The curriculum of the modified childbirth education (CE) program was created along with suggestions and recommendations from experts. The participants were recruited from five different health centers in Yogyakarta. the computer random block size was applied to determine the randomization (sequence 4,6,8) and allocation concealment was assured by using sequentially numbered, opaque, sealed envelopes. The participants in the intervention group are pregnant women and their husbands. The instructors employed teaching methods such as a group discussion, watching videos, and brainstorming, as well as questions and answer periods, demonstrations, childbirth simulation, and practice. The primary investigator (PI) will teach particular sessions, including maternal-fetal attachment skills, parenting skills, comfort measures, childbirth positions, as well as knowledge about anatomy and physiology during pregnancy and birth. The materials and learning methods as the control process are expected to influence the four modes as the effectors that can reduce maternal anxiety and increase maternal-fetal attachment, childbirth self-efficacy, as well as marital satisfaction as the outcomes of adaptation level. The study setting for the intervention group was conducted at the antenatal care laboratory of 'Aisyiyah University of Yogyakarta. For safety and protocol concerns during the pandemic Corona Virus Disease-19 situation, the class was set up in a big classroom and adequate ventilation that can accommodate 12 couples and is equipped with yoga mats and pillows, as well as convenient access to a restroom. The couples and researcher team were required to wear masks and wash their hand before and after entering the class. Research assistants printed handouts and lead the group through WhatsApp application to following up practicing skills at home and also respond to the question from the participant at any time. During the intervention, the health workers from the participating health centers have been invited to observe the intervention. Classes consisted of 180-minute sessions held once a week for four weeks

The control group participants in this study have attended standard childbirth education classes during the same period as the intervention group. The control group classes were conducted at the primary health centers where they were recruited, not at the university. The facilitators of the control groups were midwives who are already providing prenatal education classes at the clinics. The classes followed the government curriculum, which consists of three classes per month and does not invite husbands to participate. However, in this study, participants in the control group have four classes over a one-month period to better match the program of the intervention group. The material for the standard curriculum includes anatomical and physiological changes during pregnancy, pregnancy care, birth, and postpartum care. The classes also address family planning after giving birth, newborn care, preventing infectious disease, and procedures for obtaining a birth certificate. The midwives also discuss and debunk unhealthy local myths, beliefs, and cultural practices surrounding pregnancy, childbirth, and the postpartum period. For the fourth class, the control group has a half-hour to fill out the questionnaires and a half hour for feedback and discussion. Then the researcher and assistants have provided the control group participants with a condensed two-hour class of prenatal yoga, comfort measures, and maternal-fetal attachment activities. We conducted online briefing sessions with midwives who are the childbirth education program facilitator at five health centers. The briefing discussed the objectives of the study, the administration of the questionnaire, and the quality control issues relating to biases, fabricated data, missing data, and ethical issues. These were established in an effort to ensure consistency in the process of data collection.