Abnormal Middle Cerebral Artery Doppler Associates with Spontaneous Preterm Birth in Normally Grown Fetuses

Abstract

Objective: Our aim was to evaluate whether Doppler changes in the fetal middle cerebral (MCA) and umbilical arteries (UA) suggesting fetal hypoxemia precede the onset of spontaneous preterm birth (PTB). Methods: We studied 2,340 appropriate-for-gestational-age singleton pregnancies that had MCA and UA pulsatility indices (PI) recorded at 28-32 weeks. Values including the cerebroplacental ratio (CPR) were converted into multiples of the median and evaluated according to both gestational age at the onset of labor and the interval between ultrasound and labor. ROC analysis was used to calculate the ability in the prediction of spontaneous PTB before 32, 34 and 37 weeks' gestation. Results: While no correlations were observed for the UA PI and CPR, lower MCA PI values were associated with an earlier onset of labor (p < 0.001) and a shorter ultrasound-labor interval (p = 0.028). The ROC analysis at different gestational ages and intervals to labor indicated that MCA PI values were poorly predictive of spontaneous PTB (all areas under the curve <0.7). Conclusions: Low MCA PI values at 28-32 weeks are associated with subsequent spontaneous PTB, indicating that fetal hypoxemia unrelated with placental disease might be implicated in the onset of labor. This association, however, is unlikely to be useful in the prediction of PTB.

The risk of preterm birth associated with a low cerebroplacental ratio

“…We also found that in the cohort with a low CPR that delivered within 2 weeks, there was an increased prevalence of hypertension as well as an increased rate of IOL. However, in contrast to other publications [9] our results indicate that there is no increased risk of spontaneous preterm birth in the low CPR cohort. Consistent with other publications [1,12,13] we found an increased risk of emergency caesarean section for fetal compromise as well as poorer neonatal outcomes in this group.…”

“…The association between cerebral redistribution and/or a low CPR and preterm birth is confounded by the fact that many studies have included fetuses with growth restriction in their study cohorts which often confounds the results because of the higher rate of iatrogenic preterm delivery. Furthermore the evidence for an association between a low CPR and spontaneous preterm birth is very limited with only a small number of studies published in this area [9][10][11].…”

Modifiable risk factors for spontaneous preterm birth in nulliparous women: a prospective study

“…Thus, specific characteristics of the infertile population or the type of the provided fertility treatment may have increased the risk of sPTB [16]. Other theories include mild abnormalities of placental function or chronic placental inflammation as possible risk factors for sPTB in ART pregnancies, as those women are at higher risk for placental insufficiency [17,18].…”

Risk of spontaneous preterm birth in singleton pregnancies conceived after IVF/ICSI treatment: meta‐analysis of cohort studies

“…Blastocyst transfer is also associated with increased nuchal translucency measurement, likely due to delays in embryogenesis or placentation 36 . Mild abnormalities of placental function leading to fetal hypoxemia or chronic placental inflammation may contribute to sPTB, particularly in the IVF/ICSI group, in which patients are at a higher risk of placental insufficiency 37,38 . In fresh embryo cycles, the risk of placental dysfunction is higher and our results showed a consistently higher risk for sPTB in this subgroup (Figure 3b).…”