Perinatal outcomes in twin pregnancies with discordant Doppler velocimetric findings

Hemodynamic Changes in Umbilical Artery and Middle Cerebral Artery With Oligohydramnios in Third Trimester of Pregnancy

Objective:

The objective of this study was to determine the hemodynamic changes in the umbilical artery (UA) and middle cerebral artery (MCA) with oligohydramnios, during third trimester of pregnancy.

Materials and Methods:

A cross-sectional descriptive study was done in a perinatal ultrasound center, over a 9-month period. The participant sample size was 64, and all of the women were conveniently consented and selected for the study. All individuals were referred for obstetrical sonography in the third trimester, with oligohydramnios. All fetal anomalies, such as a neural tube defect, dwarfism, an abdominal wall defect, were excluded from the study.

Results:

The mean systolic to diastolic (S/D) ratio for the UA was 3.01, within a range of 1.49 to 5.60 (± 0.79 SD). The mean pulsatility index (PI), of the UA, was 1.11, within a range of 0.41 to 5.51 cm (± 0.64 SD). The mean resistive index (RI) of the UA was 0.66, within a range of 0.33 to 1.25 cm (± 0.13 SD). The mean S/D ratio of the MCA was 5.68, within a range of 2.05 to 26.10 (± 3.10 SD). The mean PI of the MCA was 1.67 within a range of 0.75 to 2.55 cm (± 0.45 SD). The mean resistive index (RI), of the UA, was 0.82 within a range of 0.51 to 1.77 cm (± 0.82 SD).

Conclusion:

The Doppler indices may rise as pregnancy advances, especially in fetuses with oligohydramnios. In these types of patients, the flow within the MCA may decrease, with an increase in the gestational age. Consequently, it appears that oligohydramnios may lead to vascular remodeling of the UA and MCA.

Selective IUGR in dichorionic twins: what can Doppler assessment and growth discordancy say about neonatal outcomes?

OBJECTIVE

The aim of the present study was to assess, in a population of dichorionic twin pregnancies with selective growth restriction, the effect of inter-twin differences by use of Doppler velocimetry and fetal growth discordancy on perinatal outcomes.

METHODS

This was a retrospective study including dichorionic twin pregnancies from January 2008 to December 2015 at the Department of Obstetrics and Gynecology of Fondazione MBBM. Only dichorionic twin pregnancies affected by selective intrauterine growth restriction (IUGR) delivering at ≥24 weeks were included in the study.

RESULTS

We found that twin pregnancies with inter-twin estimated fetal weight (EFW) discordance ≥15% were significantly associated with a higher risk of preterm delivery before 32 (P=0.004) and 34 weeks (P=0.04). Similarly, twin pregnancies with inter-twin abdominal circumference (AC) discordance ≥30° centiles were associated with a higher rate of neonatal intensive care unit (NICU) admission (P=0.02), neonatal resuscitation (P=0.02) and adverse neonatal composite outcome (P=0.04). Of interest, when comparing twin pregnancies according to Doppler study, growth restricted twins had a higher rate of composite neonatal outcome and in multivariate analysis, an abnormal Doppler was an independent risk factor for this outcome.

CONCLUSIONS

Our study associated growth discrepancy with specific pregnancy outcomes, according to defined cut-offs. In addition, we demonstrated that an abnormal umbilical artery Doppler is independently associated with a composite neonatal adverse outcome in growth restricted fetuses.