Objective: To assess the correlation of Myocardial Performance Index (MPI), Doppler ultrasound indices of fetal blood vessels with perinatal mortality and early neonatal morbidity in small-for-gestational age (SGA) fetuses.

Materials and Methods: The cross-sectional study of singleton pregnancies with small for gestational age fetuses with perinatal mortality and early neonatal morbidity was conducted from March 1st to November 30th, 2014. Forty-nine cases of singleton pregnancies with SGA fetuses were enrolled by excluding chromosome abnormality, major organ anomaly or intrauterine infection. MPI, Doppler ultrasonography of umbilical artery, middle cerebral artery, aortic isthmus, ductus venosus and umbilical vein were performed within 48 hours before delivery. The Z-scores were calculated for Doppler indices. The delivery method and the indication of delivery, data regarding perinatal mortality, bronchopulmonary dysplasia (BPD), interventricular hemorrhage (IVH) and necrotizing enterocolitis (NEC) were recorded. The correlation and multiple logistic regression analyses was used to find the significant factors of perinatal mortality and early neonatal morbidity in SGA fetuses.

Results: Total 38 pregnant women and newborns were analyzed. No perinatal mortality was detected but found some of early neonatal morbidity. 6 newborns needed to admit in NICU (15.8%), 3 of which had BPD (7.9%). Neither IVH nor NEC was detected. This study did not demonstrate the correlation between MPI, all Doppler parameters after dichotomous branching and early neonatal morbidity, with individual adjusted R2 = -0.027 (p-value= 0.951) for UA S/D ratio ≥ 95th percentile, -0.005 (p-value= 0.819) for UA PI ≥ 95th percentile, 0.091 (p-value=0.368) for cerebroplacental ratio ≤ 1.08, 0.088 (p-value= 0.996) for aortic isthmus flow index ≤ 5th percentile, 0.160 (p-value= 0.058) for MPI ≥ 95th percentile. Only, the gestational age (GA <38 wks) was the only significant factor associated with early neonatal morbidity with adjusted R2 of 0.620 (p-value <0.05, Odd ratios 7.0, 95%CI: 0.61-79.87).

Conclusion: There was no significant correlation between perinatal mortality and early neonatal morbidity in small-for-gestational age (SGA) fetuses with Doppler ultrasound parameters in terms of MPI, UA S/D ratio, UA pulsatility index, MCA pulsatility index, DV waveform, aortic isthmus flow index and UV waveform in SGA fetuses. Gestation age was the most significant associated factor with early neonatal morbidity in SGA fetuses. However, no conclusion could be drawn regarding the correlation of perinatal mortality with MPI and Doppler ultrasound parameters due the lack of fetal and neonatal death.

Keywords: Myocardial performance index, MPI, Doppler ultrasound, Venous Doppler, Perinatal mortality, Early neonatal morbidity, SGA