Assisted Conception Linked to Kawasaki Disease Risk in Children, Finds JAMA Study
Japan: Researchers have found in a Japanese cohort study published in JAMA Network Open that ovulation induction, intrauterine insemination, and in vitro fertilization (IVF) were associated with Kawasaki disease among children younger than 5 years. The specific cause of Kawasaki disease remains elusive, and further research is needed to understand the potential link between assisted conception and disease development.
Kawasaki disease (KD) is an acute inflammatory condition affecting children and is recognized as one of the leading causes of acquired heart disease in children in high-income countries. With the use of fertility treatments increasing worldwide, researchers led by Sachiko Baba of the Osaka Maternal and Child Information Center, Osaka Women’s and Children’s Hospital, Japan, examined whether assisted conception was associated with the development of KD during early childhood.
The researchers conducted a nationwide prospective cohort study using data from the Japan Environmental and Children’s Study. Pregnant women were recruited between January 2011 and March 2014, and their children were followed until 59 months of age. The analysis included 101,864 children and compared spontaneous conception with assisted conception, including ovulation induction, intrauterine insemination, IVF, and intracytoplasmic sperm injection (ICSI).
During 431,558 person-years of follow-up, 1,226 children developed Kawasaki disease. The overall incidence was 284 cases per 100,000 person-years, compared with 274 among children conceived spontaneously and 391 among those conceived through assisted methods.
The findings showed:
- Assisted conception was associated with a 42% higher risk of Kawasaki disease compared with spontaneous conception (adjusted hazard ratio [AHR], 1.42).
- Ovulation induction was associated with increased KD risk (AHR, 1.57).
- Intrauterine insemination was linked to a higher risk (AHR, 1.48).
- IVF was associated with an increased risk of KD (AHR, 1.53).
- No significant association was observed with ICSI (AHR, 0.91).
The associations remained after additional adjustment for maternal endometriosis, polycystic ovary syndrome, allergic conditions, and autoimmune disease.
The study has several limitations. Statistical power may have been limited for smaller treatment groups, particularly children conceived through ICSI. Misclassification of fertility treatment methods was also possible, although medical records were used. Detailed information on treatment protocols, ovarian stimulation regimens, culture media, and embryo characteristics was unavailable. Some KD cases may have been missed if parents did not report them, while unmeasured factors such as genetic influences were not accounted for.
The researchers concluded that most fertility treatments, except ICSI, were associated with an increased risk of Kawasaki disease among offspring. Further studies are needed to determine whether these findings are reproducible and to clarify the biological mechanisms that may underlie the observed associations.
Reference:
Baba S, Tanigawa K, Miyazaki J, et al. Fertility Treatments and the Risk of Kawasaki Disease Among Offspring. JAMA Netw Open. 2026;9(8):e2628586. doi:10.1001/jamanetworkopen.2026.28586
Next Story