bioethics

Canadian research analysing more than 863,000 births over almost a decade, including 806 surrogacy deliveries, concluded that the risk of severe maternal morbidity was 7.8% in gestational carriers, more than three times the risk of conception without assisted reproductive techniques and almost twice the risk in IVF pregnancies. The three most frequent complications were severe postpartum haemorrhage, severe pre-eclampsia and puerperal sepsis. The study is published in the Annals of Internal Medicine.

A team of Chinese researchers report today in the journal Nature Communications the successful cloning of a rhesus monkey, with a healthy placenta, which survived for more than two years. According to the authors, this could improve the efficiency of the monkey cloning process, which so far is very low. Previously, different teams have cloned more mammalian species, including 'Dolly the sheep' and another species of macaque (Macaca fascicularis).

The Guardian newspaper reported on Wednesday that Magdalena Zernicka-Goetz's team had announced the generation of synthetic human embryos from stem cells at the annual meeting of the International Society for Stem Cell Research in Boston. The author later denied on Twitter that they were synthetic human embryos and spoke only of models, warning that it was pending publication in a scientific journal. The day after the publication in The Guardian, and as reported in El País, Jacob Hanna and his team published a preprint - a publication that has not been peer-reviewed - in bioRxiv on models of human embryos generated from stem cells without genetic editing. A few hours later, Zernicka-Goetz's team posted their preprint on bioRxiv.

The latest episode of competition between research groups working on the same topic, a very common situation in science, should not distract us from the actual achievement: synthetic human embryos, in the laboratory, made from stem cells, up to a post-implantation stage. Now, we must decide what status or condition we will grant to these synthetic embryos. Once again, science is leaping forward and testing the limits of the laws, posing new ethical challenges for us to solve. 

A US team has developed a non-invasive language decoder: a brain-computer interface that aims to reconstruct whole sentences from functional magnetic resonance imaging (fMRI). This is not the first attempt to create such a decoder; some of the existing ones are invasive - requiring neurosurgery; others are non-invasive, but only identify words or short phrases. In this case, as reported in the journal Nature Neuroscience, the team recorded brain responses - captured with fMRI - of three participants as they listened to 16 hours of stories. The authors used this data to train the model, which was then able to decode other fMRI data from the same person listening to new stories. The team argues that the model trained on one person's data does not decode another person's data well, suggesting that cooperation from the subject is required for the model to work properly.

Researchers in the United States have tested a new technique to select sperm and thereby increase the chances that the embryo will be of either sex. The proven efficacy is around 80 %. Although some countries such as the United States allow this type of procedure, in Spain it is prohibited except in cases of prevention of diseases linked to sex chromosomes. The authors of the article state that sperm selection is more ethically acceptable than embryo selection. The results are published in the journal PLOS ONE.

The variety of current dog breeds is the product of two centuries of human intervention, which has often selected characters for extravagance or supposed aesthetics. Lluís Montoliu, president of the CSIC Ethics Committee until last February, recalls that 15% of current dog breeds have some sort of more or less serious congenital disease.