NAD in the placenta sets when labour starts
Why does labour begin when it does? The answer turned out to lie in a molecule familiar from ageing research: NAD.
NAD (nicotinamide adenine dinucleotide) is a molecule central to energy metabolism and cellular repair. In longevity research it is well known for its declining concentration with age. Now research published in Science points to a new function: NAD in the placenta appears to determine when contractions begin.
The researchers found that NAD levels in the placenta fall as pregnancy progresses. When those levels reach a certain threshold, signalling cascades in the placenta and uterus change in ways that initiate labour. The study describes this as a kind of metabolic clock: the placenta itself tracks how far along the pregnancy is, through NAD availability.
A metabolic timing clock in the placenta
The researchers manipulated NAD levels in mice and found they could shift the timing of birth. Higher NAD availability extended gestation; lower levels accelerated delivery. That suggests NAD is causally involved in timing, though these are preliminary findings in an animal model.
The broader implication is that the placenta does not passively wait for external hormonal signals, but actively tracks gestational progress through an internal metabolic signal.
Connections to preterm birth and longevity biology
This research is relevant in two directions. Clinically, it offers new angles on preterm birth: if NAD levels drive timing, they may be manipulable to prevent early delivery or delay it to a safer point. From a longevity perspective, it is notable that NAD, a molecule strongly associated with ageing, also plays a role in the earliest biological timekeeping. That suggests NAD-dependent processes are more broadly active than previously thought.