Fetal cerebral and umbilical Doppler in pregnancies complicated by late-onset placental abruption.

OBJECTIVE

To evaluate whether changes in the cerebroplacental Doppler and birth weight (BW) suggestive of chronic fetal hypoxemia, precede the development of late-onset placental abruption (PA) after 32 weeks.

METHODS

In a multicenter retrospective study, the Doppler examinations of the fetal umbilical artery (UA) and middle cerebral artery (MCA) recorded after 32 weeks were collected in pregnancies subsequently developing PA. The BW centiles were calculated and the MCA pulsatility indices (PI), and UA PI were converted into multiples of the median (MoM). Afterwards, a comparison was made with a group of fetuses, which did not develop PA. Logistic regression was used to adjust for potential confounders and evaluate the feasibility of the prediction model.

RESULTS

Pregnancies complicated by late-onset PA (n = 31) presented lower MCA PI (p = 0.015) and were smaller (p < 0.001) than those who did not (n = 1294). Logistic regression analysis indicated that cerebral vasodilation was more important than umbilical flow in the explanation of PA (MCA PI OR = 0.106, p = 0.014 and UA PI OR 1.901, p = 0.32). In addition, the influence of BW exerted was residual (BW centile OR = 0.989, p = 0.15).

CONCLUSIONS

Fetuses developing late-onset PA demonstrate significant cerebral vasodilation with scarce placental dysfunction, suggesting the existence of some kind of chronic hypoxemia that follows the late-onset pattern.