R. Cruz‐Martinez

Fetal brain Doppler to predict cesarean delivery for nonreassuring fetal status in term small-for-gestational-age fetuses.

OBJECTIVE: To estimate the value of fetal brain Doppler in predicting the risk of cesarean delivery for nonreassuring fetal status and neonatal acidosis after labor induction in small-for-gestational-age fetuses with normal umbilical artery Doppler. METHODS: Fetal brain Doppler parameters, including cerebral tissue perfusion measured by fractional moving blood volume, cerebroplacental ratio, and middle cerebral artery pulsatility index, were evaluated before labor induction in a cohort of 210 term small-for-gestational-age fetuses with normal umbilical artery Doppler and 210 control participants matched by gestational age. The value of the cerebral Doppler indices to predict the risk of cesarean delivery, cesarean delivery for nonreassuring fetal status, and neonatal acidosis was analyzed. RESULTS: Overall, small-for-gestational-age fetuses showed a significant higher incidence of cesarean delivery (37.6% compared with 19.5%, P<.001), cesarean delivery for nonreassuring fetal status (29% compared with 4.8%, P<.001), and neonatal acidosis (7.6% compared with 2.4%, P=.03) than control participants. Within the small-for-gestational-age group, middle cerebral artery vasodilation was associated with the highest risk of cesarean delivery (67.7% compared with 32.4%, P<.001) and cesarean delivery for nonreassuring fetal status (58.1% compared with 24%, P<.001). In the subgroup of normal middle cerebral artery, incorporation of cerebroplacental ratio further distinguished two groups with different risks of cesarean delivery (51.4% compared with 27.5%, P<.01) and cesarean delivery for nonreassuring fetal status (37.8% compared with 20.4%, P=.01). Middle cerebral artery vasodilation was associated with increased risk of neonatal acidosis (odds ratio, 9.0). Fractional moving blood volume was not associated with the risk of cesarean delivery for nonreassuring fetal status or neonatal acidosis. CONCLUSION: Evaluation of brain Doppler indices before labor induction discriminates small-for-gestational-age fetuses at high risk of cesarean delivery for nonreassuring fetal status and neonatal acidosis. LEVEL OF EVIDENCE: II

Longitudinal changes in uterine, umbilical and fetal cerebral Doppler indices in late‐onset small‐for‐gestational age fetuses

To determine the longitudinal trends and rates of conversion of normal to abnormal uterine (UtA), umbilical (UA) and middle cerebral artery (MCA) Doppler velocimetry throughout the third trimester in late‐onset small‐for‐gestational‐age (SGA) fetuses.

Neurobehavior in Term, Small-for-Gestational Age Infants With Normal Placental Function

OBJECTIVE: The goal was to evaluate the neurobehavioral outcomes of term, small-for-gestational age (SGA) newborns with normal placental function. METHODS: A cohort of consecutive term SGA newborns with normal prenatal umbilical artery Doppler ultrasound findings was created and compared with a group of term infants with size appropriate for gestational age, who were sampled from our general neonatal population. Neonatal behavior was evaluated at corrected age of 40 ± 1 weeks with the Neonatal Behavioral Assessment Scale. The effect of the study group on each Neonatal Behavioral Assessment Scale area was adjusted, through multivariate analysis of covariance, for smoking during pregnancy, maternal BMI, socioeconomic level, onset of labor, mode of delivery, use of epidural anesthetic medication, gestational age at delivery, postnatal age (in days) at evaluation, and gender. RESULTS: A total of 202 newborns (102 SGA and 100 appropriate for gestational age) were included. All of the neurobehavioral areas studied were poorer in the SGA group, with significance for attention, habituation, motor, social-interactive, and regulation of state. The average mean differences in scores between the study groups were 0.77 (95% confidence interval: 0.38–1. 14) for attention, 0.64 (95% confidence interval: 0.13–1.14) for habituation, 0.52 (95% confidence interval: 0.31–0.74) for motor, 0.95 (95% confidence interval: 0.54–1.37) for social-interactive, and 0.68 (95% confidence interval: 0.23–1.13) for regulation of state. These differences remained significant after adjustment for potential confounders. CONCLUSION: Term SGA newborns with no signs of placental insufficiency had poorer neurobehavioral competencies, which suggests delayed neurologic maturation.

Cerebral blood perfusion and neurobehavioral performance in full-term small-for-gestational-age fetuses

OBJECTIVE The purpose of this study was to evaluate changes in cerebral blood perfusion and middle cerebral artery (MCA) Doppler in full-term small-for-gestational-age fetuses (SGA) and to explore their association with neonatal neurobehavioral performance. STUDY DESIGN Frontal brain perfusion that was measured by fractional moving blood volume (FMBV) and MCA Doppler pulsatility index were assessed in 60 SGA fetuses with normal umbilical artery Doppler results that were matched with adequate-for-gestational-age fetuses. Neonates were evaluated with the Neonatal-Behavioral-Assessment-Scale (NBAS). RESULTS The proportion of SGA fetuses with increased FMBV (35% vs 5%; P < .001) and decreased MCA Doppler pulsatility index (15% vs 1.7%; P < .01) was significantly higher. SGA fetuses showed poorer NBAS scores in all areas. Increased FMBV identified SGA fetuses with the highest risks of abnormal NBAS in social-interactive (odds ratio, 7.8), attention (odds ratio, 22.8), and state-organization (odds ratio, 25.0). Abnormal MCA Doppler identified SGA with abnormal scores in motor area (odds ratio, 10.7). CONCLUSION Increased brain blood perfusion discriminates SGA fetuses that are at risk for abnormal neurobehavior.

Estimated weight centile as a predictor of perinatal outcome in small‐for‐gestational‐age pregnancies with normal fetal and maternal Doppler indices

To evaluate the risk of adverse perinatal outcome according to estimated fetal weight (EFW) in a cohort of term small‐for‐gestational‐age (SGA) pregnancies with normal umbilical, fetal middle cerebral and maternal uterine artery Doppler indices.

Neurobehavioral outcomes in preterm, growth‐restricted infants with and without prenatal advanced signs of brain‐sparing

To evaluate the neurobehavioral outcomes of preterm infants with intrauterine growth restriction (IUGR), with and without prenatal advanced brain‐sparing.

Normal Reference Ranges from 11 to 41 Weeks’ Gestation of Fetal Left Modified Myocardial Performance Index by Conventional Doppler with the Use of Stringent Criteria for Delimitation of the Time Periods

Objective: To establish normal reference intervals of the fetal left modified myocardial performance index (MPI) with the use of stringent criteria for delimitation of the time periods. Study Design: A cohort of consecutive singleton fetuses was created including at least 20 fetuses for each completed week of gestation between 11 and 41 weeks. The isovolumetric contraction time (ICT), isovolumetric relaxation time (IRT), and ejection time (ET) were calculated using the clicks of the mitral and aortic valves as landmarks, and the MPI was calculated as follows: (ICT + IRT)/ET. Normal reference ranges for the MPI and its individual components were constructed by means of regression analysis of the mean and standard deviation against gestational age (GA). Results: A total of 730 fetuses were included. After a natural logarithmic transformation, a third degree cubic polynomial model (loge mean MPI = 0.0477 × GA – 0.002565 × GA2 + 0.000043 × GA3 –1.22, with GA measured in weeks) was selected to fit our data. There was a progressive increase in the mean MPI from 11 weeks (mean, 0.39; 95th centile, 0.51) to 41 weeks (mean, 0.55; 95th centile, 0.78) of gestation. While the mean ICT and IRT values increased with GA from 25 to 32 ms and from 39 to 51 ms, respectively, the ET showed an initial increase until 30 weeks and a progressive decrease thereafter. Conclusion: Normative references of left modified MPI from 11 to 41 weeks of gestation are provided, which could be useful in the assessment of cardiac function in fetuses.

Evaluation of conventional Doppler fetal cardiac function parameters: E/A ratios, outflow tracts, and myocardial performance index.

Structural evaluation of the fetal heart is well established. Functional evaluation using pulsed-wave Doppler may also be performed. E/A ratios express the relationship between the maximal velocities of the E and A waveforms of ventricular filling. In normal fetuses, E/A ratios are usually <1 but show a constant increment during gestation, mainly related to the increment of the E wave. In intrauterine growth restriction (IUGR) fetuses, E/A ratios are lower compared to values in normally grown fetuses at the same gestational age. Cardiac outflows provide information on the time-velocity integral that, combined with the vessel area, allows calculation of the left and right cardiac outputs. In normal fetuses there is a predominance of the right ventricle (55–60%) in contributing to the combined cardiac output. In IUGR fetuses this predominance shifts to the left ventricle in order to increase the flow to the upper part of the fetal body and brain. The myocardial performance index (MPI) also provides information on systolic and diastolic cardiac function. The MPI is an early and consistent marker of cardiac dysfunction which becomes altered in early stages of chronic hypoxia or in cases with cardiac overload such as in twin-to-twin transfusion syndrome.

Risk of Perinatal Death in Early-Onset Intrauterine Growth Restriction according to Gestational Age and Cardiovascular Doppler Indices: A Multicenter Study

Objective: To assess the value of gestational age and cardiovascular Doppler indices in predicting perinatal mortality in a multicenter cohort of early-onset intrauterine growth-restricted (IUGR) fetuses. Methods: A multicenter prospective cohort study including 157 early-onset (<34 weeks) IUGR cases with abnormal umbilical artery (UA) Doppler was conducted. Cardiovascular assessment included the ductus venosus (DV), the aortic isthmus flow index (IFI), and the myocardial performance index (MPI). Isolated and combined values to predict the risk of perinatal death were evaluated by logistic regression and by decision tree analysis, where the gestational age at delivery, UA, and middle cerebral artery (MCA) were also included as covariates. Results: Perinatal mortality was 17% (27/157). All parameters were significantly associated with perinatal death, with individual odds ratios (OR) of 25.2 for gestational age below 28 weeks, 12.1 for absent/reversed DV atrial flow, 5.3 for MCA pulsatility index <5th centile, 4.6 for UA absent/reversed diastolic end-flow, 1.8 for IFI <5th centile, and 1.6 for MPI >95th centile. Decision tree analysis identified gestational age at birth as the best predictor of death (<26 weeks, 93% mortality; 26–28 weeks, 29% mortality, and >28 weeks, 3% mortality). Between 26 and 28 weeks, DV atrial flow allowed further stratification between high (60%) and low risk (18%) of mortality. Conclusions: Gestational age largely determines the risk of perinatal mortality in early-onset IUGR before 26 weeks and later than 28 weeks of gestation. The DV may improve clinical management by stratifying the probability of death between 26 and 28 weeks of gestation.

Sequence of changes in myocardial performance index in relation to aortic isthmus and ductus venosus Doppler in fetuses with early-onset intrauterine growth restriction

To explore the sequence of changes in myocardial performance index (MPI) and aortic isthmus (AoI) and ductus venosus (DV) flow in fetuses with early‐onset intrauterine growth restriction (IUGR).