A researcher at the University of New Mexico has found that offspring during and after gestation are physically affected by stress the mother experiences.
Researchers tested their predictions using 719 studies across 21 mammal species ranging from rodents to ungulates to primates, according to research documents provided by UNM evolutionary anthropologist Dr. Andres Berghänel.
The results were used to compare the effects of prenatal stress in the mammals.
Berghänel is the lead author of a study in conjunction with the University of Göttingen and the German Primate Center that aims to learn about how prenatal stress affects babies during gestation. The study was published in November in the science journal, Proceedings of the National Academy of Sciences of the United States of America.
The study found that prenatal maternal stress, or PREMS, affects offspring growth rates. The researchers proposed that because mothers undergoing adversity or stress are not able to invest as much energy in their offspring, the fetus’ growth would be stunted.
Offspring that experience PREMS early in gestation undergo an accelerated pace of life and thus grow and mature faster to compensate for the lack of maternal investment, the study states.
Berghänel said one of the reasons the study was conducted was to clear the confusion around prenatal stress.
“The developmental origins of health and disease are a very important but also very confusing topic, and we wanted to clarify this by presenting and testing a new hypothesis,” Berghänel said.
One of the researchers’ goals was to understand why there are highly variable patterns of growth rates in disadvantaged mammal offspring.
“Our comparative analysis across mammals brings order to previously ambiguous results on the effects that maternal stress has on the developing offspring,” Berghänel said. “Different studies, often on the same species, have reported that early adversity enhances, hampers or has no effect on offspring development and performance.”
This study, in contrast to some previous studies, found that early adversity does physically affect offspring during gestation. The researchers found that PREMS late in gestation slowed offspring growth because of the mother’s reduced investment. Once the offspring reached the stage of nutritional independence, it grew at the same rate of offspring that did not experience PREMS.
Whereas PREMS early in gestation resulted in offspring compensating for the lack of energy investment by the mother.
“Stress during early gestation results in unaffected growth rates during (nutritional) dependence but accelerated growth and increased size after weaning,” Berghänel said.
The accelerated growth and increased size after weaning is an effect of PREMS early in gestation, according to the study. In short, this result explains why offspring that undergo early PREMS experience accelerated growth even after birth.
Berghänel said that the study’s results could help in understanding why girls start their menstrual cycles earlier in impoverished neighborhoods. The researchers also noted that stress in early childhood can impact infant physiology and have effects that extend into adulthood.
According to the Guttmacher Institute, pregnancies are highest among poor and low-income women. An article in Pediatrics and Child Health states that because pregnancies in poor areas are associated with single motherhood, methods such as visits by pediatricians to reduce the stress of the pregnancy are helpful.
Kathleen Bickel, co-director of Birthright of Albuquerque, a crisis pregnancy center, said helping a new or soon-to-be mother with stress, especially those from poor areas, is a priority when it comes to the well being of the child.
“We try to get (mothers) into programs to try to assist her with being a good mother,” Bickel said. “We can alleviate her stress by at least getting her started with good prenatal care.”
Berghänel’s study said that consideration of the timing of stress during gestation is crucial in understanding the effects of prenatal stress. The researchers indicated that their results will be helpful to the fields of biology, medicine and psychology in understanding the effects of PREMS.
Tom Hanlon is a news reporter at the Daily Lobo. He can be contacted at firstname.lastname@example.org or on Twitter @TomHanlonNM.