There is little evidence linking prenatal stress to ischemic heart disease (IHD) and stroke in the offspring, according to a recent study published in JAMA Network Open.
Takeaways
- The study, published in JAMA Network Open, suggests there is little evidence linking prenatal stress to ischemic heart disease (IHD) and stroke in the offspring.
- Ischemic heart disease and stroke are highlighted as the 2 leading causes of morbidity and mortality worldwide. Despite a decrease in age-adjusted mortality, similar incidence rates are observed over time.
- The study emphasizes that the etiologies of IHD and stroke differ in younger patients compared to older ones, and traditional risk factors do not fully account for the risk in younger individuals.
- The research investigated the hypothesis that maternal exposure to severe stress during pregnancy may be a risk factor for IHD and stroke in offspring.
- While overall there is little association found between prenatal stress and IHD and stroke risks, there is a reported increased risk of IHD associated with stress exposure in the third trimester, suggesting this specific timeframe may warrant further investigation.
IHD and stroke are the 2 leading causes of morbidity and mortality worldwide, with similar incidence rates observed over time despite a decrease in associated age-adjusted mortality. In younger patients, these conditions have different etiologies than in older patients, and risk is not fully accounted for by traditional risk factors.
Additional data is needed about the etiology of IHD and stroke in younger patients. A hypothesis has arisen that maternal exposure to stress during pregnancy may be a risk factor, but the findings remain inconclusive.
Investigators conducted a study to determine the association between severe maternal stress and offspring IHD and stroke risk. Participants included live singleton births between 1973 and 2016 from the Danish Medical Birth Register and between 1973 and 2014 from the Swedish Medical Birth Register.
Exclusion criteria included missing or incomplete maternal personal identification number and mother unable to be linked to any relative. Exposure to severe stress was defined by the death of a close family member the year before or during pregnancy. The time of loss, mother’s relationship to the deceased, and deceased’s cause of death were also reported.
Diagnoses of IHD and stroke, along with associated mortalities, were the primary outcomes of the analysis. These outcomes were determined using International Classification of Diseases, 8th Revision (ICD-8), ICD-9, and ICD-10 codes. Participants were followed up until first IHD or stroke diagnosis, death, emigration, or latest available date.
Maternal covariates included marital status, country of origin, parity, age at delivery, highest education level, body mass index (BMI) in early pregnancy, smoking, family history of cardiovascular diseases (CVDs), and diseases before delivery. Offspring covariates included year of birth, sex, birth weight, gestational age, congenital heart disease (CHD) diagnosis, preterm birth, and small for gestational age.
There were 6,758,560 reported live births, 2.5% of whom were exposed to maternal stress. Follow-up occurred for a median 24.6 years, during which 0.1% of offspring were diagnosed with IHD and 0.2% with stroke. Increased rates of birth before 1978, CHD diagnosis, lower education level, and mother aged under 19 years at birth were seen in patients with IHD or stroke.
Exposed offspring had an IHD incidence rate of 0.52 per 10,000 person-years, vs 0.45 per 10,000 person-years among unexposed offspring. IHD risk in offspring was not impacted by maternal loss of a relative the year before or during pregnancy, with an adjusted hazard ratio (AHR) of 0.98.
No association was found when categorizing by deceased relative types. Loss of older child or partner had an AHR of 0.85, and of a parent or sibling an AHR of 1.03.
Cause of death was also not associated with IHD risk, with an AHR of 0.60 from death because of unnatural cause, 1.10 because of CVD, and 0.93 because of other natural causes. An increased risk of IHD was reported from third-trimester stress exposure, with an AHR of 1.50.
For stroke, an incidence rate of 0.81 per 10,000 person-years was reported among exposed offspring, vs 0.78 per 10,000 person-years among unexposed offspring. AHRs of maternal stress were 1.04 for stroke, 1.11 for ischemic stroke, and 0.95 for hemorrhagic stroke, indicating no association.
Stroke risk was increased in patients whose mothers lost a relative because of CVD, with an AHR of 1.22 for stroke and 1.41 for ischemic stroke. Type of deceased relative was not associated with stroke risk, nor was the relative time of death.
These results indicated little association between prenatal stress and IHD and stroke risks. However, there may be an association between stress in the third trimester and IHD risk, which investigators concluded is worth investigating.
Reference
Yang F, Janszky I, Roos N, Li J, László KD. Prenatal exposure to severe stress and risks of ischemic heart disease and stroke in offspring. JAMA Netw Open. 2023;6(12):e2349463. doi:10.1001/jamanetworkopen.2023.49463
