The prediction of fetal compromise and acidosis by biophysical profile scoring in the small for gestational age fetus

Cerebroplacental ratio as a predictor of intrapartum fetal compromise in term pregnancy

OBJECTIVE

To predict intrapartum fetal compromise (FC) and admission to neonatal intensive care unit (NICU) by cerebroplacental ratio (CPR) in term pregnancies.

METHODS

A prospective observational study recruited women with singleton, term pregnancies. Ultrasound (US) was done for fetal biometry, umbilical and middle cerebral artery (UA, MCA) Doppler parameters, and CPR calculated. Intrapartum variables and neonatal data were recorded.

RESULTS

Mean interval from US to delivery was 2.21 ± 2.71 days. Rate of operative delivery for FC was 17.47%. Multivariate logistic regression analysis showed that UA pulsatility index (PI) multiples of median (MoM) (P = 0.001), MCA PI MoM (P = 0.001), and CPR MoM (P = 0.001) were significantly and independently associated with operative delivery for FC. Similarly, UA PI MoM (P = 0.004), MCA PI MoM (P = 0.009), and CPR MoM (P = 0.003) were also significantly and independently associated with admission to the NICU. Rate of operative delivery for presumed FC was higher in approprate-for-gestational-age fetuses with low CPR than in small-for-gestational-age fetuses with normal CPR (43.1% and 37.5%, respectively).

CONCLUSION

Lower mean CPR and CPR MoM were independently associated with the need for operative delivery for presumed FC and NICU admission at term. CPR is more likely to be associated with FC due to placental insufficiency than birth weight.

(1)H MRS: a potential biomarker of in utero placental function

The placenta is a temporary organ that is essential for a healthy pregnancy. It performs several important functions, including the transport of nutrients, the removal of waste products and the metabolism of certain substances. Placental disorders have been found to account for over 50% of stillbirths. Despite this, there are currently no methods available to directly and non-invasively assess placental function in utero. The primary aim of this pilot study was to investigate the use of (1)H MRS for this purpose. (1)H MRS offers the possibility to detect several placental metabolites, including choline, lipids and the amino acids glutamine and glutamate (Glx), which are vital to fetal development and placental function. Here, in utero placental spectra were acquired from nine small for gestational age (SGA) pregnancies, a cohort who are at increased risk of perinatal morbidity and mortality, and from nine healthy gestation-matched pregnancies. All subjects were between 26 and 39 weeks of gestation. Placenta Glx, choline and lipids at 1.3 and 0.9 ppm were quantified as amplitude ratios to that of intrinsic H2O. Wilcoxon signed rank tests indicated a significant difference in Glx/H2O (p = 0.024) between the two groups, but not in choline/H2O (p = 0.722) or in either lipid/H2O ratio (1.3 ppm, p = 0.813; 0.9 ppm, p = 0.058). This study has demonstrated that (1)H MRS has potential for the detection of placental metabolites in utero. This warrants further investigation as a tool for the monitoring of placental function.

Intrauterine growth restriction: how to manage and when to deliver

Intrauterine growth restriction secondary to placental insufficiency is a major cause of perinatal morbidity and mortality in the United States. Once intrauterine growth restriction is identified, obstetrical management is focused on assuring safety while the fetus continues to mature within a potentially hostile intrauterine environment. In the United States, the approach to management and delivery of the premature growth-restricted fetus is often based on serial biophysical profile evaluations, whereas in Europe it is usually based on the results of cardiotocography. However, there is no single test that seems superior to the other available tests for timing the delivery of the growth-restricted fetus. Therefore, the decision to deliver a fetus, especially at <32 weeks, remains mostly on the basis of empirical management.