Zygosity Misclassification of Recent Young Twins by Maternal Reports in Japan
Department of Health Science, Ishikawa Prefectural Nursing University, Ishikawa, Japan
- Corresponding Author:
- Syuichi Ooki
Department of Health Science
Ishikawa Prefectural Nursing University
E-mail: [email protected]
Received date: April 26, 2017; Accepted date: April 28, 2017; Published date: April 30, 2017
Citation: Ooki S (2017) Zygosity Misclassification of Recent Young Twins by Maternal Reports in Japan. J Preg Child Health 4:318. doi:10.4172/2376-127X.1000318
Copyright: © 2017 Ooki S. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution and reproduction in any medium, provided the original author and source are credited.
The problem of zygosity misclassification of twins has been paid little attention in Japan. By analyzing maternal reports collected using an internet questionnaire, the author found that around 30% of monozygotic twins were misclassified as dizygotic twins, mainly by obstetricians. On the other hand, the percentage of dizygotic twin pairs misclassified as monozygotic twins was lower. Misclassification was more frequently observed in cases of spontaneous pregnancy compared to iatrogenic pregnancy. The percentage of monozygotic twins misclassified as dizygotic is in very good accordance with that of monozygotic twins having two placentas. The reported number of placentas was very strongly associated with the reported zygosity. Thus, many monozygotic twins in Japan were still misclassified as dizygotic by obstetricians, presumably based solely on the placental findings.