Article image

A mother's stress shapes her firstborn daughter's development

Did you know life’s journey might start even before your first breath? A new study from UCLA suggests a mother’s stress during pregnancy can influence how quickly her firstborn daughter matures.  

The study focuses on the invisible connection between a mother’s emotions and her child’s development, even before birth.

“This is a first-of-its-kind finding and is fascinating to look at through an evolutionary lens,” said UCLA anthropologist Molly Fox, who led the study.

Maternal emotional state 

This 15-year study in Southern California followed over 250 mothers and their children from birth to adolescence. The researchers aimed to investigate whether maternal emotional state during pregnancy influences the timing of puberty in their offspring.

The study was primarily focused on first-time mothers around 30 years old. Throughout pregnancy and the postpartum period, researchers assessed maternal stress, sadness, and anxiety levels. 

Children’s development was closely monitored until they reached adolescence, with a particular focus on physical changes indicative of hormonal shifts associated with puberty.

Impact of stress on puberty 

Initially, the researchers suspected that stress might accelerate the development of girls’ reproductive organs. However, the study found no such effect on either girls or boys.

Intriguingly, the experts did identify earlier signs of puberty in girls exposed to prenatal stress, such as the development of pubic hair. This was measured through indicators of hormone activity like “adrenal PDS scores” and “DHEA-S levels.”

This link was particularly strong for firstborn daughters and persisted until around age 12. Notably, no such association was observed in boys between their mother’s stress and their puberty timing.

An evolutionary perspective

The research suggests that when mothers are stressed during pregnancy, their first-born daughters might be more likely to mature faster. This could help the daughter become a better caregiver for younger siblings, like a built-in nanny.

Why daughters? Well, they’re more likely to take on these roles than sons, and first-borns get the “helper” job first. The researchers think that if mom’s stressed, having a more mature daughter around might be a survival advantage for the whole family. First-born daughters are more likely to help out with younger siblings, something scientists call “alloparenting.” 

This idea connects to evolution and social behavior. Basically, having a first-born daughter who grows up faster could give mom a helping hand right away, which benefits everyone. The younger kids get care, mom gets a break, and the daughter learns skills that might help her be a good mom someday too.

Broader implications 

“This research adds to the body of knowledge in our field showing the significant and lifelong impacts to women and their offspring when it comes to prenatal emotional, environmental and other factors,” said Dr. Fox. 

“This is important as we continue to come up with practical and policy solutions that contribute to greater access to healthcare and the general well being of pregnant mothers.”

The findings call for a shift towards more inclusive healthcare models that cover the following key points.

  • Recognize the importance of emotional well-being by screening for stress, anxiety, and depression during pregnancy. 
  • Provide access to counseling, stress management techniques, and support groups.
  • Advocate for policies that protect pregnant women from harmful exposures like pollution or risky work conditions. Support broader environmental health initiatives.
  • Ensure high-quality prenatal care is affordable and accessible to all pregnant women, regardless of background or location.
  • Educate expectant mothers and families about managing emotional and environmental factors. Implement public health campaigns, prenatal classes, and resources from healthcare providers.
  • Provide pregnant women with additional resources and networks through community support systems to reduce stress and improve overall well-being.

The research shows that nurturing mothers during pregnancy isn’t just about their immediate well-being, it’s about building a healthier, more resilient future for generations to come. 

The study is published in the journal Psychoneuroendocrinology.

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates.


Check us out on EarthSnap, a free app brought to you by Eric Ralls and

News coming your way
The biggest news about our planet delivered to you each day