Clinical application of fetal left modified myocardial performance index in the evaluation of fetal growth restriction

The role of interleukin-1 in perinatal inflammation and its impact on transitional circulation

Preterm birth is defined as delivery at <37 weeks of gestational age (GA) and exposes 15 million infants worldwide to serious early life diseases. Lowering the age of viability to 22 weeks GA entailed provision of intensive care to a greater number of extremely premature infants. Moreover, improved survival, especially at extremes of prematurity, comes with a rising incidence of early life diseases with short- and long-term sequelae. The transition from fetal to neonatal circulation is a substantial and complex physiologic adaptation, which normally happens rapidly and in an orderly sequence. Maternal chorioamnionitis or fetal growth restriction (FGR) are two common causes of preterm birth that are associated with impaired circulatory transition. Among many cytokines contributing to the pathogenesis of chorioamnionitis-related perinatal inflammatory diseases, the potent pro-inflammatory interleukin (IL)-1 has been shown to play a central role. The effects of utero-placental insufficiency-related FGR and in-utero hypoxia may also be mediated, in part, via the inflammatory cascade. In preclinical studies, blocking such inflammation, early and effectively, holds great promise for improving the transition of circulation. In this mini-review, we outline the mechanistic pathways leading to abnormalities in transitional circulation in chorioamnionitis and FGR. In addition, we explore the therapeutic potential of targeting IL-1 and its influence on perinatal transition in the context of chorioamnionitis and FGR.

Role of myocardial performance index (MPI) and cerebro-placental ratio (CPR) in predicting adverse perinatal outcome

INTRODUCTION

This study aimed to evaluate the association of the Myocardial Performance Index (MPI) and Cerebro-Placental Ratio (CPR) in predicting adverse perinatal outcomes in fetuses who are appropriately-grown (AGA), small-for-gestational-age (SGA) and growth restricted (FGR).

METHODS

Singleton pregnancies were recruited after 24 weeks. The patients were recruited after having been classified as AGA (AC/EFW > 10th centile), SGA (AC/EFW-3rd-10th centile without doppler abnormalities), and FGR (AC/EFW < 3rd centile or 3rd-10th centile with doppler abnormalities). A total of 103 cases comprising 48 AGA, 11 SGA, and 44 FGRfetuses were recruited. The Pulsatility Index of the Umbilical artery, Middle cerebral artery, Ductus Venosus, and Aortic Isthmus was obtained. MPI and CPR were calculated too. The primary outcome was to evaluate the predictive value of MPI and CPR for the composite adverse perinatal outcome.

RESULTS

The mean gestational age of recruitment was 30 weeks. The OR for Composite Adverse Perinatal Outcome in FGR group for MPI > .47 and CPR < 1.67 was 3.48 (95% CI: 1.00-12.24, p-value < .05) with sensitivity and specificity of 65% each and 11.08 (95% CI: 2.62-46.83, p-value = .001) with the sensitivity of 82% and specificity of 70%, respectively. When combined together, MPI and CPR yielded an OR of 58.5 (95% CI: 4.58-746.57, p-value = .002) with a sensitivity of 56.5% and specificity of 95% in the FGR group.

CONCLUSIONS

MPI in conjunction with CPR can be used together to predict adverse perinatal outcomes in FGR.

Fetal Cardiac Function: Myocardial Performance Index

The Myocardial Performance Index (MPI) or Tei index, presented by Tei in 1995, is the ratio of the sum of the duration of the isovolumetric contraction time (ICT) and isovolumetric relaxation time (IRT) to the duration of the ejection time (ET). The Modified Myocardial Performance Index (Mod-MPI), proposed in 2005, is considered a reliable and useful tool in the study of fetal heart function in several conditions, such as growth restriction, twin-twin transfusion syndrome, maternal diabetes, preeclampsia, intrahepatic cholestasis of pregnancy, and adverse perinatal outcomes. Nevertheless, clinical translation is currently limited by poorly standardised methodology as variations in the technique, machine settings, caliper placement, and specific training required can result in significantly different MPI values. This review aims to provide a survey of the relevant literature on MPI, present a strict methodology and technical considerations, and propose future research.

Feasibility of fetal left modified myocardial performance index in twin anemia polycythemia sequence and perinatal outcomes after antenatal intervention

OBJECTIVE

To evaluate the feasibility and clinical value of fetal left modified myocardial performance index (Mod-MPI) in assessment and management of prenatal twin anemia polycythemia sequence (TAPS).

METHODS

We retrospectively reviewed fetuses with TAPS diagnosed prenatally between 2015 and 2019 at Asan Medical Center. Doppler ultrasound evaluation including the peak systolic velocity (PSV) of the middle cerebral artery (MCA) and fetal echocardiography including left Mod-MPI were evaluated and followed up after antenatal management.

RESULTS

Among 10 cases of fetal twin pregnancies with prenatal TAPS, six were spontaneous and four were post-laser TAPS. Left Mod-MPI was abnormal in one or both twins of nine cases (90%) including all post-laser TAPS (n = 4) and 83.3% of spontaneous TAPS (n = 5). Three recipients, one donor and three former recipients/new donors had elevated left Mod-MPI values, and one donor, one recipient, two former donors/new recipients had decreased values. Antenatal intervention was performed in eight cases with intrauterine transfusion (n = 4), fetoscopic laser surgery (n = 2), radiofrequency ablation (n = 1), and intrauterine transfusion followed by radiofrequency ablation (n = 1). The remaining two cases were either delivered or managed expectantly. MCA-PSV and left Mod-MPI became normal on the follow-up scans in all cases except the delivered case. There were four fetal deaths: two occurred spontaneously and two were selectively terminated by radiofrequency ablation. Overall perinatal survival per fetus was 80% (16/20) and the median gestational age at delivery was 34.4 (range, 29.2-37.4) weeks. Neither postnatal death nor neurodevelopmental delay occurred during a median follow-up of 13 months (range, 0.25-60 months).

CONCLUSION

Fetal left Mod-MPI was useful for assessment of compromised fetal cardiac function in cases with prenatal TAPS. Application of fetal left Mod-MPI in prenatal staging of TAPS might help evaluate the severity of TAPS and decide timely antenatal intervention.

Fetal myocardial performance index in pregnancies with idiopathic mildly increased amniotic fluid volume

PURPOSE

To evaluate modified myocardial performance index (MPI), or Tei index, in fetuses of pregnancies with idiopathic mildly increased amniotic fluid index (AFI).

METHODS

We studied 25 cases (24-40 weeks) with idiopathic mildly increased AFI, and 25 gestational age- and fetal gender-matched healthy controls. Fetal echocardiographic variables and Doppler-derived indices were recorded, including left and right MPI, left isovolumetric contraction time (IVCT), left ejection time (ET), left isovolumetric relaxation time (IVRT), aortic and pulmonary arterial peak systolic velocity (PSV), left and right E/A ratios, middle cerebral artery (MCA) pulsatility index (PI), and umbilical artery (UA) PI.

RESULTS

The mean left MPI (0.52 vs 0.41, P < .0001) and right MPI (0.50 vs 0.42, P < .001) were higher, and mean IVCT (37.7 vs 25.9, P < .0001) was longer in cases than in controls. However, there were no significant differences between the two groups in IVRT (45.2 vs 43.2, P = .381), ET (160.2 vs 170.0, P = .079), aortic PSV (P = .073), left E/A (P = .080), pulmonary artery PSV (P = .061), right E/A (P = .054), MCA PI (P = .259), UA PI (P = .685), and cerebroplacental ratio (P = .645).

CONCLUSION

Pregnancies with idiopathic mildly increased AFI were associated with a significant increase in the fetal MPI of both left and right ventricles.

Utility of the modified myocardial performance index in growth-restricted fetuses

OBJECTIVES

The modified myocardial performance index (Mod-MPI) can be used to assess myocardial function. Fetal growth restriction can affect fetal myocardial function, thereby altering the Mod-MPI. The results of previous studies on the utility of the Mod-MPI in growth-restricted fetuses are conflicting. The aim of this study was to calculate the left modified-MPI in growth-restricted fetuses and to compare the results with those of healthy fetuses.

METHODS

This was a prospective cross-sectional case-control study. In total, 40 women with growth-restricted fetuses and 40 women with fetuses of normal weight (controls) at 29-39 gestational weeks were enrolled in the study. An experienced obstetrician calculated the Mod-MPI for each fetus. Women with systemic diseases or fetuses with chromosomal/structural abnormalities were excluded from the study. The results of Mod-MPI measurements of the two groups were compared.

RESULTS

The mean single deepest vertical pocket (SDVP) of amniotic fluid, estimated fetal weight (EFW), and isovolumetric relaxation time (IRT) was significantly lower in the fetal growth restriction (FGR) group as compared with these parameters in the control group (P < .05). The uterine artery (UtA) pulsatility index (PI) was significantly higher in the FGR group as compared with that in the control group (P < .05). There were six cases of absent end-diastolic flow (AED) in the FGR group. There were no statistically significant between-group differences in the Mod-MPI, isovolumetric contraction time (ICT), and ejection time (ET) (P > .05). There was also no statistically significant correlation between the Mod-MPI in the fetuses with AED and the control group for Mod-MPI (P > .05).

CONCLUSION

The utility of the Mod-MPI in FGR remains unclear. Future studies with larger populations are needed to determine the utility of the Mod-MPI as a predictor of cardiac compromise in FGR.

Assessment of fetal modified myocardial performance index in early-onset and late-onset fetal growth restriction

Aim

To investigate the changes of modified myocardial performance index (Mod‐MPI) in early‐onset and late‐onset fetal growth restriction (FGR) cases, and its association with adverse perinatal outcome.

Methods

This was a prospective study on 77 early‐onset and 100 late‐onset FGR cases. Hundred normal fetuses were matched as control groups for early‐onset and late‐onset FGR groups, respectively. Mod‐MPI and vessel Doppler parameters including umbilical artery (UA), ductus venosus (DV), and middle cerebral artery (MCA) were measured. Perinatal outcomes were followed up. Mod‐MPI of FGR cases were compared in normal Doppler, abnormal Doppler, and control groups. The association of Mod‐MPI and perinatal outcome was investigated, and further efficacy of Mod‐MPI predicting adverse outcome was studied.

Results

Compared with control groups, both abnormal and normal Doppler groups showed increased Mod‐MPI in early‐onset and late‐onset FGR, respectively. Mod‐MPI had no significant difference between abnormal and normal Doppler groups. Mod‐MPI was associated with adverse outcome in early‐onset FGR (OR = 3.307) and late‐onset FGR (OR = 3.412). The sensitivity and specificity of Mod‐MPI predicting adverse outcome were 60% and 80% when cutoff value was 0.47 in early‐onset FGR. And they were 65% and 70% when cutoff value was 0.50 in late‐onset FGR.

Conclusion

Fetal growth restriction fetuses had increased Mod‐MPI. Mod‐MPI could be used to predict adverse perinatal outcome of FGR fetuses. Mod‐MPI was an effective parameter to supplement vessels’ Doppler parameters in monitoring FGR.

Assessment of the Cardiac Function in Intrauterine Growth-Restricted Fetuses and Appropriate for Gestational Age Fetuses

Aim

Aim of the study is to evaluate the myocardial performance index in intrauterine growth restricted fetuses and compare this index with appropriate for gestational age fetuses.

Materials & Methods

A prospective study was conducted in S.M.S Medical College Jaipur, involving 72 singleton fetuses ≥ 28 weeks of gestation divided into two groups: 36 intrauterine growth restricted fetuses (IUGR) and 36 appropriate for gestational age fetuses (AGA). Myocardial performance index was obtained by fetal echocardiography.

Results

The mean myocardial performance index in the IUGR fetuses and AGA fetuses was statistically significant and that was 0.62 ± 0.02 and 0.45 ± 0.01, respectively; (p value: < 0.0001). These findings suggest that IUGR induces primary cardiac changes, which could explain the increased predisposition to cardiovascular disease in adult life. This study concluded that Fetal echocardiographic parameters (MPI) identify a high risk group within the IUGR fetuses, which could be targeted for early screening of blood pressure and other cardiovascular risk factors, as well as for promoting a healthy diet and physical exercise.

Fetal myocardial performance index in assessment and management of small-for-gestational-age fetus: a cohort and nested case-control study

OBJECTIVE

To assess the clinical utility of the fetal myocardial performance index (MPI) in assessment and management of the small-for-gestational-age (SGA) fetus/growth-restricted fetus (FGR).

METHODS

This was a prospective cohort study in metropolitan Australia of patients referred in the period June 2012 to March 2015 to fetal medicine services at 24-38 weeks' gestation for suspected singleton SGA/FGR (estimated fetal weight (EFW) < 10^th centile with or without abnormal umbilical artery (UA) Doppler) pregnancy. Patients had MPI assessed in addition to routine measures, and were followed through to birth. We compared MPI values against those of a local reference population and gestational age-matched controls, and assessed the correlation with perinatal outcome and other Doppler measures.

RESULTS

Fifty-two cases were included, 38 diagnosed < 32 weeks and 14 diagnosed ≥ 32 weeks. None demonstrated significantly elevated left, right or delta MPI compared with the reference population or with gestational age-matched controls at the time of first MPI evaluation. There were no consistent longitudinal patterns in MPI that would suggest its clinical utility. The mean ± SD gestational age at delivery was 34.6 ± 3.8 weeks and birth weight was 1.7 ± 0.6 kg, and the median neonatal hospital admission time was 27 days, confirming a pathological cohort. There were no significant correlations between left, right or delta-MPI and perinatal outcome, although there were significant correlations between UA, middle cerebral artery (MCA) and ductus venosus (DV) Doppler and perinatal outcome (birth weight, gestational age at birth and length of neonatal hospital stay). Exploratory subgroup comparisons (EFW < 3^rd vs 3^rd -10^th centile; early- vs late-onset; abnormal vs normal UA Doppler) found only minor differences in MPI, reaching statistical, but not clinical, significance, only in the EFW < 3^rd vs 3^rd -10^th centile comparison.

CONCLUSIONS

MPI did not demonstrate clinical utility in either triage or longitudinal follow-up of an SGA/FGR cohort presenting to fetal medicine services. Given that prior research suggesting its utility originates from single-center cohorts, while multicenter, large cohorts have suggested little utility or no additional utility if routine UA/MCA/DV Doppler is performed, publication bias may have affected previous reports. It seems unlikely that MPI has clinical utility in assessment and management of SGA/FGR fetuses. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Can the Myocardial Performance Index Be Used as a New Predictive Factor for a Poor Prognosis in Fetuses With Idiopathic Polyhydramnios?

OBJECTIVES

The purpose of this study was to determine whether there are any changes in cardiac function in fetuses with idiopathic polyhydramnios and also to evaluate the value of the myocardial performance index for prediction of adverse perinatal outcomes.

METHODS

A prospective case-control study was conducted with a total of 134 fetuses between 24 and 40 weeks' gestation. Polyhydramnios was defined as an amniotic fluid index of greater than 24 cm. Seventy-three fetuses of healthy mothers were assigned as the control group whereas 36 fetuses with an amniotic fluid index of 24 to 34 cm constituted the nonsevere polyhydramnios group, and 31 fetuses with an amniotic fluid index of 35 cm or greater constituted the severe polyhydramnios group. Fetal echocardiography was performed to compare cardiac function parameters among groups. To determine which perinatal outcomes were independently associated with an increased myocardial performance index, a multivariate logistic regression analysis was performed.

RESULTS

The myocardial performance index was significantly higher in polyhydramnios groups compared with controls (P < .001). Among fetuses with polyhydramnios, the myocardial performance index was significantly higher in severe polyhydramnios compared with nonsevere polyhydramnios (P = .003). An increased myocardial performance index in polyhydramnios was independently associated with nonreassuring fetal status (odds ratio, 2.12; 95% confidence interval, 1.41-4.53; P = .005), emergency cesarean delivery (odds ratio, 1.54; 95% confidence interval, 1.12-2.37; P= .025), and respiratory distress syndrome (odds ratio, 1.79; 95% confidence interval, 1.21-3.87; P = .012).

CONCLUSIONS

An increased myocardial performance index is an early indicator of adverse perinatal outcomes in pregnancies complicated by idiopathic polyhydramnios.

Fetal myocardial index during labor

BACKGROUND: The Myocardial Performance Index (MPI) is a Doppler derived myocardial function tool and can be used to evaluate systolic and diastolic function in fetuses. The objectives of this study were to investigate the MPI during labor and compare it to values in non-laboring women.

METHODOLOGY: 40 women with uncomplicated, term, singleton pregnancies were recruited to this prospective observational study at Thomas Jefferson University Hospital. Controls were a retrospective cohort of women > 34 weeks who underwent third trimester fetal echocardiography. Fetal left and right sided isovolumic contraction time, isovolumic relaxation time and ejection time were recorded before, during and after contractions. Right and left sided MPI was then calculated.

RESULTS: Laboring patients and non-laboring patients were comparable for age, race, gravidity and parity. During labor the average left MPI was 0.63 ± 0.17 and the average right MPI was 0.62 ± 0.20. The coefficient of correlation between MPI and cervical dilation was 0.15 for left MPI Index and 0.14 for right MPI. When comparing non-laboring to laboring women, the average left MPI for non-laboring women was 0.34 ± 0.04, p = <0.001.

CONCLUSIONS: Myocardial Performance Index is a non-invasive, easily attainable measure of cardiac function that can be obtained during labor and does not change with cervical dilation. MPI is significantly different between laboring and non-laboring women. The fetal MPI may help define fetal status in labor.

Intrauterine growth restriction: impact on cardiovascular development and function throughout infancy

Intrauterine growth restriction (IUGR) refers to the situation where a fetus does not grow according to its genetic growth potential. One of the main causes of IUGR is uteroplacental vascular insufficiency. Under these circumstances of chronic oxygen and nutrient deprivation, the growth-restricted fetus often displays typical circulatory changes, which in part represent adaptations to the suboptimal intrauterine environment. These fetal adaptations aim to preserve oxygen and nutrient supply to vital organs such as the brain, the heart, and the adrenals. These prenatal circulatory adaptations are thought to lead to an altered development of the cardiovascular system and "program" the fetus for life long cardiovascular morbidities. In this review, we discuss the alterations to cardiovascular structure, function, and control that have been observed in growth-restricted fetuses, neonates, and infants following uteroplacental vascular insufficiency. We also discuss the current knowledge on early life surveillance and interventions to prevent progression into chronic disease.

Fetal left ventricular myocardial performance index: Defining normal values for Indian population and a review of literature

Objective:

The aim of this study was to determine normal values for fetal left ventricular (LV)-myocardial performance index (MPI) in Indian population and to assess its relation to advancing gestation and fetal heart rate (FHR).

Materials and Methods:

Two hundred pregnant women without any pregnancy-related complications and whose fetuses were shown to have structurally normal hearts were enrolled in this study. Doppler waveform involving simultaneous display of mitral inflow and LV outflow was obtained in all. Various intervals including isovolumetric contraction time (IVCT), isovolumetric relaxation time (IVRT), and ejection time (ET) were measured and then the MPI was calculated using the formula IVCT + IVRT/ET. Also the correlation between MPI and gestation age and FHR was assessed. We also reviewed the literature on the use of MPI for the assessment of fetal LV function.

Results:

The normal MPI in second and third trimester fetuses of Indian population was 0.42 ± 0.03. The mean IVCT was 33 ± 4 milliseconds (ms), mean IVRT was 39 ± 5 ms, and mean ET was 169 ± 9 ms. The mean heart rate was 148 ± 8 bpm and the mean PR interval was 111 ± 10 ms. There was no significant association of LV-MPI with either FHR or advancing gestation.

Conclusion:

MPI is a useful parameter for the assessment global cardiac function. MPI has the advantage of not being affected by FHR, ventricular size, and geometry or image quality. The review of literature shows its significant importance in monitoring complicated pregnancies.