Infant Care Raises Foetal Loss Risk in Mandrills
Parents planning another pregnancy while caring for a young child may want to weigh support and timing with a healthcare provider.
Updated on Nov. 3, 2026 in Pregnancy
Wild mandrill females who become pregnant while still caring for a dependent infant face a higher risk of losing the foetus, according to a long-term study in Gabon. The risk rises further when the infant shows more tantrum behaviour.
Why it matters
The findings show that the demands of raising a young infant can shape reproductive outcomes in later pregnancies, a pattern that helps explain how maternal workload and timing affect family planning in a wild primate. Because females who lose a foetus tend to have shorter birth intervals but more surviving offspring over the medium term, the study points to trade-offs that shape how quickly families grow.
The study followed 117 mandrill females across 356 pregnancies over 11 years in Gabon. Females who lost a foetus went on to produce more surviving offspring over the medium term than females who lost their infant after birth.
The players
CNRS (French National Centre for Scientific Research)
France's largest public research body, which led this study of wild primate reproduction through its field research teams.
PLOS Biology
An open-access peer-reviewed journal that publishes primary biological research and will carry the findings.
The details
The research team, from the French National Centre for Scientific Research (CNRS), used the long-term Mandrillus project to monitor the wild mandrills. They compared the reproductive outcomes of females who lost a foetus with those of females who gave birth and then lost their infant. The analysis found that caring for a dependent infant raises the odds of foetal loss in a subsequent pregnancy, and that infant tantrum behaviour adds to that risk.
Timeline
The monitoring period covered 11 years of observation of the mandrill population.
The findings are scheduled for publication in PLOS Biology on 3 November 2026.
The Home Front
Long-term field programs like Mandrillus offer rare decade-scale records that shorter studies cannot provide. This kind of evidence helps place human family-planning pressures, such as spacing between children, within a broader biological pattern.
If you are planning a pregnancy while caring for a young child, this research is a reminder that spacing and support matter. Talk with your doctor or midwife about timing and prenatal care options that fit your household's needs.
The takeaway
Caring for a young infant can affect the outcome of a later pregnancy, so planning support for the household ahead of a new birth is worth discussing with a healthcare provider. Keep the upcoming PLOS Biology publication date of 3 November 2026 on your calendar if you want to read the full study.
What happens next
The full findings are scheduled for publication in PLOS Biology on 3 November 2026, when the complete data and analysis will become available.
Further reading
For more on how early-life demands shape later reproduction, explore our Pregnancy coverage.
