New Delhi: The scientists, led by Erasmus MC, University Medical Center, Rotterdam, The Netherlands, studied embryo development using imaging technology in a total of 611 ongoing pregnancies, which included 33 pregnancies ending in miscarriage. To create 3D holograms of embryos, virtual reality techniques were employed. The study is published in the journal Human Reproduction.
The scientists assessed the overall development of the embryo, including arms and legs, the shape and length of the brain and the curvature of the embryo. They also measured the embryonic volume and the distance between the crown of the head and the bottom of the embryo's buttocks, or the crown-rump length.
"We found that in the first ten weeks of the pregnancy, embryos in pregnancies that end in a miscarriage took four days longer to develop than babies that did not miscarry. We also found that the longer it takes for an embryo to develop, the more likely it is to miscarry," said lead researcher Melek Rousian, a gynaecologist at Erasmus MC.
"This would enable health professionals to provide counselling to women and their partners about the prospective outcome of the pregnancy and the timely identification of a miscarriage," said Rousian. The researchers collected data from women taking part in the ongoing Rotterdam Periconceptional Cohort (PREDICT study), a prospective study embedded in patient care in the department of obstetrics and gynaecology at Erasmus MC.
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Women were recruited to the study between 2010 and 2018 when they were between seven and ten weeks pregnant, the study said. Embryo morphology, or the internal and external characteristics and measurements of an embryo, was studied against the established stages of embryo development, called the Carnegie Stages. "The 3D virtual reality technology makes it much easier to see the development of the arms and legs. In the Carnegie staging system, the curvature and position of the arms and legs have an important role," said first author Carsten Pietersma, Erasmus MC.
The researchers found that compared to an ongoing pregnancy, a pregnancy ending in a miscarriage was associated with a lower Carnegie stage, indicating a slower rate of development. The Carnegie stages of embryonic development cover the first ten weeks of gestation and run from 1 to 23. The study further found that the embryo would reach the final Carnegie stage four days later than an embryo from a pregnancy resulting in a healthy baby and that a delay in Carnegie stage increased the likelihood of a miscarriage by 1.5 per cent per delayed stage.
A shorter crown-rump length and smaller embryonic volume too were found to contribute to a pregnancy ending in miscarriage, when the researchers used foetal growth and birth weight to study development following the tenth week, as there was no staging system after that. "We are able to show a significant association between miscarriage and a delay in the early development of the embryo, even if the miscarriage was after ten weeks of gestation," said Pietersma. The study acknowledged that the relatively smaller number of miscarriages studied may not be representative of the general population. (PTI)
