Rats exposed to synthetic cannabinoids in the womb showed impaired respiratory motor control and weakened cardiovascular reflexes in early adulthood, with sex-specific patterns of vulnerability.
Pregnant women considering cannabis use, obstetricians, pediatric researchers
Both sexes showed impaired breathing reflexes; males also had weakened heart responses
What the researchers found
Prenatal cannabinoid exposure (WIN 55,212-2) caused lasting impairments in cardiorespiratory control in juvenile rats. Females showed reduced postinspiratory drive to laryngeal muscles at rest, suggesting impaired upper airway control. Both males and females showed reduced respiratory responses to low oxygen and high CO2. Males additionally showed attenuated sympathetic cardiovascular responses to these challenges.
Why it matters
Cannabis use among pregnant women is increasing, partly due to beliefs that its natural origin guarantees safety. This study shows that prenatal cannabinoid exposure can disrupt the development of brain circuits controlling breathing and blood pressure, with effects that persist into early adulthood.
The numbers in context
WIN 55,212-2 dose: 0.5 mg/kg/day during gestation. Measurements at 27-28 days old (juvenile). Females: reduced postinspiratory activity to laryngeal muscles at rest. Both sexes: reduced postinspiratory and expiratory motor responses to chemoreceptor activation and hypercapnia. Males: attenuated sympathoexcitatory responses.
How the study worked
In situ nerve recording preparations from juvenile rats (27-28 days old) whose mothers received synthetic cannabinoid WIN 55,212-2 (0.5 mg/kg/day) or vehicle during gestation. Respiratory and sympathetic nerve activities were measured during resting conditions and during chemoreceptor stimulation.
What this study cannot tell us
Animal study using a synthetic cannabinoid (WIN 55,212-2), which has different pharmacology than plant-derived THC. In situ preparation rather than awake, behaving animals. Cannot directly translate doses or outcomes to human pregnancy. Single time point assessment (juvenile).
How to read the evidence
Preliminary evidence from an animal model using synthetic cannabinoid, requiring confirmation with plant-derived THC and human studies.
When this study was published
2025 animal study examining lasting cardiorespiratory effects of prenatal cannabinoid exposure.
The bigger picture
The endocannabinoid system plays a critical role in fetal brain development, including the maturation of circuits that control breathing and cardiovascular function. Disrupting this system with exogenous cannabinoids during pregnancy may create lasting vulnerabilities in how offspring respond to physiological stress, such as low oxygen situations.
Questions still open
- Do these cardiorespiratory deficits persist into full adulthood? Would plant-derived THC produce the same effects? Could these respiratory control impairments increase SIDS risk in exposed offspring? Are the sex differences in vulnerability clinically relevant?
Common questions
Can cannabis use during pregnancy affect the baby's breathing?
Were males and females affected differently?
Read the original research
Prenatal cannabinoid exposure affects central cardiorespiratory control in young male and female rats.
Journal of applied physiology (Bethesda, Md. : 1985), 138(5), 1201-1216
Citation
Patrone, Luis Gustavo A; Karlen-Amarante, Marlusa; Gargaglioni, Luciane H; Zoccal, Daniel B. (2025). Prenatal cannabinoid exposure affects central cardiorespiratory control in young male and female rats.. Journal of applied physiology (Bethesda, Md. : 1985), 138(5), 1201-1216. https://doi.org/10.1152/japplphysiol.00044.2025
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