Support programs and training should be provided to parents by healthcare professionals, especially neonatal nurses and midwives, in line with these basic newborn care needs. Fathers, in particular, express a greater need for training because they feel less competent than mothers in newborn care. The concept of self-efficacy was first introduced by Bandura and defined as "individuals' beliefs in their capacity to organize and perform the actions necessary to perform assigned tasks". Self-efficacy is, in another definition, the belief that individuals have in themselves in the face of any situation they encounter, and these self-efficacy beliefs vary from situation to situation. If individuals have low self-efficacy, they will not find themselves competent in the situation they encounter and may not be able to do the task even if they have the capacity to do it. In this context, low self-efficacy levels of fathers in newborn care negatively affect their participation in care. During the prenatal period, expectant fathers' participation in childbirth preparation training and spending time with their partners allows them to focus on the baby and their partner's pregnancy. While the literature explores the emotions and experiences of pregnant women, studies on expectant fathers' cooperation during pregnancy, their self-efficacy for baby care, and their perception of spousal support are scarce. Therefore, this study aims to investigate the impact of basic newborn care training provided to expectant fathers with pregnant wives via a website on expectant fathers' self-efficacy and their wives' perception of spousal support during pregnancy.

The neonatal period encompasses the first 28 days after birth. Babies born between 38 and 42 weeks are classified as term newborns, those born before 37 weeks as premature babies, and those born after 42 weeks as postmature babies. The newborn must experience physiological changes and adaptation in their body systems with birth. While completely dependent on the placenta for gas exchange, thermoregulation, nutrition, and excretion of metabolic products during the intrauterine period, they perform these functions independently after birth. However, because the newborn's systems are not fully developed like those of adults, they have difficulty performing these functions in the first days, and deviations from normal can occur within a short time. Therefore, ensuring and maintaining hemostasis in newborns is one of the primary goals of neonatal care. A baby's health and quality of care during the intrauterine, birth, and neonatal period affect their entire life. Therefore, a healthy newborn period, from birth to the intrauterine period, and optimally meeting their care needs will lay the foundation for the rest of their life. The most important of these care needs relate to the newborn's hygiene, safety, and nutrition. Support programs and training should be provided to parents by healthcare professionals, especially neonatal nurses and midwives, in line with these basic newborn care needs. Fathers, in particular, express a greater need for training because they feel less competent than mothers in newborn care. The concept of self-efficacy was first introduced by Bandura and defined as "individuals' beliefs in their capacity to organize and perform the actions necessary to perform assigned tasks". Self-efficacy is, in another definition, the belief that individuals have in themselves in the face of any situation they encounter, and these self-efficacy beliefs vary from situation to situation. If individuals have low self-efficacy, they will not find themselves competent in the situation they encounter and may not be able to do the task even if they have the capacity to do it. In this context, low self-efficacy levels of fathers in newborn care negatively affect their participation in care. Another study found that the self-efficacy levels of mothers and fathers in the intervention group improved after newborn care and parenting preparation training provided to parents in the early period through a mobile health application. Therefore, it is extremely important that fathers who care for newborns receive various trainings to increase their knowledge and skills about newborn care before and immediately after birth. During the prenatal period, expectant fathers' participation in childbirth preparation training and spending time with their partners allows them to focus on the baby and their partner's pregnancy. Furthermore, it has been reported that supporting their partners during pregnancy has a positive effect on the baby's cortisol levels in the intrauterine period and has a protective effect on the baby's health. It is emphasized that pregnant women often need spousal support during pregnancy and birth, that spousal support makes pregnancy less stressful, and that failure to provide adequate spousal support when needed can lead to irreversible problems. It has been reported that low perception of spousal support during pregnancy is associated with neonatal outcomes such as newborn weight, neonatal distress, and prematurity, and that it negatively affects mother-infant bonding and breastfeeding. While the literature explores the emotions and experiences of pregnant women, studies on expectant fathers' cooperation during pregnancy, their self-efficacy for baby care, and their perception of spousal support are scarce. Therefore, this study aims to investigate the impact of basic newborn care training provided to expectant fathers with pregnant wives via a website on expectant fathers' self-efficacy and their wives' perception of spousal support during pregnancy.

H11: Basic newborn care education provided to expectant fathers through the website has a positive effect on fathers' self-efficacy.

H21: Basic newborn care education provided to expectant fathers through the website has a positive effect on expectant mothers' perception of spousal support during pregnancy.

Inclusion Criteria:

The study required the following criteria for participating fathers:

• Their wife's pregnancy was in the third trimester
• They were over 18 and under 50
• They agreed to participate in the study and signed the voluntary consent form
• They had internet access on their phone
• They knew how to use a telephone
• They could read and understand Turkish
• They were oriented to place, time, and person
• They had no problems with their wife's pregnancy
• They had no communication or visual impairments.

The study included mothers who were:

Pregnant women were included if they:

• were over 18 but under 50 years old
• were in their third trimester of pregnancy
• agreed to participate in the study and signed the voluntary consent form
• knew how to use a telephone and had internet access on their phone
• could read and understand Turkish
• were oriented to place, time, and person
• had no communication or visual impairments.

Exclusion Criteria:

• participated in the study but did not wish to continue in the future
• had a child or spouse develop a health problem during the study period
• did not visit the website during their wife's pregnancy or did not follow the practices.

The researcher will not be informed of the group placement of expectant fathers and mothers according to the randomization table before data collection, and the researcher will be blinded during group assignment. The researcher, who will also provide the training, will be blinded during the assignment of fathers to groups, but will not be blinded during the training and evaluation phases. Once the data collection process is complete, the data will be transferred to a computer and analyzed by an expert independent of the research. This will ensure that the researcher and the independent expert are blinded during data analysis and group assignment.