Modeling gestational age centiles for fetal umbilicocerebral ratio by quantile regression analysis: a secondary analysis of a prospective cross-sectional study

Maternal cardiovascular function in the prediction of fetal distress in labor: a prospective cohort study

OBJECTIVE

To explore the strength of association and the diagnostic accuracy of maternal hemodynamic parameters detected noninvasively in predicting an adverse perinatal outcome in labor.

METHODS

Prospective cohort study of singleton women undergoing antepartum care at 37-39 weeks of gestation. A noninvasive ultrasonic cardiac output monitor (USCOM®) was used for cardiovascular assessment. The study outcome was a composite score of adverse perinatal outcome, which included at least one of the following variables: Cesarean or instrumental delivery for abnormal fetal heart monitoring, umbilical artery pH <7.10 or admission to neonatal special care unit. Attending clinicians were blinded to maternal cardiovascular indices. Multivariate logistic regression and area under the curve (AUC) analyses were used to test the diagnostic accuracy of different maternal and ultrasound characteristics in predicting adverse perinatal outcome.

RESULTS

A total of 133 women were recruited. The rate of adverse perinatal outcome was 25.6% (34/133). Women who delivered without abnormal perinatal outcome (controls) were more likely to be parous, compared to those who had an adverse perinatal outcome (44.4 vs. 73.5%; p = .005). Control women had significantly lower systemic vascular resistance (SVR) (median, 1166 vs. 1352 dynes × s/cm⁵, p = .023) and SVR index (SVRI) (median, 2168 vs. 2627 dynes × s/cm⁵/m², p = .039) compared to women who had an adverse perinatal outcome. In this latter group the prevalence of SV <50 ml was significantly higher than in the control group (38.2% (13/34) vs. 11.1%, (11/99) p = .0012). At multivariable logistic regression analysis, SVR (aOR 1.307; 95% CI 1.112-2.23), SV <50 ml (aOR 4.70; 95% CI 1.336-12.006) and parity (3.90: 95% CI 1.545-10.334) were the only variables independently associated with adverse perinatal outcome. A model considering only SVR showed an AUC of 0.631. Integration of SVR with SV <50 ml and parity significantly improves the diagnostic performance of SVR alone to predict adverse outcome (AUC 0.732; p = .016).

CONCLUSION

Pre-labor modifications of maternal cardiovascular variables are associated with adverse perinatal outcome. However, their predictive accuracy for perinatal compromise is low, and thus their use as standalone screening test for adverse perinatal outcome in singleton pregnancies at term is not supported.

Administration of antenatal corticosteroid is associated with reduced fetal growth velocity: a longitudinal study

OBJECTIVE

To elucidate whether antenatal administration of corticosteroids in pregnancies with threatened preterm labor affects growth velocity.

METHODS

A cohort of 262 pregnancies exposed to antenatal corticosteroids longitudinally studied and delivered from 36 weeks (cases) were compared to an unexposed group of 270 women (controls).

METHODS

Fetal growth was assessed analyzing the growth velocity of head circumference (HC), abdominal circumference (AC), femur length (FL) and estimated fetal weight (EFW). Growth velocity (GV) was calculated as the difference in the Z-score between the biometric measurements recorded at the time of steroids administration and at 36 week of gestation, divided by the time interval (expressed in days) between the two scans and multiplied by 100. Similarly, changes in the Pulsatility Index (PI) of uterine, umbilical (UA), middle cerebral (MCA) arteries and cerebroplacental ratio (CPR) during the same time interval were also computed.

RESULTS

Median gestational age at steroid administration (30.2 weeks vs 30.4) and follow-up ultrasound (36.4 weeks vs 36.4) were similar between cases and controls. In pregnancies exposed to antenatal corticosteroids, growth velocity in the HC (-0.61 vs. 0.12; p ≤ 0.001), AC (-0.55 vs. -0.04; p ≤ 0.001) and EFW (-0.89 vs. 0.06; p ≤ 0.001) were lower when compared to pregnancies not exposed to steroid therapy, while there was no difference in the growth velocity of FL (-0.05 vs 0.19; p = .06) or in any of the Doppler parameters explored.

CONCLUSION

In pregnancies exposed to antenatal steroid therapy, there is a significant reduction in fetal growth velocity not otherwise associated with changes in cerebroplacental Dopplers.