The sample size was determined as at least 64 people for each of the experimental and control groups, with 80% power, 0.05 margin of error and 0.5 effect level. Considering the possibility of data loss later on, 70 pregnant women (140 in total) were included in each group. The groups were randomized into 2 groups using a web-based randomization program (http://www.randomizer.org). 357 pregnant women were evaluated for suitability for the study. 68 women did not meet the inclusion criteria and 149 women were not included because they did not agree to participate in the study. The pre-test of the study was completed with 70 experimental and 70 control groups (140 in total), and the post-test was completed with a total of 130 people, 69 experimental and 61 control groups.

Pregnant women who applied to the gynecology clinic and met the inclusion criteria were informed about the study. Those who agreed were informed about the purpose of the research. Firstly, the Informed Volunteer and Introductory Information Form was applied to the women, then the Personal Care Products Use Evaluation Form, Self-Efficacy Scale and Endocrine Disruptors Attitude Scale were applied. Then, the experimental group was informed about the motivational interviewing technique. A total of 3 interviews were held. The final test was made at the fourth meeting.

In this form prepared by the researcher in line with the literature, the use of cosmetic products was asked with 41 product names in five main categories such as rinsed products, products applied to the skin and not rinsed, products applied to the hair, make-up products, intimate care products; Household chemicals are asked with 12 product names (Ashrap et al., 2018; Ingle et al., 2019; Preston et al., 2021; Fruh et al., 2022; Deierlein et al., 2022). The personal care product usage frequency of the experimental and control groups was asked in a 5-point Likert type at the pre-test and post-test, and then the difference in pre-test and post-test product usage was categorized as increasing, remaining the same or decreasing.

On a five-point Likert-type scale consisting of 23 items, each item is marked as 1-does not describe me at all, 2-describes me a little, 3-undecided, 4-describes me well, 5-describes me very well.

The scale consists of 21 items. The endocrine disruptors attitude scale has two sub-dimensions: consumer behavior and nutrition and hygiene. The scale was prepared as a five-point Likert type as "I completely agree", "I agree", "I am undecided", "I disagree", "I strongly disagree".