[A PROPOSAL FOR CHANGING THE PROTOCOL FOR ANATOMICAL SCANS IN TWIN PREGNANCIES IN ISRAEL FOLLOWING OUR EXPERIENCE IN THE PROSPECTIVE EVALUATION AND CLINICAL MANAGEMENT OF TWIN PREGNANCIES].

INTRODUCTION

Twin pregnancies are associated with a high incidence of fetal structural and genetic malformations. Early detection will improve pregnancy outcomes and offer early intervention when necessary.

METHODS

A prospective, observational study in twin pregnancies, including multiple sonographic scans at different gestational ages to identify fetal structural anomalies.

RESULTS

We enrolled 120 women (240 fetuses) with di- or mono-chorionic live twins. All fetuses had an anomaly scan performed in the first, early (13+6-17+6gestational weeks), second, and third trimester. A total of 15 significant structural anomalies were identified. Five anomalies (33%) were identified in the first trimester, another 5 cases (33%) were identified in the early scan, an additional 3 (20%) at the second-trimester scan, and finally, two more (12.3%) were identified in the third-trimester scan. A total of 6 fetuses demised spontaneously. Four fetuses were reduced. Two women (4 fetuses) left the study. Altogether, 216 fetuses were delivered, and no anomaly was identified post-partum.

CONCLUSIONS

In twin pregnancies, the unification of the nuchal and the early anomaly scan in the first trimester and the performance of the second and third-trimester scans will result in the identification of most fetal malformations without added cost. We recommend the performance of three anomaly scans, one in each trimester. Our conclusion should be confirmed in a larger cohort.

DISCUSSION: Over 86% of significant prenatal structural anomalies were identified until the midst of pregnancy. A model of three complete anomaly scans, one in every trimester, is proposed. Our experience allowed us to identify all the anomalies at a similar cost to the current model of four scans (including first-trimester NT and third-trimester weight assessment).