The goal of this clinical trial is to evaluate the effect of transtheoretical model-based antenatal and postnatal motivational interviewing on contraceptive self-efficacy, contraceptive attitude, and postpartum contraception use. This study was planned as a single-centre, parallel-group, randomized controlled trial design. The study group consisted of 72 women at 28-32 weeks of gestation (intervention group n=36, control group n=36). Block randomization stratified by parity will be used to assign participants to groups. The intervention group will receive antenatal and postnatal motivational interviewing in addition to routine care, while the control group will receive routine care only. Outcomes will be evaluated at 12 weeks postpartum. Data will be collected using a personal information form, Contraceptive Self-Efficacy Scale, Contraceptive Attitude Questionnaire, Contraceptive Use Form and Stages of Behavior Change Short Form.

Short gestational intervals are known to be directly associated with adverse pregnancy outcomes, such as gestational diabetes, maternal obesity, anemia, maternal mortality, severe maternal morbidity, preterm delivery, low birth weight, and infant mortality. The most important step in establishing optimum pregnancy intervals can be achieved by meeting the contraceptive needs of postpartum women. Motivational interviewing incorporates components of contraception counseling best practices, such as building trust, optimizing the decision-making process, improving self-efficacy, and protecting the autonomy of the individual, which allows it to be actively used in the counseling process. Therefore, this study aimed to investigate the effects of transtheoretical model-based motivational interviewing on postpartum contraception. In this study, the intervention group will receive two motivational counseling sessions in the antenatal period and one motivational interviewing session in the postnatal period in addition to routine care, while the control group will receive only routine care. The data will be coded as A and B in SPSS (Statistical Package for the Social Sciences) and analyzed by an independent statistical expert.

Inclusion Criteria:

• 28 to 32 weeks of gestation
• At least literate in Turkish
• Agree to participate in the study
• Willing to participate in the postpartum follow-up
• Having access to a smartphone

Exclusion Criteria:

• Women who do not have a sexual partner
• Women who give consent for female sterilization immediately after delivery

The sample of this study consists of pregnant women.

There are no plans to make individual participant data available to other researchers.

Blinding of the outcome assessors in this study was planned. The data obtained from the research will be coded as A and B by an independent researcher and transferred to the SPSS program. The data will be analyzed by an independent statistical expert.