TY - JOUR
T1 - Hypothesis acardiac twin pregnancies
T2 - Pathophysiology-based hypotheses suggest risk prediction by pump/acardiac umbilical venous diameter ratios
AU - van Gemert, Martin J C
AU - Pistorius, Lourens R.
AU - Benirschke, Kurt
AU - Bonsel, Gouke J.
AU - Vandenbussche, Frank P H A
AU - Paarlberg, K. Marieke
AU - van den Wijngaard, Jeroen P H M
AU - Nikkels, Peter G J
PY - 2016/2/1
Y1 - 2016/2/1
N2 - BACKGROUND: A total of 75% of monozygotic twins share 1 monochorionic placenta where placental anastomoses cause several serious complications, for example, acardiac twinning. Acardiac twins lack cardiac function but grow by perfusion of arterial blood from the pump twin. This rare pregnancy has 50% natural pump twin mortality but accurate risk prediction is currently impossible. Recent guidelines suggest prophylactic surgery before 18 weeks, suggesting 50% unnecessary interventions. We hypothesize that (1) adverse pump twin outcome relates to easy-to-measure pump/acardiac umbilical venous diameter (UVD) ratios, representing acardiac perfusion by the pump's excess cardiac output. This hypothesis suggests that (2) UVD-ratios are large, mildly varying in cases without complications but small and decreasing when complications develop, thus predicting that (3) UVD-ratios may allow risk prediction of pump twins. In this exploratory clinical pilot, we tested whether UVD-ratio measurements support these predictions. METHODS: We included 7 uncomplicated (expectant management), 3 elective surgical, and 17 complicated cases (pump decompensation, emergency intervention/delivery or demise). Nine UVD-ratios were measured sonographycally and 18 by pathology. RESULTS: Uncomplicated cases have larger, two serial measurements showing mildly varying UVD-ratios; elective surgical cases show larger UVD-ratios; complicated cases have smaller, two serial measurements showing decreasing UVD-ratios. There were no false-positives, no false-negatives and noncrossing linear trendlines of uncomplicated and complicated cohorts. CONCLUSION: Our data provide first evidence that UVD-ratios allow risk prediction of pump twins. More early uncomplicated and late complicated cases are needed, for example, in a prospective trial, before the separation between uncomplicated and complicated cohorts is accurate enough to support a well-founded decision on (early) intervention.
AB - BACKGROUND: A total of 75% of monozygotic twins share 1 monochorionic placenta where placental anastomoses cause several serious complications, for example, acardiac twinning. Acardiac twins lack cardiac function but grow by perfusion of arterial blood from the pump twin. This rare pregnancy has 50% natural pump twin mortality but accurate risk prediction is currently impossible. Recent guidelines suggest prophylactic surgery before 18 weeks, suggesting 50% unnecessary interventions. We hypothesize that (1) adverse pump twin outcome relates to easy-to-measure pump/acardiac umbilical venous diameter (UVD) ratios, representing acardiac perfusion by the pump's excess cardiac output. This hypothesis suggests that (2) UVD-ratios are large, mildly varying in cases without complications but small and decreasing when complications develop, thus predicting that (3) UVD-ratios may allow risk prediction of pump twins. In this exploratory clinical pilot, we tested whether UVD-ratio measurements support these predictions. METHODS: We included 7 uncomplicated (expectant management), 3 elective surgical, and 17 complicated cases (pump decompensation, emergency intervention/delivery or demise). Nine UVD-ratios were measured sonographycally and 18 by pathology. RESULTS: Uncomplicated cases have larger, two serial measurements showing mildly varying UVD-ratios; elective surgical cases show larger UVD-ratios; complicated cases have smaller, two serial measurements showing decreasing UVD-ratios. There were no false-positives, no false-negatives and noncrossing linear trendlines of uncomplicated and complicated cohorts. CONCLUSION: Our data provide first evidence that UVD-ratios allow risk prediction of pump twins. More early uncomplicated and late complicated cases are needed, for example, in a prospective trial, before the separation between uncomplicated and complicated cohorts is accurate enough to support a well-founded decision on (early) intervention.
KW - Acardiac twin pregnancy
KW - Pathophysiology
KW - Risk prediction of pump twin
KW - Serial UVD-ratio measurement
KW - Twin reversed-arterial perfusion sequence
KW - Umbilical venous diameter ratio (UVD-ratio)
UR - http://www.scopus.com/inward/record.url?scp=84983212545&partnerID=8YFLogxK
U2 - 10.1002/bdra.23467
DO - 10.1002/bdra.23467
M3 - Article
C2 - 26689996
AN - SCOPUS:84983212545
SN - 1542-0752
VL - 106
SP - 114
EP - 121
JO - Birth Defects Research Part A - Clinical and Molecular Teratology
JF - Birth Defects Research Part A - Clinical and Molecular Teratology
IS - 2
ER -