We knew that pregnancy was not a health walk. But we didn’t really know how to quantify it. Until researchers at Monash University in Australia decide to look into the energy cost of “standard” human pregnancy. Result ? Nearly 50,000 calories over nine months, the equivalent of 50 Ben & Jerry’s ice cream pots engulfed in the small spoon.
The “baby” is not the bulk of the work
Scientists tended to think so far that most of this expenditure was concentrated in the fetus. Logical, since it grows and has weight. However, according to the study published in Science, only 4 % of the energy consumed during a pregnancy would actually find it stored in the baby’s tissues. The remaining 96 %? It is the mother’s body burning them, to keep the engine on the move. Or as Dustin Marshall explains, an evolutionary biologist and principal author: “The baby himself becomes a comma in the equation. »»
This discovery does not only concern humans. The researchers sift through 81 species, from the goat to the snake, including microscopic organisms. Result: the larger the animal and hot blood, the more the energy bill explodes. For example, a doe needs 112,000 calories to produce a fawn. Humans, endurance champions, however, among the mammals who pay the heaviest tribe. In question? Our particularly long pregnancies and the construction of the placenta, a real logistics site between mother and child.
50 000 calories
Well beyond the simple scientific discovery, these figures offer an almost enjoyable confirmation for all the people spent there: no, fatigue, nausea and the impression of having turned into a nuclear power plant are not in the head. They reflect a titanic biological reality, long underestimated, including by research. And if we want to push the line: this gives a concrete argument to justify maternity leave, still too often perceived as a luxury.
In hollow, the study also recalls why mothers – human and animal – invest so much energy in care after birth. When you have already engulfed 50,000 calories in the project, it is difficult to let go. As Dustin Marshall sums it up: “They have already incurred colossal costs, it is impossible to stop on the way”. In short, the next time someone minimizes the impact of pregnancy on a mother, reply with figures.
