BACKGROUND:Little is known about the association between the anxiety toward the effects of radiation on reproduction caused by the Fukushima nuclear accident and the birth rate of people in Fukushima. Therefore, we examined changes and associated factors of future pregnancy intention among mothers in Fukushima Prefecture. METHODS:Using data from three postal surveys among women who registered their pregnancies in the prefecture (N = 6,751 in 2012, N = 6,871 in 2013, and N = 6,725 in 2014), we analyzed the factors associated with women's intention of future pregnancy using multivariable logistic regression models. RESULTS:The proportion of mothers with pregnancy intention increased from 53.5% in 2012 to 57.9% in 2014, especially among multiparas (P for trend <0.001). Factors inversely associated with pregnancy intention of both groups were older maternal age (adjusted odds ratio [aOR] 0.92 for primipara and 0.87 for multipara), poor subjective health (aOR 0.75 and 0.81, respectively), and presence of depressive symptoms (aOR 0.71 and 0.79, respectively) (P < 0.01 for all items). In addition, not living with husband (aOR 0.24), dissatisfaction with obstetrical care (aOR 0.89) and child abnormalities (aOR 0.72) were inversely associated with pregnancy intention among primiparas, while receiving infertility treatment (aOR 2.05) was positively associated among multiparas (P < 0.01 for all items). A separate analysis of 2012 and 2013 data showed that concern about radiation contamination of breast milk was associated with pregnancy intention among primiparas (aOR 0.61, P < 0.001). CONCLUSIONS:Mothers' concern about radiation was associated with lower pregnancy intention, especially among primiparas. Providing quality obstetrical and mental health care and parenting support may be the keys to maintaining the temporal increase in fertility.