Studies Just Discovered the Real Reason Pregnant Women Are Hungry All the Time

Cambridge scientists have uncovered a fascinating secret: unborn babies use their dad’s DNA to “remote control” their mom’s body during pregnancy. By activating paternal genes and releasing placental hormones, they influence maternal metabolism to secure more nutrients for themselves, orchestrating a remarkable battle of pregnancy nutrition and fetal development.

The nutritional 'tug of war'.

Cambridge scientists have made a groundbreaking discovery: paternal genes in fetuses can influence their mother's body to supply more nutrients during pregnancy. This finding reveals a fascinating "nutritional tug of war," where the unborn baby uses these imprinted genes to adjust maternal metabolism and maximize its growth. Meanwhile, the mother must carefully balance her energy needs to sustain the pregnancy, support breastfeeding, and prepare for future pregnancies.

The study highlights the placenta's central role in this process. Acting as a metabolic command center, the placenta releases placental hormones that prioritize fetal development. Experiments with pregnant mice demonstrated that signalling cells in the placenta, directed by paternal genes, regulate nutrient allocation to the fetus. Professor Amanda Sferruzzi-Perri, a key researcher, described this as the first direct evidence of a paternal gene influencing maternal physiology to enhance pregnancy nutrition and optimize fetal development.

Paternal genes are ‘greedy’ and ‘selfish’ and it's for the best.

Another professor described the baby’s "remote control" system as a fascinating interplay of imprinted genes that selectively activate based on whether they are inherited from the father or the mother. These genes play a pivotal role in regulating fetal development and managing the mother’s resources during pregnancy.

“Genes controlled by the father are ‘greedy’ and ‘selfish’ and will tend to manipulate maternal resources for the benefit of the fetuses, so to grow them big and fittest,” he explained. “Although pregnancy is largely cooperative, there is a big arena for potential conflict between the mother and the baby, with imprinted genes and the placenta thought to play key roles.” This intricate biological tug-of-war highlights the vital role of the placenta in harmonizing maternal and fetal health.

Mom's and dad's genes have different purposes.

The groundbreaking research sheds light on the interplay between paternal genes, maternal metabolism, and fetal development. Paternal genes drive the fetus to grow bigger and stronger by prioritizing its nutritional needs, while maternal genes regulate growth to protect the mother’s health and energy for future pregnancies.

At the heart of this balancing act are placental hormones, which act as messengers, adjusting the mother’s metabolism to allocate nutrients effectively. Professor Sferruzzi-Perri highlighted how this mechanism ensures the fetus receives what it needs without compromising the mother’s ability to sustain herself or plan for more children. This fascinating coordination of pregnancy nutrition not only shapes the baby’s health but leaves a lasting legacy on its development and the mother’s well-being.

Other studies confirm that while prenatal learning is not widely known, it shapes sensations and associations that influence us throughout life, even if we have no memory of our earliest stages.