A tiny rhino foetus developed by IVF: Jon A Juárez’s best photograph

Only two female northern white rhinos are left - but neither can carry a pregnancy. So a surrogate was used. Tragically, the foetus didn't reach full term

This photograph captures a moment of fragile hope: the world's first IVF rhino pregnancy, a tiny foetus that reignited optimism among scientists fighting to save the northern white rhino from extinction. There are only two female northern white rhinos left on the planet - Najin and her daughter Fatu. Neither can carry a pregnancy due to health complications. The last male died in 2018 and that makes the species functionally extinct.

For the past 15 years, the BioRescue Project - an international consortium dedicated to saving the species - has been collecting and preserving sperm from deceased males. Using this genetic material and egg cells from Fatu, they've created 38 embryos. It may sound like a lot, but it's not. Since Najin and Fatu cannot carry a pregnancy, surrogate mothers are essential and it was decided to use southern white rhinos, a less endangered subspecies. The team also needed to prove that their technique would work with southern white rhino embryos before transferring any of the northern white rhino embryos into a surrogate.

After 13 attempts to transfer an embryo they achieved the first viable IVF pregnancy in a southern white rhino. The foetus in this image is the result after transfer. Tragically, the pregnancy didn't reach full term (16-18 months), as the surrogate mother died from a bacterial infection at 70 days. But the pregnancy demonstrated that the technique is viable - a critical milestone.