Estimation of the growth rate in fetuses with an abnormal cerebroplacental ratio compared to those with suspected growth restriction without evidence of centralization of blood flow

Longitudinal change in cerebro-placental ratio (CPR) between 37 and 40 weeks of pregnancy is associated with non-reassuring fetal status and increased risk of cesarean section

OBJECTIVE

To evaluate in low-risk pregnancies if longitudinal change in cerebro-placental ratio (CPR) between 37 and 40 weeks of pregnancy is associated with cesarean section (CS) for non-reassuring fetal status (NRFS) during labor.

METHODS

This is a prospective observational study of women with singleton low-risk pregnancies who underwent an ultrasound scan at 36 + 0 to 37 + 6 and 39 + 0 to 41 + 6 weeks of pregnancy, when the CPR was calculated from the middle cerebral artery (MCA) and umbilical artery (UA) pulsatility indices. Managing professionals were kept blinded to the Doppler results. The association of the longitudinal change between both CPR (z-velocity) to CS for NRFS was evaluated by logistic regression.

RESULTS

A total of 401 pregnancies were included. The mean time interval between both CPR evaluations was 21 days (SD 7). A CS for fetal distress was performed in 7% of pregnancies. Independent of the CPR at 37 weeks, the likelihood of CS for fetal distress was significantly decreased by the longitudinal changes from 37 to 40 weeks (OR 0.61, 95%CI 0.4-0.92; p=.018). This association remained significant after further adjustment for potential confounders (nulliparity, maternal weight at booking and estimated fetal weight at 37): (OR 0.64, 95%CI 0.41-0.98; p=.044).

CONCLUSIONS

The longitudinal change of CPR between 37 and 40 weeks is associated with the need for CS for NRFS during labor.

Fetal Growth Velocity according to the Mode of Assisted Conception

INTRODUCTION

Pregnancies conceived through assisted reproductive techniques (ARTs) are on the rise worldwide and have been associated with a higher risk of placental-related disease in the third trimester.

METHODS

A cohort was created of singleton pregnancies after assisted reproduction, admitted at our institution for delivery, between January 2020 and August 2022. Fetal growth velocity from the second trimester to delivery was compared against a gestational-age-matched group of pregnancies spontaneously conceived according to the origin of the selected oocyte (i.e., autologous vs. donated).

RESULTS

125 singleton pregnancies conceived through ART were compared to 315 singleton spontaneous conceptions. Overall, after adjusting for possible confounders, multivariate analysis demonstrated that ART pregnancies had a significantly lower estimated fetal weight (EFW) z-velocity from the second trimester to delivery (adjusted mean difference = -0.002; p = 0.035) and a higher frequency of EFW z-velocity in the lowest decile (adjusted OR = 2.32 [95% CI, 1.15-4.68]). Also, when ART pregnancies were compared according to the type of oocyte, those conceived with donated oocytes showed a significantly lower EFW z-velocity from the second trimester to delivery (adjusted mean difference = -0.008; p = 0.001) and a higher frequency of EFW z-velocity in the lowest decile (adjusted OR = 5.33 [95% CI, 1.34-21.5]).

CONCLUSIONS

Pregnancies achieved through ART exhibit a pattern of lower growth velocity across the third trimester, especially those conceived with donated oocytes. The former represents a sub-group at the highest risk of placental dysfunction that may warrant closer follow-up.

Diagnostic Tests in the Prediction of Neonatal Outcome in Early Placental Fetal Growth Restriction

Background and Objectives: Monitoring pregnancies with fetal growth restriction (FGR) presents a challenge, especially concerning the time of delivery in cases of early preterm pregnancies below 32 weeks. The aim of our study was to compare different diagnostic parameters in growth-restricted preterm neonates with and without morbidity/mortality and to determine sensitivity and specificity of diagnostic parameters for monitoring preterm pregnancies with early preterm fetal growth restriction below 32 weeks. Materials and Methods: Our clinical study evaluated 120 cases of early preterm deliveries, with gestational age ≤ 32 + 0 weeks, with prenatally diagnosed placental FGR. All the patients were divided into three groups of 40 cases each based on neonatal condition,: I-Neonates with morbidity/mortality (NMM); II-Neonates without morbidity with acidosis/asphyxia (NAA); III-Neonates without neonatal morbidity/acidosis/asphyxia (NWMAA). Results: Amniotic fluid index (AFI) was lower in NMM, while NWMAA had higher biophysical profile scores (BPS). UA PI was lower in NWMAA. NWMAA had higher MCA PI and CPR and fewer cases with CPR <5th percentile. NMM had higher DV PI, and more often had ductus venosus (DV) PI > 95th‱ or absent/reversed A wave, and pulsatile blood flow in umbilical vein (UV). The incidence of pathological fetal heart rate monitoring (FHRM) was higher in NMM and NAA, although the difference was not statistically significant. ROC calculated by defining a bad outcome as NMM and a good outcome as NAA and NWMAA showed the best sensitivity in DV PIi. ROC calculated by defined bad outcome in NMM and NAA and good outcome in NWMAA showed the best sensitivity in MCA PI. Conclusions: In early fetal growth restriction normal cerebral blood flow strongly predicts good outcomes, while pathological venous blood flow is associated with bad outcomes. In fetal growth restriction before 32 weeks, individualized expectant management remains the best option for the optimal timing of delivery.

Intracranial ultrasound abnormalities and mortality in preterm infants with and without fetal growth restriction stratified by fetal Doppler study results

OBJECTIVE

To evaluate whether fetal growth restriction (FGR) with or without abnormal Dopplers is associated with intracranial abnormalities and death in premature infants.

STUDY DESIGN

Premature infants with and without FGR born between 2016 and 2019 were included. Primary outcome was death, severe intraventricular hemorrhage (IVH) or periventricular leukomalacia (PVL). Groups were compared using standard bivariate testing and multivariable regression.

RESULTS

Among 168 FGR and 560 non-FGR infants, FGR infants with abnormal Dopplers had an increased incidence of death, severe IVH or PVL compared to non-FGR infants (13% (16/123) vs. 7% (41/560); p = 0.03) while FGR infants with normal Dopplers had a nonsignificant decrease. In a logistic regression model, FGR with abnormal Dopplers was associated with more than three times higher odds of death, severe IVH or PVL (OR 3.2, 95% CI 1.54,6.49; p < 0.001).

CONCLUSIONS

Growth-restricted infants with abnormal Dopplers had an increased risk of death, intracranial abnormalities, and prematurity-related morbidities.

Effect of a standardized maternal meal on fetal middle cerebral artery Doppler indices: A single-blinded crossover study

Objective

Measures of Doppler blood flow velocity profiles are an integral part of monitoring fetal well-being during pregnancy. These examinations are performed at different times of the day and at different maternal meal states. In uncomplicated pregnancies, we assessed the effect of a standardized maternal meal on middle cerebral artery (MCA) and umbilical artery (UA) Doppler blood flow velocity pulsatility indices (PIs) and MCA peak systolic velocity (PSV).

Methods

In this prospective single-blinded crossover study 25 healthy women were examined at 36 weeks of pregnancy. The first examination was performed in the morning following overnight fast, and repeated after extended fast (state A), and after a standard breakfast meal (state B).

Results

Irrespective of maternal prandial status, the MCA-PI values were lower in the 2^nd compared to the 1^st examination (-0.187; p = 0.071, and -0.113; p = 0.099, state A and B, respectively). Compared to the values in the 1^st examination, the UA-PI values, were higher after extended fast (0.014; p = 0.436), and lower post-prandially (-0.036; p = 0.070). The difference (state B minus state A) between the meal states were not significant (0.074; p = 0.487 and -0.050; p = 0.058, for MCA-PI and UA-PI, respectively). Adjusting for the possible influence of fetal heart rate on MCA-PI and UA-PI, the differences between meal states remained non-significant (p = 0.179, p = 0.064, respectively). The MCA-PSV values increased after the meal (6.812; p = 0.035), whereas no increase was observed following extended fast (0.140; p = 0.951). The difference in MCA-PSV values between the two meal states was not significant (6.672; p = 0.055).

Conclusion

Our results demonstrate possible diurnal variations in MCA-PI and UA-PI, with and without adjustment for fetal heart rate, that seem to be unaffected by maternal meal intake in healthy pregnancies.

The correlation between the cerebroplacental ratio and fetal arterial blood gas in appropriate-for-gestational-age fetuses: A cross-sectional study

Background

The cerebroplacental ratio (CPR) is an important index for predicting adverse pregnancy outcomes in small-for-gestational-age and appropriate-for-gestational-age fetuses.

Objective

To find out whether there is an association between the CPR level and the blood cord gases analysis in appropriate for gestational age fetuses.

Materials and Methods

This cross-sectional study included 347 pregnant women at the gestational age of 37-40 wk. Patients had an appropriate-for-gestational-age fetus confirmed from their first ultrasonography results. Participants were divided into two groups based on their CPR, measured before delivery. Finally, after delivery, arterial blood gas level and the incidence of emergency cesarean section, intrapartum fetal distress and neonatal intensive care unit admissions were compared between the two groups.

Results

Fifty-four (15.6%) cases had a CPR below the detection limit of the assay. The incidence of fetal distress, emergency cesarean section, neonatal hospitalization in the neonatal intensive care unit, and pH < 7.2 were significantly lower in women with CPR ≥ 0.67 multiples than in women with a CPR < 0.67 multiples of the median.

Conclusion

The third-trimester CPR is an independent predictor of stillbirth and perinatal mortality and morbidity. The role of UA/MCA Doppler and the CPR in assessing the risk of adverse pregnancy outcomes should be evaluated prospectively.

The role of abnormal cerebroplacental ratio in predicting adverse fetal outcome in pregnancies with scheduled induction of labor

OBJECTIVE

To investigate the role of abnormal cerebroplacental ratio (CPR) in predicting adverse fetal outcome in pregnancies with induction of labor.

METHODS

This prospective observational study conducted at Medeniyet University Göztepe Training and Research Hospital between December 1, 2018 and October 31, 2019 enrolled women with scheduled induction of labor at or beyond 37 weeks of pregnancy. Women with singleton non-anomalous fetuses with cephalic presentation and who had Bishop scores of 5 or less in pelvic examination were included in the study. Exclusion criteria were the presence of uterine scar history, non-cephalic presentation, multiple pregnancy, vacuum- or forceps-assisted delivery, and shoulder dystocia. Using fetal Doppler ultrasound, CPR was calculated (the ratio of umbilical artery to middle cerebral artery pulsatility index) and categorized into abnormal CPR (<1) and normal CPR (≥1). Data on maternal and delivery characteristics, fetal birth weight, and fetal complications were compared between the groups.

RESULTS

A total of 145 women were included, 28 in the abnormal CPR group and 117 in the normal CPR group. Multivariate analysis revealed labor induction at a later week of pregnancy (odds ratio [OR] 10.33, P = 0.001), lack of intrauterine growth restriction (IUGR) (OR 13.21, P = 0.001), fetal distress (OR 8.14, P = 0.003) or meconium aspiration (OR 159.91, P = 0.001), and umbilical artery pH values greater than 7.31 (OR 17.51, P = 0.015) to be associated with an increased likelihood of having normal (≥1) CPR values. Receiver operating characteristic analysis revealed association of normal CPR values with later labor induction (cut-off value of >38.3 weeks, P = 0.001), higher birth weight (cut-off value of >2460 g, P = 0.022) and higher umbilical artery pH (cut-off value of >7.31, P = 0.007).

CONCLUSION

Our findings revealed the significant role of abnormal CPR in predicting adverse fetal outcome in singleton pregnancies with scheduled induction of labor.

Intra- and Interobserver Reproducibility of Third Trimester Middle Cerebral Artery Pulsatility Index Measurement: A Prospective Cross-Sectional Study

BACKGROUND

Middle cerebral artery (MCA) pulsatility index (PI) Doppler in the third trimester of pregnancy is increasingly used.

OBJECTIVES

The aim of the study was to investigate intra- and interobserver reproducibility of MCA PI in the third trimester.

METHOD

Singleton pregnancies between 30+0 and 40+0 weeks were recruited. MCA Doppler velocimetry measurements were performed prospectively, independently, and blindly. Intra- and interobserver reproducibility was assessed by concordance correlation coefficient (CCC) and intraclass correlation coefficient (ICC); Bland-Altman plots were built, and limits of agreement (LoA) were calculated. Results were interpreted according to the cutoff set by the True Reproducibility of Ultrasound Techniques Review.

RESULTS

We enrolled 101 patients. ICCs for intraobserver reproducibility were 0.84 and 0.78 for raw values and percentiles, respectively; CCCs were 0.72 and 0.64. For interobserver reproducibility ICCs were 0.84 and 0.78, CCCs 0.72 and 0.63. According to the chosen criteria, these values show a poor-moderate reproducibility of third trimester MCA PI. Cohen's Kappa coefficients were 0.59 and 0.42, indicating a moderate agreement in discriminating normal and abnormal values.

CONCLUSIONS

Intra- and interobserver reproducibility of third trimester MCA PI, as assessed by ICC, CCC, and LoA, is far from satisfactory. This should be taken into account before taking clinical decisions.

Longitudinal growth assessment for prediction of adverse perinatal outcome in fetuses suspected to be small-for-gestational age

OBJECTIVE

Fetal growth restriction (FGR) is associated with an increased risk of adverse perinatal outcome. However, distinguishing this condition from small-for-gestational age (SGA) remains elusive. A set of criteria has been proposed recently for such a purpose, including the degree of smallness, Doppler parameters and growth velocity. The aim of this study was to establish whether the use of growth velocity adds value to Doppler assessment in predicting adverse perinatal outcome among SGA-suspected fetuses.

METHODS

This was a prospective cohort study of consecutive singleton pregnancies with late (diagnosis ≥ 32.0 weeks) SGA (estimated fetal weight (EFW) < 10^th centile). Longitudinal growth assessment was performed by calculation of EFW z-velocity between diagnosis and last scan before delivery. Improvement in the association with and predictive performance of EFW z-velocity for adverse perinatal outcome was compared against standard criteria of FGR evaluated before delivery (EFW < 3^rd centile, abnormal uterine Doppler or abnormal cerebroplacental ratio).

RESULT

A total of 472 patients were evaluated prospectively for suspected SGA. Of these, 231 (48.9%) qualified as late FGR. Univariate analysis showed a significant trend towards higher frequency (14.5% vs 8.2%; P = 0.041) of EFW z-velocity in the lowest decile in pregnancies with adverse perinatal outcome. Nonetheless, the addition of EFW z-velocity improved neither the association with nor the predictive performance of standard criteria of FGR for adverse perinatal outcome.

CONCLUSIONS

Longitudinal assessment of fetal growth by means of EFW z-velocity did not have any independent predictive value for adverse perinatal outcome when used in combination with Doppler in SGA-suspected fetuses. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Diagnosis and surveillance of late-onset fetal growth restriction

By consensus, late fetal growth restriction is that diagnosed >32 weeks. This condition is mildly associated with a higher risk of perinatal hypoxic events and suboptimal neurodevelopment. Histologically, it is characterized by the presence of uteroplacental vascular lesions (especially infarcts), although the incidence of such lesions is lower than in preterm fetal growth restriction. Screening procedures for fetal growth restriction need to identify small babies and then differentiate between those who are healthy and those who are pathologically small. First- or second-trimester screening strategies provide detection rates for late smallness for gestational age <50% for 10% of false positives. Compared to clinically indicated ultrasonography in the third trimester, universal screening triples the detection rate of late smallness for gestational age. As opposed to early third-trimester ultrasound, scanning late in pregnancy (around 37 weeks) increases the detection rate for birthweight <3rd centile. Contrary to early fetal growth restriction, umbilical artery Doppler velocimetry alone does not provide good differentiation between late smallness for gestational age and fetal growth restriction. A combination of biometric parameters (with severe smallness usually defined as estimated fetal weight or abdominal circumference <3rd centile) with Doppler criteria of placental insufficiency (either in the maternal [uterine Doppler] or fetal [cerebroplacental ratio] compartments) offers a classification tool that correlates with the risk for adverse perinatal outcome. There is no evidence that induction of late fetal growth restriction at term improves perinatal outcomes nor is it a cost-effective strategy, and it may increase neonatal admission when performed <38 weeks.

Is cerebroplacental ratio a marker of impaired fetal growth velocity and adverse pregnancy outcome?

BACKGROUND

The cerebroplacental ratio has been proposed as a marker of failure to reach growth potential near term. Low cerebroplacental ratio, regardless of the fetal size, is independently associated with the need for operative delivery for presumed fetal compromise and with neonatal unit admission at term.

OBJECTIVE

The main aim of this study was to evaluate whether the cerebroplacental ratio at term is a marker of reduced fetal growth rate. The secondary aim was to investigate the relationship between a low cerebroplacental ratio at term, reduced fetal growth velocity, and adverse pregnancy outcome.

STUDY DESIGN

This was a retrospective cohort study of singleton pregnancies in a tertiary referral center. The abdominal circumference was measured at 20-24 weeks' gestation and both abdominal circumference and fetal Dopplers recorded at or beyond 35 weeks, within 2 weeks of delivery. Abdominal circumference and birthweight values were converted into Z scores and centiles, respectively, and fetal Doppler parameters into multiples of median, adjusting for gestational age. Abdominal circumference growth velocity was quantified using the difference in the abdominal circumference Z score, comparing the scan at or beyond 35 weeks with the scan at 20-24 weeks. Both univariable and multivariable logistic regression analyses were performed to investigate the association between low cerebroplacental ratio and the low abdominal circumference growth velocity (in the lowest decile) and to identify and adjust for potential confounders. As a sensitivity analysis, we refitted the model excluding the data on pregnancies with small-for-gestational-age neonates.

RESULTS

The study included 7944 pregnancies. Low cerebroplacental ratio multiples of median was significantly associated with both low abdominal circumference growth velocity (adjusted odds ratio, 2.10; 95% confidence interval, 1.71-2.57, P <0.001) and small for gestational age (adjusted odds ratio, 3.60; 95% confidence interval, 3.04-4.25, P < .001). After the exclusion of pregnancies resulting in small-for-gestational-age neonates, a low cerebroplacental ratio multiples of the median remained significantly associated with both low abdominal circumference growth velocity (adjusted odds ratio, 1.76; 95% confidence interval, 1.34-2.30, P < .001) and birthweight centile (adjusted odds ratio, 0.99; 95% confidence interval, 0.998-0.995, P < .001). The need for operative delivery for fetal compromise was significantly associated with a low cerebroplacental ratio (adjusted odds ratio, 1.40; 95% confidence interval, 1.10-1.78, P = .006), even after adjusting for both the umbilical artery pulsatility index multiples of the median and middle cerebral artery pulsatility index multiples of median. The results were similar, even after the exclusion of pregnancies resulting in small-for-gestational-age neonates (adjusted odds ratio, 1.39; 95% confidence interval, 1.06-1.84, P = .018). Low cerebroplacental ratio multiples of the median remained significantly associated with the risk of operative delivery for presumed fetal compromise (P < .001), even after adjusting for the known antenatal and intrapartum risk factors. These associations persisted, even after the exclusion of small-for-gestational-age births. In appropriate-for-gestational-age-sized fetuses, abdominal circumference growth velocity was significantly lower in those with a low cerebroplacental ratio multiples of the median than in those with normal cerebroplacental ratio multiples of the median (P < .001).

CONCLUSION

The cerebroplacental ratio is a marker of impaired fetal growth velocity and adverse pregnancy outcome, even in fetuses whose size is considered appropriate using conventional biometry.