Women who went through difficult experiences during their childhood tend to have their first menstruation at an earlier age compared to women who had a more favorable childhood, according to new research. These women also tend to start having children at an earlier age. The findings, which have been published in Scientific Reports, provide evidence that childhood adversities can have long-term effects on women’s reproductive characteristics.
The researchers decided to study the topic of the impact of early-life adversities on female reproductive characteristics because there is limited evidence on how these adversities shape reproductive outcomes in women. Previous studies in animals and humans have shown mixed results, and there is a lack of empirical evidence underlying the phenomenon.
The new study was based on life history theory, a conceptual framework in evolutionary biology that examines how organisms allocate their limited resources to different life activities over their lifespan. Under challenging and stressful conditions, organisms tend to adopt a faster life history strategy. In such circumstances, individuals tend to prioritize current reproduction over future reproduction, as there may be higher uncertainty about survival.
“Experiencing traumatic events during childhood might be detrimental to later-life well-being, including the risk of mental health problems and non-communicable diseases. A life-history theory provides a framework based on an assumption that exposure to early life stress should translate into accelerated reproduction,” explained study author Magdalena Klimek, an assistant professor at the Jagiellonian University Medical College in Krakow.
“However, we were surprised by the fact that relatively less is known and not much evidence is presented on how adverse childhood experiences shape later-life reproductive outcomes. We then decided to explore if and how childhood adversities (i.e., emotional, physical abuse or neglect) shape the reproductive parameters of women across their lifespan.”
To conduct the study, the researchers recruited 131 post-reproductive women born between 1929 and 1969 from a rural area in southern Poland. This community had limited access to contraceptive methods, making it a natural fertility population.
Reproductive and demographic data were collected through a personal questionnaire and verified using parish records. The women reported information such as age at menarche, age at first and last reproduction, number of pregnancies, children’s sex and birth dates, and number of miscarriages and children’s deaths. The proportion of sons to daughters born to each woman was calculated. Information about year of birth and years of completed education, as a proxy for socioeconomic status, was also collected.
“We had an exceptional opportunity to test this phenomenon in a unique community of contemporary Polish women with low usage of birth control, and for whom we had a fully traced reproductive history, starting from the age of puberty, and ending at the age of giving birth to a last child,” Klimek explained.
Childhood adversity was assessed using the Childhood Trauma Questionnaire (CTQ), a well-validated questionnaire that measures emotional abuse, physical abuse, emotional neglect, and physical neglect. The women rated various statements about their childhood (e.g., “I did not have enough to eat”) on a 5-point Likert scale.
Klimek and her colleagues found that women who experienced childhood adversities, particularly emotional and physical neglect, had an earlier age at menarche (first menstruation). Women who were emotionally abused had an earlier age at first birth. Women who experienced physical abuse had a lower proportion of sons compared to daughters.
These findings support the hypothesis that women exposed to early-life adversities may adopt a faster reproductive strategy and potentially have lower biological condition. The study also revealed that childhood adversities were associated with an earlier onset of puberty, which may be influenced by changes in the activity of hormonal systems involved in puberty initiation. Additionally, emotional abuse was linked to a faster start of reproductive life, potentially due to the impact of early attachments and the social environment on reproductive timing.
“Our study demonstrates that experiencing childhood psychological stress might have long-term consequences not only for general and mental health but also for later-life reproduction,” Klimek told PsyPost. “If we, as a society, want to improve the overall and reproductive health of women we should even strongly focus on eliminating childhood adversities as much as possible.”
The researchers did not find significant associations between childhood adversities and other reproductive outcomes, such as interbirth intervals, number of children, and age at last birth. However, it was noted that women exposed to psychological stress during early years of life may have a higher ovarian reserve at a younger age, but experience accelerated ovarian loss over time.
“One of the aspects that surprised us was that despite the earlier age at menarche and earlier age at first birth among women experiencing childhood adversities, not only was there no effect on the number of children born, but women gave birth to a lower number of sons,” Klimek said. “As having sons are more energetically costly to mothers than having daughters, we predict that the biological condition of such women might have been impaired by the effects of childhood psychological stress.”
The study had some limitations, including the potential for memory bias when recalling reproductive and childhood adversity data from several decades ago. The sample size was relatively small, and the study did not assess sexual abuse. The researchers said that future studies should consider using multi-source assessments of childhood maltreatment and explore physiological pathways and mechanisms that may mediate the observed associations.
The study, “Early-life adversities and later-life reproductive patterns in women with fully traced reproductive history“, was authored by Magdalena Klimek, Sonja Entringer, Agnieszka Matras, Mateusz Blukacz, Ilona Nenko, Andrzej Galbarczyk, and Grazyna Jasienska.
