Significance of Velamentous Cord Insertion for Twin-Twin Transfusion Syndrome.
BACKGROUND
The objective of this study was to evaluate the actual association between velamentous cord insertion (VCI) and twin-twin transfusion syndrome (TTTS) in the native cohort concerning the natural history of monochorionic twin pregnancies.


METHODS
All monochorionic diamniotic twin pregnancies who received prenatal care from <16 weeks of gestation until delivery at our center between 2004 and 2013 were included in this retrospective cohort study. Macroscopically defined cord insertion site was recorded as velamentous, marginal, or central. The effects of VCI on TTTS and a composite of adverse outcomes, including abortion, death, and neurological morbidities ≤28 days of age, were evaluated with a multiple logistic regression model.


RESULTS
A total of 357 monochorionic diamniotic twin pregnancies were analyzed. VCI in both twins was noted in 2.5% of cases and VCI in at least one twin was noted in 22.1% of cases. The incidence of TTTS was 8.4%; the incidence of a composite of adverse outcomes in at least one twin was 9.8%. There was no correlation between VCI and TTTS as well as a composite of adverse outcomes.


CONCLUSIONS
VCI in monochorionic twin pregnancies was not a risk factor for TTTS and severe perinatal morbidities.
Department of Maternal Fetal Medicine, Osaka Medical Center and Research Institute for Maternal and Child Health, Izumi, Japan.
Naoto
N
Yonetani
Keisuke
K
Ishii
Hiroshi
H
Kawamura
Aki
A
Mabuchi
Shusaku
S
Hayashi
Nobuaki
N
Mitsuda
D000328:Adult; D005260:Female; D005330:Fetofetal Transfusion / Q000150:complications* / Q000473:pathology; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D015999:Multivariate Analysis; D016017:Odds Ratio; D010920:Placenta / Q000473:pathology; D010922:Placenta Diseases / Q000473:pathology*; D011247:Pregnancy; D059285:Pregnancy, Twin; D012189:Retrospective Studies; D014470:Umbilical Cord / Q000473:pathology