Middle cerebral artery blood flow in the fetus and central nervous system complications in the neonate

Doppler study of the fetal vertebral artery in small for gestational age fetuses with intrauterine growth restriction

OBJECTIVES

The purposes of this study were to evaluate the Doppler resistive index of the fetal vertebral artery in small for gestational age (SGA) fetuses and to examine the ability of the vertebral artery resistive index in the diagnosis of intrauterine growth restriction (IUGR).

METHODS

A total of 437 Doppler examinations of the vertebral and umbilical artery resistive indices were performed in 437 fetuses between 26 and 41 weeks' gestation. According to birth weight, fetuses were classified into 5 groups: 1, above the 10th percentile; 2, between the 10th and 5th percentiles; 3, between the 5th and 3rd percentiles; 4, below the 3rd percentile; and 5, below the 3rd percentile with an umbilical artery resistive index above the 95th percentile. Subsequently, vertebral artery resistive index values were converted into multiples of the median, and box and whisker charts were generated to evaluate differences. Finally, receiver operating characteristic curves were calculated to assess the accuracy of the vertebral artery resistive index for predicting IUGR and a low Apgar score.

RESULTS

Compared to normally grown fetuses, vertebral artery resistive index values were lower in fetuses with birth weight below the 3rd percentile, and this difference was greater in fetuses with birth weight below the 3rd percentile and Doppler anomalies of the umbilical artery. The receiver operating characteristic analysis showed that the vertebral artery resistive index diagnosed SGA fetuses and low Apgar scores poorly. However, it performed better in cases of severe IUGR with high umbilical artery resistive index values.

CONCLUSIONS

Preliminary data show that the vertebral artery resistive index diminishes in growth-restricted SGA fetuses. Doppler examination of the vertebral artery seems to identify a group of fetuses with brain sparing and severe IUGR.

Relations between fetal brain-sparing circulation, oxytocin challenge test, mode of delivery and fetal outcome in growth-restricted term fetuses

OBJECTIVE

The study was designed as a prospective non-interventional, observational study to elucidate the potential value of fetal middle cerebral artery Doppler velocimetry to identify brain-sparing flow in a surveillance program for suspected intrauterine growth restriction (IUGR).

MATERIAL AND METHODS

The study was carried out at Skåne University Hospital, Malmö, Sweden. One hundred and twenty-six single pregnancies suspected of IUGR at ≥36 gestational weeks were assessed. The main outcome measures were positive/negative oxytocin challenge test (OCT) and cesarean/vaginal delivery. The pregnancies were managed with ultrasound fetometry, uterine and umbilical artery Doppler flow velocimetry, nonstress test, and an OCT to decide the optimal time and mode of delivery. Cases with a positive OCT were promptly delivered by cesarean section, whereas negative cases were allowed a trial of labor. Middle cerebral artery Doppler flow velocimetry results were blinded to the managing obstetricians. Brain-sparing flow was defined as a middle cerebral artery-to-umbilical artery pulsatility index ratio of <1.08. Nonparametric statistics with significance set at p < 0.05 were used, and Cohen's kappa coefficient was calculated for congruence of brain-sparing flow with OCT and mode of delivery, respectively.

RESULTS

The positive predictive value and sensitivity figures of brain-sparing flow to indicate a positive OCT and cesarean delivery were 33-63%. The inter-rater reliability of brain-sparing flow vs. positive OCT showed a kappa coefficient of 0.19, and brain-sparing flow vs. cesarean section among OCT-negative cases a kappa coefficient of 0.23.

CONCLUSION

Fetal brain-sparing flow is a poor predictor of a positive OCT, and of cesarean section in OCT-negative cases.

Management of fetal growth restriction

When fetuses are growth restricted as a result of inadequate placental function, there is an increased risk of poor perinatal outcome compared with fetuses where small dimensions are constitutional and associated with normal placental function. The management of reduced fetal size should therefore focus on the identification of the fetus at risk due to placental dysfunction, and longitudinal assessment to reduce the morbidity and mortality associated with this pathology by ideal timing of delivery. The aim of this review is to rationalize the best way to assess fetuses affected in this way and how to improve their outcome by appropriately timed intervention.

Focal Cerebral Infarction in Newborn: Description of Three Cases

We observed 3 full-term newborns with focal ischemic injury of the middle cerebral artery (MCA), in which diagnosis of MCA stroke was suspected by US and confirmed by CT scan and MRI. A four-year follow-up was carried out to study the effect of neonatal stroke on neurodevelopmental outcome. All children had a history of pre-perinatal risk factors: neonatal cerebral infarction in term infants, in fact, has many possible causes, including bacterial meningitis, inherited or acquired coagulopathies, trauma and hypoxia-ischemia. The prognosis of neonatal MCA infarction depends on early diagnosis, on the CNS plasticity mechanism and, finally, on medical therapy and neuropsychological rehabilitation.