Only time will tell. The idea is that one day, scientists might be able to take regular cells – maybe skin or blood cells – from two same-sex parents, use gene-editing to turn them into stem cells (which can develop into any cell type in the body), and then coax these stem cells into becoming sex cells. Cells from one partner – male or female – could be used to make eggs, while cells from the other male or female partner could be used to make sperm. Then in vitro fertilisation (IVF) could be used to make a baby.
In October 2018, Chinese scientists revealed that they’d performed a similar procedure in mice, and created mouse pups from same-sex parents. The same month, scientists from Japan announced that they’d made human eggs from blood cells.
The prospect of human babies from same-sex parents had moved a step closer, but the studies also highlighted just how difficult the procedure is likely to be. The human eggs were difficult to grow and didn’t mature properly, and although healthy mouse pups could be made from two mothers, pups with two fathers died shortly after birth.
In addition, the stem cells used to make the mice had to be genetically modified in order to give the mouse embryos the best chance of survival (the same would have to be done with human same-sex babies). Despite this, out of 210 embryos created, only 29 survived. For the foreseeable future at least, the stakes are too high, and the process too unpredictable, to consider using on humans.