Researchers from the Ozanne group, working in collaboration with the Giussani lab (Dept. Physiology, Development and Neuroscience) have found that exposing rat fetuses to hypoxia (low oxygen levels) during development led to advanced ageing of ovaries and fewer eggs available in female offspring. The team found a decrease in the number of ovarian follicles in exposed pups and that telomeres were shorter in ovarian tissue (used as a proxy for ageing).
Hypoxia in the womb is already known to have potential long-term effects on the cardio-metabolic health of the offspring but this study is the first time it has been shown to affect fertility.
“It’s as if low levels of oxygen whilst in utero caused the female offspring’s ovarian tissue to age faster after birth,” says first author Catherine Aiken (MRL and Dept. of Obstetrics and Gynaecology). “Biologically, the tissue appears older and the female would run out of eggs – in other words, become infertile – at a younger age.”
Hypoxia can be caused by factors including smoking, pre-eclampsia, maternal obesity, and living at high altitude.
“Now that we’ve seen a link between hypoxia and fertility problems in rats, we know what to look for in women,” says Aiken. “If the same turns out to be true for them, then women at risk will be able to take action: for example, by having children earlier in life.”
Aiken et al. Chronic gestational hypoxia accelerates ovarian ageing and lowers ovarian reserve in next-generation adult rats. FASEB; 27 March 2019; DOI: 10.1096/fj.201802772R