Determining if same-sex twins are identical or non-identical (from one egg or two; monozygotic or dizygotic) is not always straight forward, say the researchers. They looked at data from the Gemini study, a birth cohort of 2402 families with twins born in England and Wales in 2007.
Parents of same sex twins (1586) were asked if they knew whether their twins were identical or not and how they discovered that information.
The majority of parents (1302/82%) reported that they had been given the information by health professionals based on the formation of the placenta as seen on the prenatal scan. Of this group, as part of the Gemini data collection, all parents completed a validated zygosity questionnaire[i] when their twins were on average 8.2 months old. This questionnaire asks about the children's height, eye colour, hair colour and overall confusability and has been found in a previous study to correctly assign zygosity in 95% of cases.
The researchers found that out of the 1302 parents, 191 (14.7%) were misinformed about their same sex twins' zygosity (identical or non-identical).
In addition, 38% of parents said they were told after an antenatal scan that their twins shared a placenta and were therefore identical while 62% of parents were told their twins were non identical as they had two placentas.
However 25-30% of identical twins can have two placentas say the researchers. If the zygote splits within two days of fertilisation, separate placentas develop.
Jane Wardle, Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London and co-author of the commentary paper said:
"Finding out if your twins are identical or not is important to parents. However our data suggests that there may be a lack of knowledge among some health professionals about both identical and non identical twins having two placentas.
"Parents have the right to the relevant information if it is available. However most parents will understand that it is not always possible to give a specific answer."
John Thorp, BJOG Deputy-Editor-in-Chief added:
"This paper highlights the uncertainty that can exist in finding out whether same sex twins are identical or not. Additional training may be required for health professionals to avoid giving out the wrong information to parents."
1] Price TS, Freeman B, Craig I, Petrill SA, Ebersole L, Plomin R. Infant zygosity can be assigned by parental report questionnaire data. Twin Res 2000;3:129-133.
Amputees can learn to control a robotic arm with their minds
28.11.2017 | University of Chicago Medical Center
The importance of biodiversity in forests could increase due to climate change
17.11.2017 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig
MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.
Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...
Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
12.12.2017 | Physics and Astronomy
12.12.2017 | Earth Sciences
12.12.2017 | Power and Electrical Engineering