New Markers for Placental Dysfunction at Term – Potential for More

Abstract

The remaining placental reserve capacity at term plays a decisive role in the perinatal morbidity of mother and child. Considering advances made in the field of fetal monitoring, the routine examination methods currently used at term or late term may be insufficient to detect subclinical placental dysfunction (PD). The aim of this study is to offer an up-to-date, narrative review of the literature in the context of detecting PD at term using complementary ultrasound markers and biomarkers. Parameters of fetomaternal Doppler ultrasound and fetal cardiac function, as well as (anti-)angiogenic factors in maternal serum are potential PD markers. These may help identify patients that may benefit from an elective, early induction of labor at term, thereby potentially reducing morbidity and mortality. However, their value in terms of the optimal date of delivery must first be determined in randomized controlled trials on a large number of cases.

Role of the cerebro-placental-uterine ratio in predicting adverse perinatal outcome in low-risk pregnancies at term

“…Uterine contractions during labor and the subsequent compression of the uterine arteries physiologically reduces the uteroplacental perfusion by up to 60% [ 25 ]. Hence, the antenatal placental function is crucial when it comes to the adequate fetal response to this physiological stress situation [ 12 ].…”

“…Looking at the progress made in the field of fetal monitoring, the examination methods (evaluation of fetal heart rate patterns, measuring amniotic fluid volume, estimating fetal weight) routinely used at full (39 + 0–40 + 6) or late (41 + 0–41 + 6) term [ 26 ] may be insufficient to detect subclinical PD [ 12 ]. Accordingly, the systematic investigation of established and novel Doppler indices in full and late term is important, although our results show a comparatively low predictive power of the CPUR regarding CAPO and OD for IFC.…”

“…Accordingly, the systematic investigation of established and novel Doppler indices in full and late term is important, although our results show a comparatively low predictive power of the CPUR regarding CAPO and OD for IFC. Recent data concerning the role of feto-maternal Doppler ultrasound in low-risk pregnancies and its association with APO, raise the question of whether abnormal Doppler indices, especially in the late-term situation (41 + 0–41 + 6), can or even should be cause for the recommendation of labor induction (not only an offer [ 16 ]) at 41 + 0 weeks of gestation (even in the case of normal amniotic fluid volume and CTG as well as an proven AGA-fetus) [ 12 ]. This is to be seen in particular against the background of the data of large randomized controlled trials on perinatal morbidity and mortality after induction of labor in the full and late-term period (vs. expectant management) [ 21 , 22 ].…”

“…Similarly, recent published data on the role of uterine Doppler in low-risk term pregnancies in early labor showed an association between raised mUtA-PI with an higher incidence of obstetric intervention due to fetal distress [ 11 ]. Hence, a Doppler parameter combining all these information from the uterine, placental, and fetal vessels could potentially improve detection of subclinical placental dysfunction (PD) at term compared to CPR even more [ 12 ].…”

Cerebroplacental versus Umbilicocerebral Ratio—Analyzing the Predictive Value Regarding Adverse Perinatal Outcomes in Low- and High-Risk Fetuses at Term

“…Due to poor prediction using the CPR, it was proposed to inverse the ratio into the umbilicocerebral ratio (UCR). The UCR was considered to improve the prediction of unfavorable outcomes as this ratio increases with cerebral vasodilatation and increased umbilical resistance, while the CPR approaches zero [ 12 , 13 ]. To date, there is an ongoing debate about the benefit of the UCR compared to the CPR.…”