Critical umbilical artery Doppler abnormalities in early fetal growth restriction and the timing of delivery: an overestimated clinical challenge in daily obstetric practice?
Year: 2014
Type: letter
Abstract: The Perinatal Ireland Research Consortium comprises seven major obstetric centers in Ireland, with a total delivery rate in excess of 50 000 births per year. Between January 2010 and June 2012, the PORTO Study (Prospective Observational Trial to Optimize Pediatric Health in Intrauterine Growth Restriction), a prospective observational (and initially randomized) trial recruited 1116 non-anomalous singleton growth-restricted fetuses below the 10th centile for gestation1, 2. Similar to the TRUFFLE trial (Trial of Umbilical and Fetal Flow in Europe) (ISRCTN56204499)3, a subset of 400 pregnancies with critically abnormal umbilical artery Doppler measurements (namely, absent end-diastolic flow), were to undergo randomization to delivery for either: (i) abnormal computerized cardiotocography; or (ii) abnormal ductus venosus flow. The randomized arm of the study was stopped after 12 months of recruitment due to the lack of cases eligible for randomization. Even in the largest centers, with a birth rate over 8500/year, only a maximum of 14 such cases were identified on an annual basis, with approximately half requiring delivery for non-fetal-related causes. Relating our data to those of the TRUFFLE study, which had a recruitment window between 26 and 32 weeks, 416 of the 1116 fetuses in our study were recruited in this gestational period; of these, 132 (32%) had abnormal umbilical artery Doppler (pulsatility index > 95th centile), with a subset of 31 (8%) developing absent or reversed end-diastolic flow (AEDF). The median time from recruitment to delivery for those with AEDF was 6 days. While it is highly impressive that Lees and colleagues randomized such a large number of pregnancies affected by intrauterine growth restriction (IUGR), our experience reflects the challenges that they also faced in recruiting their patients. The TRUFFLE trial took 5 years to recruit 500 patients in 20 European centers (5 patients/year/center). Recently, TRUFFLE reported on perinatal morbidity and mortality outcomes4 with the main results still to come. The question remains as to whether this trial will give us ‘real answers’ to real questions, given that this problem is heterogeneous, complex and encountered relatively rarely in daily obstetric practice, even in large tertiary units. In addition, PORTO data2 suggest that there is not one predominant pathway but that there are in fact many possible sequential pathways of Doppler deterioration in IUGR, questioning the usefulness of multivessel Doppler assessment to inform frequency of surveillance and timing of delivery of IUGR fetuses. Furthermore, the TRUFFLE trial excluded all cases of severe early-onset IUGR before 26 weeks and with estimated fetal weight below 500 g, which, in our opinion, poses a significant management dilemma, given that 24 weeks' gestation is now commonly used to define viability in many centers internationally. We agree that the optimal management of severe early IUGR is challenging, but in real terms we found this to be a relatively rare clinical problem, even in the largest clinical centers that recruited to the PORTO Study. The fundamental issues in IUGR which require urgent resolution are international agreement on terminology and definition of disease prior to suggesting optimal surveillance strategies and issuing delivery recommendations. J. Unterscheider*, S. Daly, K. O'Donoghue and F. D. Malone, for the Perinatal Ireland Research Consortium Department of Obstetrics and Gynecology, Royal College of Surgeons in Ireland, Rotunda Hospital, Dublin, Ireland *Correspondence. (e-mail: [email protected])
DOI: 10.1002/uog.13266
Institution: Royal College of Surgeons in Ireland
Language: English
Subfield: Obstetrics and Gynecology
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W2055215199