in predicting fetal growth was obtained by using ANOVA and logistic regression analysis of quantitative variables in each fetus of twins.

Results

There were significant differences in the gestational weeks at delivery, birth weight and the incidence of growth discordance over 20% or more between monochorionic twin and dichorionic twin. The AoI PI and RI were significantly higher in smaller fetus than in larger regardless of chorionicity. Retrograde flow was noted in 8 of 98 cases (8.2%) and the only one case was of the larger fetus and the others were smaller fetuses of twin. Significant correlations were found between the AoI PI and birthweight (P=0.018) and between the PSV and growth discordance (P=0.032). In monochorionic twin, linear correlation was shown between the AoI PI and birthweight (P=0.004) and between AoI PI and growth discordance (P=0.031). Also, the meaningful correlation between the PSV and birthweight (P=0.036) was found by using logistic regression analyses.

Conclusion

On the basis of our observation, AoI PI has revealed their hemodynamic status and this result may improve the understanding of growth patterns in twins.

IUGR management: new perspectives

AIM OF THE STUDY

Analyzing velocimetric (umbilical artery, UA; ductus venosus, DV; middle cerebral artery, MCA) and computerized cardiotocographic (cCTG) (fetal heart rate, FHR; short term variability, STV; approximate entropy, ApEn) parameters in intrauterine growth restriction, IUGR, in order to detect early signs of fetal compromise. POPULATION STUDY: 375 pregnant women assisted from the 28th week of amenorrhea to delivery and monitored through cCTG and Doppler ultrasound investigation. The patients were divided into three groups according to the age of gestation at the time of delivery, before the 34th week, from 34th to 37th week, and after the 37th week. Data were analyzed in relation to the days before delivery and according to the physiology or pathology of velocimetry. Statistical analysis was performed through the t-test, chi-square test, and Pearson correlation test (P < 0.05). Our results evidenced an earlier alteration of UA, DV, and MCA. The analysis between cCTG and velocimetric parameters (the last distinguished into physiological and pathological values) suggests a possible relation between cCTG alterations and Doppler ones. The present study emphasizes the need for an antenatal testing in IUGR fetuses using multiple surveillance modalities to enhance prediction of neonatal outcome.

Usefulness of fetal urine production measurement for prediction of perinatal outcomes in uteroplacental insufficiency

OBJECTIVES

To evaluate whether fetal urine production measurement is useful for predicting adverse outcomes in patients with uteroplacental insufficiency.

METHODS

We enrolled patients with uteroplacental insufficiency at 24 to 40 weeks' gestation and normal pregnancies matched for gestational age and divided them into 3 groups according to perinatal outcomes: group 1 (n = 141), a control group of normal pregnancies; group 2 (n = 29), uteroplacental insufficiency without adverse outcomes; and group 3 (n = 18), uteroplacental insufficiency with adverse outcomes. An adverse outcome was defined as 1 or more of the following: (1) cesarean delivery because of fetal distress; (2) admission to the neonatal intensive care unit; (3) cord arterial pH less than 7.15 at birth; and (4) low 5-minute Apgar score (<7). The fetal urine production rate was obtained by serial bladder volume measurement using virtual organ computer-aided analysis. For bladder volume determination, we scanned the bladder in the 3-dimensional mode and defined the bladder surface contour in the reference plane, repeating the rotation of the reference plane with an angle of 30° and determining the surface contour on each plane. Statistical methods, including the Mann-Whitney U test, Fisher exact test, χ(2) test, and Kruskal-Wallis analysis of variance, were used.

RESULTS

Group 3 had a lower mean fetal urine production rate than groups 1 and 2, whereas the urine production rate was not different between groups 1 and 2 (group 1, 49.0 mL/h; group 2, 59.4 mL/h; group 3, 20.7 mL/h; P < .001 between groups 1 and 3 and between groups 2 and 3). This difference between groups 2 and 3 remained significant after adjusting for the amniotic fluid index, umbilical artery Doppler pulsatility index, and presence of fetal growth restriction.

CONCLUSIONS

Uteroplacental insufficiency cases with adverse perinatal outcomes had a lower fetal urine production rate than those without adverse outcomes. This difference might be used to predict adverse perinatal outcomes in uteroplacental insufficiency.

A comparison of Doppler and biophysical findings between liveborn and stillborn growth-restricted fetuses

OBJECTIVE

The purpose of this study was to evaluate the surveillance characteristics that precede stillbirth in growth-restricted fetuses that receive integrated Doppler and biophysical profile scoring (BPS).

STUDY DESIGN

Nine hundred eighty-seven singleton pregnancies that were complicated by fetal growth restriction had multivessel Doppler scans (umbilical and middle cerebral arteries [MCA], ductus venosus, and umbilical vein) and BPS. Surveillance findings were compared between live births and stillbirths.

RESULTS

Forty-seven stillbirths occurred in 2 clusters, 37 at <34 weeks of gestation and 10 thereafter. Before 34 weeks of gestation, stillbirths had parallel escalation of umbilical artery and ductus venosus Doppler findings followed by abnormal BPS. At ≥34 weeks of gestation, only a decline in MCA pulsatility index was observed, and 75% of stillbirths were unanticipated by the BPS.

CONCLUSION

Before 34 weeks of gestation, multivessel Doppler abnormality anticipates an abnormal BPS and subsequent stillbirth. After 34 weeks of gestation, stillbirths occur after MCA brain-sparing in a shorter interval than predicted by a normal BPS. Recognition of these differences in clinical behavior requires consideration for the planning of monitoring intervals in preterm and term fetal growth restriction.

Survey on the current trends in managing intrauterine growth restriction

OBJECTIVE

To provide a snapshot of the current trends in managing intrauterine growth restriction (IUGR) and to assess the agreement on the gestational age and the way of delivery in different clinical scenarios.

METHODS

A PubMed search was performed to identify all original articles on IUGR in the last 6 years. The most active 20 authors were selected as experts and were invited to respond to a survey on their preferred gestational age for elective delivery in several IUGR cases depending on Doppler measurements (including umbilical artery (UA), middle cerebral artery, cerebroplacental ratio, uterine artery and ductus venosus), biophysical profile and cardiotocography.

RESULTS

15 of the 20 selected experts agreed to participate in the survey, of which 3 failed to meet the deadline to complete the survey. Management of IUGR was relatively uniform for abnormal UA, uterine artery or cerebroplacental ratio. Although average gestational age at delivery reflected a clear progression with accepted markers of severity, discrepancies of up to 4 weeks were found for abnormal middle cerebral artery Doppler and absent end-diastolic velocity in the UA, and of up to 8 weeks for reverse end-diastolic velocity in the UA and abnormalities in the ductus venosus Doppler.

CONCLUSIONS

Management of IUGR is still far from being uniform among centers, with most controversy surrounding the management of early-onset IUGR. There is a need of prospective studies to address this issue.

Fetal venous circulation in monochorionic twin pregnancies with placental insufficiency: prediction of acidemia at birth or intrauterine fetal death

OBJECTIVES

To investigate fetal venous Doppler measurements in monochorionic twin pregnancies complicated by placental insufficiency and the relationship between fetal venous flow and acidemia at birth or intrauterine fetal death.

METHODS

This was a prospective study of 18 monochorionic twin pregnancies with placental insufficiency. Inclusion criteria were monochorionic-diamniotic twin pregnancy, abnormal umbilical artery (UA) Doppler indices, intact membranes and absence of fetal congenital abnormalities. Cases of twin-to-twin transfusion syndrome were excluded. The following Doppler measurements were studied: UA pulsatility index (PI), ductus venosus PI, middle cerebral artery PI and peak systolic velocity, intra-abdominal umbilical vein (UV) time-averaged maximum velocity (TAMXV) and left portal vein (LPV) TAMXV. Doppler parameters were transformed into Z-scores (SD values from the mean) or multiples of the median according to normative references.

RESULTS

UA pH < 7.20 occurred in nine (25.0%) neonates, pH < 7.15 in four (11.1%) and intrauterine death in four (11.1%) fetuses. The UV-TAMXV and LPV-TAMXV Z-scores were significantly lower in the group with pH < 7.20 or intrauterine fetal death (-1.79 vs -1.22, P = 0.006 and -2.26 vs -1.13, P = 0.04, respectively). In cases with pH < 7.15 or intrauterine fetal death, UV pulsations were more frequent (50.0% vs 10.7%, P = 0.03) and UV-TAMXV Z-score was significantly lower (-1.89 vs -1.26, P = 0.003). Mixed effects logistic regression analysis, accounting for the paired nature of the outcomes for the two twins in each pregnancy, demonstrated that the UV-TAMXV Z-score significantly predicted UA pH at birth < 7.20 or intrauterine fetal death. The Doppler parameter that independently predicted pH < 7.15 or intrauterine fetal death was presence of pulsation in the UV.

CONCLUSION

UV Doppler parameters may predict acidemia at birth or intrauterine fetal death in monochorionic twins complicated by placental insufficiency.

Metabolomic profile of umbilical cord blood plasma from early and late intrauterine growth restricted (IUGR) neonates with and without signs of brain vasodilation

Objectives

To characterize via NMR spectroscopy the full spectrum of metabolic changes in umbilical vein blood plasma of newborns diagnosed with different clinical forms of intrauterine growth restriction (IUGR).

Methods

23 early IUGR cases and matched 23 adequate-for-gestational-age (AGA) controls and 56 late IUGR cases with 56 matched AGAs were included in this study. Early IUGR was defined as a birth weight <10^th centile, abnormal umbilical artery (UA) Doppler and delivery <35 weeks. Late IUGR was defined as a birth weight <10^th centile with normal UA Doppler and delivery >35 weeks. This group was subdivided in 18 vasodilated (VD) and 38 non-VD late IUGR fetuses. All AGA patients had a birth weight >10^th centile. ¹H nuclear magnetic resonance (NMR) metabolomics of the blood samples collected from the umbilical vein at delivery was obtained. Multivariate statistical analysis identified several metabolites that allowed the discrimination between the different IUGR subgroups, and their comparative levels were quantified from the NMR data.

Results

The NMR-based analysis showed increased unsaturated lipids and VLDL levels in both early and late IUGR samples, decreased glucose and increased acetone levels in early IUGR. Non-significant trends for decreased glucose and increased acetone levels were present in late IUGR, which followed a severity gradient when the VD and non-VD subgroups were considered. Regarding amino acids and derivatives, early IUGR showed significantly increased glutamine and creatine levels, whereas the amounts of phenylalanine and tyrosine were decreased in early and late-VD IUGR samples. Valine and leucine were decreased in late IUGR samples. Choline levels were decreased in all clinical subforms of IUGR.

Conclusions

IUGR is not associated with a unique metabolic profile, but important changes are present in different clinical subsets used in research and clinical practice. These results may help in characterizing comprehensively specific alterations underlying different IUGR subsets.

Fetal and umbilical Doppler ultrasound in high-risk pregnancies

BACKGROUND

Abnormal blood flow patterns in fetal circulation detected by Doppler ultrasound may indicate poor fetal prognosis. It is also possible false positive Doppler ultrasound findings could encourage inappropriate early delivery.

OBJECTIVES

The objective of this review was to assess the effects of Doppler ultrasound used to assess fetal well-being in high-risk pregnancies on obstetric care and fetal outcomes.

SEARCH METHODS

We updated the search of the Cochrane Pregnancy and Childbirth Group's Trials Register on 30 September 2013.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials of Doppler ultrasound for the investigation of umbilical and fetal vessels waveforms in high-risk pregnancies compared with no Doppler ultrasound.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the studies for inclusion, assessed risk of bias and carried out data extraction. Data entry was checked.

MAIN RESULTS

Eighteen completed studies involving just over 10,000 women were included. The trials were generally of unclear quality with some evidence of possible publication bias. The use of Doppler ultrasound in high-risk pregnancy was associated with a reduction in perinatal deaths (risk ratio (RR) 0.71, 95% confidence interval (CI) 0.52 to 0.98, 16 studies, 10,225 babies, 1.2% versus 1.7 %, number needed to treat (NNT) = 203; 95% CI 103 to 4352). There were also fewer inductions of labour (average RR 0.89, 95% CI 0.80 to 0.99, 10 studies, 5633 women, random-effects) and fewer caesarean sections (RR 0.90, 95% CI 0.84 to 0.97, 14 studies, 7918 women). No difference was found in operative vaginal births (RR 0.95, 95% CI 0.80 to 1.14, four studies, 2813 women), nor in Apgar scores less than seven at five minutes (RR 0.92, 95% CI 0.69 to 1.24, seven studies, 6321 babies).

AUTHORS' CONCLUSIONS

Current evidence suggests that the use of Doppler ultrasound in high-risk pregnancies reduced the risk of perinatal deaths and resulted in less obstetric interventions. The quality of the current evidence was not of high quality, therefore, the results should be interpreted with some caution. Studies of high quality with follow-up studies on neurological development are needed.

Evaluation of an optimal gestational age cut-off for the definition of early- and late-onset fetal growth restriction

OBJECTIVE

The terms early- and late-onset fetal growth restriction (FGR) are commonly used to distinguish two phenotypes characterized by differences in onset, fetoplacental Doppler, association with preeclampsia (PE) and severity. We evaluated the optimal gestational age (GA) cut-off maximizing differences among these two forms.

PATIENTS AND METHODS

A cohort of 656 consecutive singleton pregnancies with FGR was created. We used the decision tree analysis to evaluate the GA cut-off that best discriminated perinatal mortality, association with PE and adverse perinatal outcome (fetal demise, early neonatal death, neonatal acidosis at birth, and 5-min Apgar score <7).

RESULTS

We identified 32 weeks at diagnosis as the optimal cut-off, resulting in two groups with 7.1 and 0%, p < 0.001 perinatal mortality, 35.1 and 12.1%, p < 0.001 association with PE, and 13.4 and 4.6%, p < 0.001 composite adverse perinatal outcome. Abnormal versus normal umbilical artery (UA) Doppler classified two groups with 10.6 and 0.2%, p < 0.001 perinatal mortality, 50.0 and 11.8%, p < 0.001 association with PE, and 18.2 and 4.2%, p < 0.001 composite adverse perinatal outcome.

CONCLUSIONS

UA Doppler discriminated better the two forms of FGR with average early- and late-onset presentation, higher association with PE and poorer outcome. In the absence of UA information, a GA cut-off of 32 weeks at diagnosis maximizes differences between early- and late-onset FGR.

Cord blood B-type natriuretic peptide levels in placental insufficiency: correlation with fetal Doppler and pH at birth

OBJECTIVE

To examine the correlation of cardiac B-type natriuretic peptide (BNP) concentrations in umbilical cord blood at birth with fetal Doppler parameters and pH at birth.

STUDY DESIGN

Prospective cross-sectional study with the following inclusion criteria: women with a singleton pregnancy, placental insufficiency characterized by increased pulsatility index (PI) of the umbilical artery (UA), intact membranes, and absence of fetal abnormalities. The exclusion criteria kept out cases of newborns with postnatal diagnosis of abnormality and cases in which the blood analysis was not performed. The Doppler parameters used were the UA PI, middle cerebral artery (MCA) PI, cerebroplacental ratio (CPR), and ductus venosus (DV) PI for veins (PIV), all converted into zeta scores. Blood samples were obtained from the umbilical cord immediately after delivery to measure the pH of the UA and the BNP.

RESULTS

Thirty-two pregnancies with placental insufficiency were included, 21 (65%) with positive diastolic flow and 11 (35%) with absent or reversed end diastolic flow in the UA. The concentration of BNP correlated significantly with the UA PI z-score (rho=0.43, P=0.016), the CPR z-score (rho=-0.35, P=0.048), the DV PIV z-score (rho=0.61, P<0.001), pH at birth (rho=-0.39, P=0.031), and gestational age (rho=-0.51, P=0.003). In the multiple regression analysis, antenatal parameters were included; the DV PIV z-score (P=0.008) was found to be an independent parameter correlating with BNP at birth. Correlation between BNP and the DV PIV z-score was borne out by the regression equation Log[BNP]=2.34+0.13*DV (F=18.8, P<0.001). Correlation between BNP and pH at birth was confirmed by the regression equation Log[BNP]=21.36-2.62*pH (F=7.69, P=0.01).

CONCLUSION

The results suggest that fetal cardiac dysfunction identified by BNP concentrations at birth correlated independently with changes in DV PIV and correlated negatively with pH values at birth.

Ductus venosus versus cerebral transverse sinus Doppler velocimetry for predicting acidemia at birth in pregnancies complicated by placental insufficiency

OBJECTIVES

The objectives of this study is to compare ductus venosus (DV) and cerebral transverse sinus (CTS) Doppler velocimetry for predicting acidemia at birth in pregnancies complicated by placental insufficiency.

METHODS

A prospective cross-sectional study involving 69 cases. Doppler assessment of the DV and CTS was carried out in the last 24 hours prior to delivery. The sensitivity, specificity, positive and negative predictive values, and the accuracy and false-positive and false-negative rates were calculated for those parameters considered to be good predictors of acidemia. The McNemar test was used to compare the various parameters.

RESULTS

The DV pulsatility index(PI), S/A, and (S - A)/S ratios as well as the CTS PI and the (S - A)/S ratio were good predictors of acidemia. The comparison between DV and CTS showed that for pulsatility index for veins, the sensitivity was 52.4% versus 66.7%, p = 0.508; the specificity was 81.2% versus 77.1%, p = 0.774; and the accuracy was 72.5% versus 73.9%, p = 1.00. For the (S - A)/S ratio the sensitivity was 52.4% versus 52.4%, p = 1.00; the specificity was 85.4% versus 79.2%, p = 0.508; and the accuracy was 75.4% versus 71%, p = 0.647.

CONCLUSIONS

In pregnancies with placental insufficiency, the PI and the (S - A)/S ratio of both DV and CTS were equally effective in predicting acidemia at birth.

Hematologic profile of neonates with growth restriction is associated with rate and degree of prenatal Doppler deterioration

OBJECTIVE

To examine the relationship between hematologic parameters at birth and prenatal progression of Doppler abnormalities in fetal growth restriction (FGR).

METHODS

The study was a secondary analysis of FGR patients (abdominal circumference < 5th percentile and umbilical artery pulsatility index (UA-PI) elevation) with at least three examinations prior to delivery. Prenatal progression was classified as rapid, moderate or slow based on the interval between diagnosis and delivery and the extent of UA, middle cerebral artery and ductus venosus Doppler abnormalities. Associations between diagnosis-to-delivery interval, Doppler Z-scores, progression and hematologic parameters at birth were examined.

RESULTS

Of 130 patients, 54 (41.5%) had rapid, 51 (39.2%) moderate and 25 (19.2%) slow deterioration, delivering within 4, 6 and 9 weeks of diagnosis, respectively. The strongest association of moderate and rapid deterioration was with a low platelet count (r2  = 0.37 and 0.70, respectively; P < 0.0001). In patients with moderate deterioration, platelet count correlated inversely with UA-PI (ρ = -0.44, P = 0.001) and was lowest when end-diastolic velocity was absent. With rapid progression, platelet count correlated inversely with nucleated red blood cell count (ρ = -0.51, P < 0.001) but no longer with UA-PI.

CONCLUSION

Our observations suggest a relationship between prenatal clinical progression of FGR and hematologic abnormalities at birth. Accelerating cardiovascular deterioration is associated with decreased platelet count, which can be explained by placental consumption or dysfunctional erythropoiesis and thrombopoiesis.

The relationship of newborn adiposity to fetal growth outcome based on birth weight or the modified neonatal growth assessment score

OBJECTIVES

(1) Develop reference ranges of neonatal adiposity using air displacement plethysmography. (2) Use new reference ranges for neonatal adiposity to compare two different methods of evaluating neonatal nutritional status.

METHODS

Three hundred and twenty-four normal neonates (35-41 weeks post-menstrual age) had body fat (%BF) and total fat mass (FM, g) measured using air displacement plethysmography shortly after delivery. Results were stratified for 92 of these neonates with corresponding fetal biometry using two methods for classifying nutritional status: (1) population-based weight percentiles; and (2) a modified neonatal growth assessment score (m(3)NGAS(51)).

RESULTS

At the 50th percentile, %BF varied from 7.7% (35 weeks) to 11.8% (41 weeks), while the corresponding 50th percentiles for total FM were 186-436 g. Among the subset of 92 neonates, no significant differences in adiposity were found between small for gestational age (SGA), appropriate for gestational age (AGA), and large for gestational age (LGA) groups using population-based weight standards. Classification of the same neonates using m(3)NGAS(51) showed significant differences in mean %BF between corresponding groups.

CONCLUSIONS

Population-based weight criteria for neonatal nutritional status can lead to misclassifications on the basis of adiposity. A neonatal growth assessment score, that considers the growth potential of several anatomic parameters, appears to more effectively classify under- and over-nourished newborns.

Average acceleration and deceleration capacity of fetal heart rate in normal pregnancy and in pregnancies complicated by fetal growth restriction

OBJECTIVE

To study fetal heart rate (FHR), its short term variability (STV), average acceleration capacity (AAC), and average deceleration capacity (ADC) throughout uncomplicated gestation, and to perform a preliminary comparison of these FHR parameters between small-for dates (SFD) and control fetuses.

METHODS

Prospective observational study of 7 h FHR-recordings obtained with a fetal-ECG monitor in the second half of uncomplicated pregnancies (n = 90) and pregnancies complicated by fetal SFD (n = 30). FHR and STV were calculated according to established analysis. True beat-to-beat FHR, recorded at 1 ms accuracy, was used to calculate AAC and ADC using Phase Rectified Signal Averaging (PRSA). Mean values of FHR, STV, AAC, and ADC derived from recordings in SFD fetuses were compared with the reference curves.

RESULTS

Compared with the control group the mean z-scores for STV, AAC, and ADC in SFD fetuses were lower by 1.0 SD, 1.5 SD, and 1.7 SD, respectively (p < 0.0001 for all comparisons). In SFD fetuses, both the AAC and ADC z-scores were lower than the STV z-scores (p < 0.02 and p < 0.002, respectively).

CONCLUSIONS

Analysis of the AAC and ADC as recorded with a high resolution fECG recorder may differentiate better between normal and SFD fetuses than STV.

Reference ranges for time-related analysis of ductus venosus flow velocity waveforms in singleton pregnancies

OBJECTIVES

To investigate time intervals of ductus venosus (DV) flow velocity waveforms (FVW) in correlation to fetal heart rate and gestational age and to construct reference ranges for the second and third trimester. Furthermore, we investigate time intervals of FVW through the tricuspid valve.

METHODS

Flow velocity waveforms of the DV and through the tricuspid valve were recorded in 135 normal singleton fetuses between 17 and 38 weeks' gestation. Time intervals for systolic (S) and early diastolic (D) peaks were analyzed regarding acceleration time (acc-S for S, acc-D for D) and deceleration time (dec-S for S, dec-D for D), respectively. Similarly, time intervals for both peaks of right ventricular inflow were analyzed regarding acceleration time (acc-E for E-wave, acc-A for A-wave) and deceleration time (dec-E for E-wave, dec-A for A-wave), respectively.

RESULTS

In the DV, acc-D and dec-D increased significantly with gestational age. In tricuspid valve, acc-E and acc-A showed a significant increase with gestational age. All parameters except acc-S showed significant negative correlations with fetal heart rate.

CONCLUSION

With advancing gestational age, prolongation of the diastolic phase of DV-FVW and of the E-wave of tricuspid flow was observed, suggesting maturation of ventricular diastolic function. Time-related analysis of Doppler signals of DV-FVW may provide detailed insights into fetal cardiac function.

Fetal cardiac function: technical considerations and potential research and clinical applications

Fetal echocardiography was initially used to detect structural anomalies but has more recently also been proposed to assess fetal cardiac function. This review summarizes technical issues and limitations in fetal cardiac function evaluation, as well as its potential research and clinical applications. Functional echocardiography has been demonstrated to select high-risk populations and to be associated with outcome in several fetal conditions including intrauterine growth restriction, twin-to-twin transfusion syndrome, maternal diabetes, and congenital diaphragmatic hernia. Fetal heart evaluation is challenging due to the smallness and high heart rate of the fetus and restricted access to the fetus far from the transducer. Due to these limitations and differences in cardiac function which are related to fetal maturation, cardiovascular parameters should be validated in the fetus and used with caution. Despite these precautions, in expert hands and with appropriate ultrasound equipment, evaluation of cardiac function is feasible in most fetuses. Functional fetal echocardiography is a promising tool that may soon be incorporated into clinical practice. Research is warranted to further refine the contribution of fetal cardiac assessment to the diagnosis, monitoring, or prediction of outcomes in various fetal conditions.

Doppler assessment of the fetus with intrauterine growth restriction

OBJECTIVE

We sought to provide evidence-based guidelines for utilization of Doppler studies for fetuses with intrauterine growth restriction (IUGR).

METHODS

Relevant documents were identified using PubMed (US National Library of Medicine, 1983 through 2011) publications, written in English, which describe the peripartum outcomes of IUGR according to Doppler assessment of umbilical arterial, middle cerebral artery, and ductus venosus. Additionally, the Cochrane Library, organizational guidelines, and studies identified through review of the above were utilized to identify relevant articles. Consistent with US Preventive Task Force suggestions, references were evaluated for quality based on the highest level of evidence, and recommendations were graded.

RESULTS AND RECOMMENDATIONS

Summary of randomized and quasirandomized studies indicates that, among high-risk pregnancies with suspected IUGR, the use of umbilical arterial Doppler assessment significantly decreases the likelihood of labor induction, cesarean delivery, and perinatal deaths (1.2% vs 1.7%; relative risk, 0.71; 95% confidence interval, 0.52-0.98). Antepartum surveillance with Doppler of the umbilical artery should be started when the fetus is viable and IUGR is suspected. Although Doppler studies of the ductus venous, middle cerebral artery, and other vessels have some prognostic value for IUGR fetuses, currently there is a lack of randomized trials showing benefit. Thus, Doppler studies of vessels other than the umbilical artery, as part of assessment of fetal well-being in pregnancies complicated by IUGR, should be reserved for research protocols.

Longitudinal study of aortic isthmus Doppler in appropriately grown and small-for-gestational-age fetuses with normal and abnormal umbilical artery Doppler

OBJECTIVE

To establish reference ranges using longitudinal data for aortic isthmus (AoI) Doppler indices in appropriate-for-gestational-age (AGA) fetuses and to document the longitudinal trends in a cohort of small-for-gestational-age (SGA) fetuses with normal umbilical artery Doppler and in fetuses with intrauterine growth restriction (IUGR) and abnormal umbilical artery Doppler.

METHODS

AoI Doppler reference ranges were established from longitudinal data on 72 AGA singleton fetuses. Reliability of AoI Doppler flow measurements at two different sites and reproducibility between two operators was reviewed. A prospective longitudinal study of AoI Doppler indices in 48 SGA fetuses with normal umbilical artery Doppler and 10 IUGR fetuses was performed.

RESULTS

The AoI pulsatility index (PI) and peak systolic velocity (PSV) in AGA fetuses showed a significant increase with gestational age. Analysis of intra- and interoperator variability revealed no significant mean difference in measurements of AoI-PI or AoI-PSV. Observations of AoI-PI and AoI-PSV from SGA fetuses did not differ significantly from those of AGA or IUGR fetuses. Retrograde flow in the AoI did not predate changes in the ductus venosus in IUGR fetuses.

CONCLUSIONS

Reference ranges for fetal AoI Doppler parameters in AGA fetuses constructed using longitudinal data are consistent with those obtained from cross-sectional data. The AoI Doppler parameters in SGA fetuses did not differ from those in AGA fetuses. Preterm IUGR fetuses did not manifest alterations in AoI-PI or AoI-PSV prior to changes in biophysical profile or ductus venosus Doppler. Further large-scale prospective studies are needed to determine whether AoI Doppler parameters are of any value in timing delivery or reducing adverse neurodevelopmental outcome.

Impact of Doppler sonography on intrauterine management and neonatal outcome in preterm fetuses with intrauterine growth restriction

OBJECTIVES

To test the hypothesis that earlier delivery may be warranted to improve neonatal outcome of fetuses with intrauterine growth restriction (IUGR) with abnormal Doppler parameters.

METHODS

This was a retrospective cohort study of 110 fetuses with an antenatal diagnosis of IUGR due to placental insufficiency which had a very low birth weight (< 1500 g), delivered at the Department of Fetomaternal Medicine of the Medical University of Vienna, Austria, between January 1999 and July 2009. Doppler results before delivery were classified as follows: Group 1: abnormal umbilical artery (UA) pulsatility index (PI) more than 2 SD above the mean for normal reference data, or absent UA end-diastolic flow, both with normal middle cerebral artery (MCA) PI (mean ± 2 SD); Group 2: abnormal UA-PI > mean + 2 SD, or absent or reversed UA end-diastolic flow, with abnormal MCA-PI (< mean - 2 SD) and normal ductus venosus (DV) PI (mean ± 2 SD); Group 3: absent or reversed UA end-diastolic flow, with abnormal MCA-PI (< mean - 2 SD) and abnormal DV-PI (> mean + 2 SD) and/or absent or reversed end-diastolic DV flow. Pregnancy outcome was analyzed according to Doppler results.

RESULTS

Due to very poor prognosis, 19 fetuses underwent expectant management and died in utero. These were excluded from further analyses. Of the remaining 91 cases, 17 were in Doppler Group 1, 44 in Group 2 and 30 in Group 3. Within 4 weeks after delivery, 0/17 (0%) infants in Group 1 died, 2/44 (4.5%) infants in Group 2 died and 7/30 (23.3%) infants in Group 3 died (P = 0.019). None of the 42 Group 2 cases that delivered at or after 28 completed gestational weeks died within 4 weeks after delivery, in contrast to 4/20 (20.0%) Group 3 cases (P = 0.009). In comparison, among infants delivered before 27 completed gestational weeks, 2/2 (100%) Group 2 cases died and 3/10 (30.0%) Group 3 cases died; P = 0.152).

CONCLUSIONS

Doppler examinations are highly predictive in assessing the outcome of IUGR fetuses. From 28 completed gestational weeks, early delivery before the onset of fetal cardiac decompensation might be beneficial.

Duration of persistent abnormal ductus venosus flow and its impact on perinatal outcome in fetal growth restriction

OBJECTIVE

To study if the duration of individual Doppler abnormalities is an independent predictor of adverse outcome in fetal growth restriction (FGR) caused by placental dysfunction.

METHODS

This was a secondary analysis of patients with FGR (abdominal circumference < 5(th) percentile and umbilical artery (UA) pulsatility index (PI) elevation) who had at least three examinations before delivery. Days of duration of absent/reversed UA end-diastolic velocity (UA-AREDV), low middle cerebral artery PI (brain sparing), ductus venosus (DV) and umbilical vein Doppler abnormalities were related to stillbirth, major neonatal morbidity and intact survival.

RESULTS

One hundred and seventy-seven study participants underwent a total of 1069 examinations. The duration of an absent/reversed a-wave in the DV (DV-RAV) was significantly higher in stillbirths (median, 6 days) compared with intact survivors and those with major morbidity (median, 0 days for both; P = 0.006 and P = 0.001, respectively). Duration of brain sparing was also longer in stillbirth cases compared with intact survivors (median, 19 days vs. 9 days, P = 0.02). Stepwise multinomial logistic regression showed that gestational age at delivery was a significant codeterminant of outcome for all arterial Doppler abnormalities when the DV a-wave was antegrade. However, when present, the duration of DV-RAV was the only contributor to stillbirth (probability of stillbirth = 1/(1 + exp - (interval to delivery × 1.03 - 2.28)), r2 = 0.73). Receiver-operating characteristics curve statistics showed that a DV-RAV for > 7 days predicted stillbirth (100% sensitivity, 80% specificity, likelihood ratio = 5.0, P < 0.0001). In contrast, neither neonatal death nor neonatal morbidity was predicted by the days of persistent DV-RAV.

CONCLUSIONS

The duration of absent or reversed flow during atrial systole in the DV is a strong predictor of stillbirth that is independent of gestational age. While prematurity remains the strongest predictor of neonatal risks it is unlikely that pregnancy can be prolonged by more than 1 week in this setting.

Multivascular Doppler surveillance in high risk pregnancies

OBJECTIVES

Analysis of fetal arterial and venous Doppler predictability for adverse perinatal outcome.

METHODS

Blood flow in the uterine, umbilical and middle cerebral arteries, umbilical vein, ductus venosus and Galen vein were examined with in 72 h of delivery in 88 high-risk pregnancies. The managing clinicians were only informed about the results of the umbilical artery Doppler. The Doppler results were correlated to adverse perinatal outcome.

RESULTS

Doppler abnormalities were seen in both preterm and term pregnancies. Umbilical venous pulsations (n = 13) were strongly correlated to Apgar score <7 at 5 min, abnormal blood gases, need for ventilation assistance and operative delivery for fetal distress. Twenty-four fetuses had brain sparing in the middle cerebral artery, and forty-five had abnormal umbilical artery Doppler. These were correlated to admission in the neonatal intensive care unit, operative delivery and prematurity. Brain sparing in middle cerebral artery was also correlated to ventilation disturbances in the newborns. Abnormal ductus venosus blood velocity was only seen in 9 cases and not related to adverse outcome. Galen vein pulsations (n = 26) seem to appear earlier than pulsations in the umbilical vein and were not related to adverse outcome. conclusion: Umbilical vein pulsations were better correlated to adverse perinatal outcome than were other Doppler findings including ductus venosus.

Neurodevelopment following fetal growth restriction and its relationship with antepartum parameters of placental dysfunction

Placental dysfunction leading to fetal growth restriction (FGR) is an important risk factor for neurodevelopmental delay. Recent observations clarify that FGR evolves prenatally from a preclinical phase of abnormal nutrient and endocrine milieu to a clinical phase that differs in characteristics in preterm and term pregnancies. Relating childhood neurodevelopment to these prenatal characteristics offers potential advantages in identifying mechanisms and timing of critical insults. Based on available studies, lagging head circumference, overall degree of FGR, gestational age, and umbilical artery (UA), aortic and cerebral Doppler parameters are the independent prenatal determinants of infant and childhood neurodevelopment. While head circumference is important independent of gestational age, overall growth delay has the greatest impact in early onset FGR. Gestational age has an overriding negative effect on neurodevelopment until 32-34 weeks' gestation. Accordingly, the importance of Doppler status is demonstrated from 27 weeks onward and is greatest when there is reversed end-diastolic velocity in the UA or aorta. While these findings predominate in early-onset FGR, cerebral vascular impedance changes become important in late onset FGR. Abnormal motor and neurological delay occur in preterm FGR, while cognitive effects and abnormalities that can be related to specific brain areas increase in frequency as gestation advances, suggesting different pathophysiology and evolving vulnerability of the fetal brain. Observational and management studies do not suggest that fetal deterioration has an independent impact on neurodevelopment in early-onset FGR. In late-onset FGR further research needs to establish benefits of perinatal intervention, as the pattern of vulnerability and effects of fetal deterioration appear to differ in the third trimester.

The importance of venous Doppler velocimetry for evaluation of intrauterine growth restriction

The management of growth-restricted fetuses requires accurate diagnosis to optimize the timing of delivery. Doppler velocimetry is the only noninvasive method for assessing the fetoplacental hemodynamic status. This review will give a critical overview of the current knowledge on fetal venous blood flow in pregnancies complicated by in-trauterine growth-restricted fetuses. Adaptation of the circulation in intrauterine growth-restricted fetuses is described. Normal and abnormal venous Doppler waveforms are presented. Correlations of abnormal waveforms with the presence of acidemia and perinatal outcomes are emphasized. Limitations of venous Doppler velocimetry for optimizing the time for delivery and the perinatal outcome are also presented.

Intrauterine growth restriction: new concepts in antenatal surveillance, diagnosis, and management

Intrauterine growth restriction (IUGR) remains one of the main challenges in maternity care. Improvements have to start from a better definition of IUGR, applying the concept of the fetal growth potential. Customized standards for fetal growth and birthweight improve the detection of IUGR by better distinction between physiological and pathological smallness and have led to internationally applicable norms. Such developments have resulted in new insights in the assessment of risk and surveillance during pregnancy. Serial fundal height measurement plotted on customized charts is a useful screening tool, whereas fetal biometry and Doppler flow are the mainstay for investigation and diagnosis of IUGR. Appropriate protocols based on available evidence as well as individualized clinical assessment are essential to ensure good management and timely delivery.

Venous Doppler evaluation of the growth-restricted fetus

Evaluation of venous Doppler parameters has significantly contributed to the understanding of the vascular mechanisms that lead to fetal growth restriction (FGR) and subsequent fetal deterioration in the setting of progressive placental dysfunction. Venous redistribution of umbilical venous blood flow away from the fetal liver precedes fetal growth delay. Venous Doppler examination allows adjustment of monitoring intervals in recognition of accelerating fetal deterioration. The timing of delivery in early-onset FGR remains challenging because gestational age has an overriding effect on the neonatal outcome until the late second trimester and randomized trials of specific delivery triggers are lacking.

New computerized fetal heart rate analysis for surveillance of intrauterine growth restriction

OBJECTIVE

Decreased fetal heart rate variability is associated with higher perinatal morbidity and mortality in intrauterine growth restriction (IUGR). This study used a new method [phase-rectified signal averaging (PRSA)] to calculate acceleration- and deceleration-related fluctuations of the fetal heart rate.

METHOD

Cardiotocograms from 74 growth-restricted and 161 normal fetuses were included. Both groups were matched for gestational age. The transformed PRSA signal was quantified by the acceleration-related parameter-averaged acceleration capacity (AAC) and compared to the standard short-term variation (STV). Mann-Whitney test and receiver operator characteristic (ROC) curves were used for statistical analysis.

RESULTS

For AAC, the median values of the IUGR group and control group were 1.97 bpm [interquartile range (IQR): 1.66-2.23] and 2.49 bpm (IQR: 2.24-2.72), respectively. For STV, these values were 5.44 ms (IQR: 4.49-7.38) and 7.79 ms (IQR: 6.35-9.66), respectively. The area under the ROC curve was 81.4% for AAC and 70.5% for STV.

CONCLUSION

The results of AAC are in both groups comparable to STV. Longitudinal studies are needed to investigate the association of AAC with the clinical outcome of the newborn.

[Cerebral palsy and perinatal asphyxia (II--Medicolegal implications and prevention)]

Obstetric litigation is a growing problem in developed countries and its escalating cost together with increasing medical insurance premiums is a major concern for maternity service providers, leading to obstetric practice cessation by many practitioners. Fifty-four to 74 % of claims are based on cardiotocographic (CTG) abnormalities and their interpretation followed by inappropriate or delayed reactions. A critical analysis is performed about the nine criteria identified by the American College of Obstetricians and Gynecologists and the American Academy of Pediatrics in their task force on Neonatal Encephalopathy and Cerebral Palsy: four essential criteria defining neonatal asphyxia and five other suggesting an acute intrapartum event sufficient to cause cerebral palsy in term newborns. The importance of placental histologic examination is emphasized in order to confirm sudden catastrophic events occurring before or during labor or to detect occult thrombotic processes affecting the fetal circulation, patterns of decreased placenta reserve and adaptative responses to chronic hypoxia. It may also exclude intrapartum hypoxia by revealing some histologic patterns typical of acute chorioamnionitis and fetal inflammatory response or compatible with metabolic diseases. Magnetic resonance imaging (MRI) of the infant's damaged brain is very contributive to elucidate the mechanism and timing of asphyxia in conjunction with the clinical picture, by locating cerebral injuries predominantly in white or grey matter. Intrapartum asphyxia is sometimes preventable by delivering weak fetuses by cesarean sections before birth, by avoiding some "sentinel" events, and essentially by responding appropriately to CTG anomalies and performing an efficient neonatal resuscitation. During litigation procedures, it is necessary to have access to a readable CTG, a well-documented partogram, a complete analysis of umbilical cord gases, a placental pathology and an extensive clinical work-up of the newborn infant including cerebral MRI. Malpractice litigation in obstetric care can be reduced by permanent CTG education, respect of national CTG guidelines, use of adjuncts such as fetal blood sampling for pH or lactates, regular review of adverse events in Clinical Risk Management (CRM) groups and periodic audits about low arterial cord pH in newborns, admission to neonatal unit, the need for assisted ventilation and the decision-to-delivery interval for emergency operative deliveries. Considering the fast occurrence of fetal cerebral hypoxic injuries, and thus despite an adequate management, many intrapartum asphyxias will not be preventable. Conversely, well-documented hypoxic-ischemic brain insults during the antenatal period do not automatically exclude intrapartum suboptimal obstetric care.