Pregnant women included in the experimental group will be asked for written informed consent before the NST application, and the Pregnant Descriptive Information Form, State Anxiety Scale and Visual Comfort Scale will be completed. Then, the NST device will be connected to the pregnant woman and the Stress ball application will be started. During the NST procedure (average 20-30 minutes), the pregnant woman will lie on her left side. A stress ball will be placed in the active hand of the pregnant woman. The pregnant woman will be instructed to squeeze the stress ball for 2-3 seconds and then relax the hand and arm. This process will be repeated throughout the NST. During the NST application, the pregnant researcher will remain under the supervision of the midwife/nurse. The State Anxiety Scale and Visual Comfort Scale will be repeated immediately after the NST procedure. The NST result form will be filled out according to the NST printout.

Written informed consent will be obtained from the pregnant women in the control group before the NST application, and the Pregnant Descriptive Information Form, State Anxiety Scale and Visual Comfort Scale will be completed. Then the NST device will be connected to the pregnant woman. Pregnant women in this group will not be given a stress ball. During the NST procedure (average 20-30 minutes), the pregnant woman will lie on her left side. During the NST procedure, the pregnant woman will remain under the supervision of the researcher midwife/nurse. The State Anxiety Scale and Visual Comfort Scale will be repeated immediately after the NST procedure. The NST result form will be filled according to the NST trace.

During the NST procedure (average 20-30 minutes), the pregnant woman will lie on her left side. A stress ball will be placed in the active hand of the pregnant woman. The pregnant woman will be instructed to squeeze the stress ball for 2-3 seconds and then relax the hand and arm. This process will be repeated throughout the NST.

The scale was created by Spielberger. Its Turkish validity and reliability was performed by Öner and Le Compte. It is a 4-point Likert-type scale consisting of 20 questions measuring the anxiety levels of individuals. The scale includes items that are expressed positively and negatively. In the scoring phase of the scale, the total weighted score obtained for the direct statements is subtracted from the total weighted score of the reversed statements. A predetermined and unchanging value is added to this number. This unchanging value is 50 for the State Anxiety Scale. The last value obtained gives the anxiety score of the person. The scores that can be obtained from the scale vary between 20 and 80, and high scores indicate a high level of anxiety. The Cronbach alpha value of the original scale is between 0.94-0.96 and has a high internal consistency.

The Visual Analog Scale (VAS) is a reliable, valid and sensitive self-report measure for the examination of subjective patient experiences including pain, nausea, fatigue and dyspnea.The VAS scale consists of 0-10 points. Pregnant women will be asked to mark a number according to the comfort they feel. A score of '0' indicates feeling uncomfortable, while a score of '10' indicates the highest level of comfort.

This form was created by utilizing the literature. In the form, 6 criteria including basal fetal heart rate, number of fetal movements, variability (present/absent), number of accelerations, number of contractions (40 mm/Hg and above) and reactivity in NST interpretation (reactive/nonreactive) will be evaluated. Reactive NST; The test result will be considered as reactive NST if the electronic fetal heart rate tracing recorded in a 20 minute time period has at least two accelerations lasting at least 15 seconds and 15 beats/minute more than the initial beat. Nonreactive NST; The test result will be considered nonreactive NST if the electronic fetal heart rate trace recorded during the 20 minute time period does not have at least two accelerations lasting at least 15 seconds and at least 15 beats/minute greater than the baseline beat.