Early detection of reversed diastolic umbilical flow: should we offer karyotyping?

Doppler Ultrasound of the Umbilical Artery: Clinical Application

OBJECTIVE

 To provide a survey of relevant literature on umbilical artery Doppler ultrasound use in clinical practice, technical considerations and limitations, and future perspectives.

METHODS

 Literature searches were conducted in PubMed and Medline, restricted to articles written in English. Additionally, the references of all analyzed studies were searched to obtain necessary information.

RESULTS

 The use of this technique as a routine surveillance method is only recommended for high-risk pregnancies with impaired placentation. Meta-analyses of randomized trials have established that obstetric management guided by umbilical artery Doppler findings can improve perinatal mortality and morbidity. The values of the indices of Umbilical artery Doppler decrease with advancing gestational age; however, a lack of consensus on reference ranges prevails.

CONCLUSION

 Important clinical decisions are based on the information obtained with umbilical artery Doppler ultrasound. Future efforts in research are imperative to overcome the current limitations of the technique.

Reversed end-diastolic flow in the umbilical artery at 10-14 weeks of gestation is associated with absent pulmonary valve syndrome

OBJECTIVE

To determine the incidence of reversed end-diastolic flow (REDF) in the umbilical artery in high-risk first-trimester pregnancies and evaluate associated conditions.

METHODS

This was a prospective evaluation of the umbilical artery Doppler waveforms of 614 consecutive high-risk pregnancies between 10 and 14 weeks of gestation, to determine those with REDF. The associated anomalies and characteristics of these fetuses were then investigated.

RESULTS

In 278/614 (45.3%) fetuses, there was positive end-diastolic flow in the umbilical artery; in 331/614 (53.9%) end-diastolic flow was absent and in 5/614 (0.8%) there was REDF. Three of the five fetuses with REDF had tetralogy of Fallot (TOF) with absent pulmonary valve syndrome (APVS) and a patent ductus arteriosus, and all three showed signs of cardiac failure, with reversed blood flow in the ductus venosus during atrial systole and generalized skin edema. Another fetus had a large ventricular septal defect and the remaining fetus had agenesis of the ductus venosus. Three fetuses had trisomy 18 and one had trisomy 13.

CONCLUSIONS

REDF in the umbilical artery is very rare in early pregnancy and mostly occurs in association with major fetal vascular anomalies and cardiac defects, particularly TOF with APVS and patent arterial duct. We propose that the patency of the arterial duct in TOF with APVS leads to heart failure with subsequent demise early in pregnancy. Therefore, the frequent absence of the arterial duct observed in APVS in later pregnancy is more likely to be a result of early selection than a prerequisite for the development of this lesion as has been proposed previously.

First-trimester reversed end-diastolic flow in the umbilical artery is not always an ominous sign

We report five cases of first-trimester reversed end-diastolic flow in the umbilical artery. Diagnoses were performed between 8 and 12 gestational weeks. All but one case appeared as a transient early finding. Second-trimester fetal demise occurred in two cases. One case delivered at 32 weeks with severe growth restriction but recovered well. The other two cases had a good pregnancy outcome. Our experience suggests that this early Doppler finding is not always an ominous sign.

Reversed end-diastolic flow in first-trimester umbilical artery: an ominous new sign for fetal outcome

OBJECTIVE

The purpose of this study was to assess the fetal outcome of first-trimester pregnancies with reversed end-diastolic flow in the umbilical artery.

STUDY DESIGN

Doppler studies in the umbilical artery were carried out in 2970 consecutive pregnancies scanned at 10 to 14 weeks.

RESULTS

We observed 11 (0.4%) cases of reversed end-diastolic flow. Of these, an autosomal trisomy was shown in 7 and a congenital heart defect in 2 additional fetuses. Fetal demise was observed in 5 pregnancies, neonatal death was observed in 1, and termination of pregnancy was carried out in 4. Only 1 fetus survived.

CONCLUSIONS

Reversed end-diastolic flow in first-trimester umbilical artery signals an ominous prognosis even with normal karyotype.

Sonographic findings of the umbilical cord: implications for the risk of fetal chromosomal anomalies

In this review we summarize current knowledge on sonographic findings of the umbilical cord and the risk they impose for chromosomal abnormalities of the fetus. A Medline search of the literature was performed and the pertinent English-language literature was reviewed. Anatomical and Doppler abnormalities of the umbilical cord may be associated with an increased risk of chromosomal aberrations in the fetus. Therefore, level II prenatal sonography should also include a careful examination of the umbilical cord.

Are color and pulsed Doppler sonography safe in early pregnancy?

Diagnostic ultrasound has been used for many years with a remarkable history of safety during the standard clinical practice. Introduction of color and pulsed Doppler modes resulted with higher levels of transmitted and absorbed ultrasonic energy. This fact raised the question for the safety of its use in early pregnancy. This article presents the pros and contras regarding the safety and summarized actual guidelines and safety limits suggested and prescribed by several instances that supervise the use of ultrasound in medicine (WFUMB, ECMUS, ECURS, AIUM/NEMA). In addition, different clinical and experimental applications of Doppler ultrasound in early pregnancy are discussed regarding the safety limits. Generally, there are no strictly defined limits for the use of Doppler ultrasound in the early pregnancy. However, there is an unequivocal demand for carefulness that is best expressed by the ALARA principle. The prudent use of Doppler takes into account benefits against the possible theoretical risks, rather than prohibiting clinically useful technology or applications.