Background: Noninvasive prenatal testing (NIPT) has been performed worldwide to detect common fetal chromosomal aneuploidies. Methods: Pregnant women (n=3743) with advanced maternal age who visited Nagoya University for NIPT were enrolled in this study. The K6 mental stress scores, that is non-specific psychological distress scores were obtained by questionnaires which were administered pre-NIPT and postpartum. High K6 scores (10) indicate anxiety or depression. The K6 stress scores at pre-NIPT and postpartum were evaluated about the relationship between mode of conception and non-specific psychological distress using binomial logistic regression. Results: In general, 7.5% of pre-NIPT women (179/2393) and 5.1% of postpartum women (121/n) were found with high K6 scores. They also did not differ significantly based on maternal age, previous live birth, previous miscarriage, and mode of conception, i.e., natural conception, artificial insemination with husband (AIH), or assisted reproductive technology (ART). Moreover, the prenatal K6 scores were not significantly higher than those at postpartum. Conclusion: Our present data suggest that mental distress in women undergoing NIPT during pregnancy and after birth has no statistical relationship with maternal age, previous live birth, previous miscarriage, or infertility treatment, and continuous mental care may help reduce mental distress in the postpartum period.