Consensus protocol for management of early and late twin-twin transfusion syndrome: Delphi study

OBJECTIVE

Fetoscopic laser photocoagulation (FLP) is a well-established treatment for twin-twin transfusion syndrome (TTTS) between 16 and 26 weeks' gestation. High-quality evidence and guidelines regarding the optimal clinical management of very early (prior to 16 weeks), early (between 16 and 18 weeks) and late (after 26 weeks) TTTS are lacking. The aim of this study was to construct a structured expert-based clinical consensus for the management of early and late TTTS.

METHODS

A Delphi procedure was conducted among an international panel of experts. Participants were chosen based on their clinical expertise, affiliation and relevant publications. A four-round Delphi survey was conducted using an online platform and responses were collected anonymously. In the first round, a core group of experts was asked to answer open-ended questions regarding the indications, timing and modes of treatment for early and late TTTS. In the second and third rounds, participants were asked to grade each statement on a Likert scale (1, completely disagree; 5, completely agree) and to add any suggestions or modifications. At the end of each round, the median score for each statement was calculated. Statements with a median grade of 5 without suggestions for change were accepted as the consensus. Statements with a median grade of 3 or less were excluded from the Delphi process. Statements with a median grade of 4 were modified according to suggestions and reconsidered in the next round. In the last round, participants were asked to agree or disagree with the statements, and those with more than 70% agreement without suggestions for change were considered the consensus.

RESULTS

A total of 122 experts met the inclusion criteria and were invited to participate, of whom 53 (43.4%) agreed to take part in the study. Of those, 75.5% completed all four rounds. A consensus on the optimal management of early and late TTTS was obtained. FLP can be offered as early as 15 weeks' gestation for selected cases, and can be considered up to 28 weeks. Between 16 and 18 weeks, management should be tailored according to Doppler findings.

CONCLUSIONS

A consensus-based treatment protocol for early and late TTTS was agreed upon by a panel of experts. This protocol should be modified at the discretion of the operator, according to their experience and the specific demands of each case. This should advance the quality of future studies, guide clinical practice and improve patient care. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Single uterine axial fast acquisition magnetic resonance fetal survey: is it feasible?

OBJECTIVES

To determine which non-biometric components of the ultrasound fetal survey can routinely be seen on a single fast acquisition magnetic resonance (MR) sequence aligned axial to the maternal uterus.

STUDY DESIGN

The non-biometric components of the routine fetal ultrasound examination were applied retrospectively to the initial MR single-shot fast spin-echo acquisition aligned axial to the maternal uterus in the normal fetus to determine whether these parameters could be routinely evaluated. Nineteen women with anatomically normal fetuses had a total of 31 MR studies performed for fetal or maternal indications, either as part of an indicated examination or as part of a study protocol approved by the institutional review board. The images in these 31 MR studies were reviewed by two independent examiners who were blinded to the other's assessment; concordance was necessary for a component to be adequately assessed. The Wilcoxon rank sum test was used to determine the effect of gestational age and fetal lie on the ability to assess non-biometric parameters.

RESULTS

Assessment was possible in 85% of the non-biometric parameters. Cord insertion, external genitalia and the four-chamber view of the heart were most problematic. In only two cases was the four-chamber view of the heart identified. Longitudinal lie allowed significantly more parameters (82%) to be evaluated than transverse lie (45%) (p < 0.003). No difference based on gestational age was found.

CONCLUSION

A single fast acquisition axial MR sequence can evaluate 85% of the non-biometric components of the fetal ultrasound survey. Fetal lie is an important confounder in the ability to resolve fetal anatomy with a single MR axial uterine acquisition.