Table 4.

Intervention design for Maa Shishu Swasthya Sahayak Samooh (maternal and child health support group) pilot intervention, phase 2.

Domain and attributes			Options		Decision		Summary rationale
Participants
	Selection criteria: parity	Primiparous only vs both primiparous and multiparous		Prioritize primiparous women but allow some multiparous women		The intervention is likely to be more impactful for first-time parents, but optimally facilitating discussion requires a large enough group. Multiparous participants may play an important role in sharing experiences and facilitating group discussion because of their experience.
	Selection criteria: birth mode	Separate groups by birth mode (vaginal and cesarean) vs keeping them together		Maintain all participants together regardless of birth mode		Women with cesarean birth have unique early postpartum recovery needs; however, with our decision to start the intervention antenatally to increase group cohesiveness, further reshuffling of groups based on birth mode would be detrimental. An extra session for cesarean births could be added.
	Selection criteria: allowing other individuals to participate	Limit to women only vs allowing or encouraging others to attend; consider attendee gender		Discourage but not prohibit others besides women from attending		Prioritizing privacy and confidentiality is key. Various family members attended some group sessions and perspectives were mixed; some were open to others attending; however, approximately half reported discomfort with non–group members on the calls, particularly men. Moderators felt that husband attendees asked important questions that contributed to the group discussion. An extra session that includes husbands or family members could be added.
Intervention
	Timing of recruitment and intervention	Recruit and begin intervention antenatally vs postpartum or recruit women antenatally and begin intervention in the early postpartum period		Recruit antenatally (28-32 weeks); hold 2 antenatal sessions (at approximately 32 weeks and 36 weeks) with 6 months of weekly postpartum sessions starting at 39 weeks; keep groups together regardless of birth date		Recruiting participants and initiating the groups antenatally provides the opportunity for participants to build rapport and relationships before the postpartum period, which may be more hectic. Inclusion of 2 groups antenatally allows for the promotion of health-promoting antenatal and birth practices. These benefits outweigh the disadvantages of the wider range in birth date and infant age possible within each group. A small number of participants will be expected to leave the groups because of severe maternal or neonatal complications.
	Group size	12 to 20 participants per group		Target 20 participants per group		Pilot group size ranged from 7 to 12. We were initially concerned that too many people per group would overwhelm the sessions. However, attrition reduced the number of participants per session. Larger groups can accommodate any reductions in group attendance associated with antenatal recruitment and attrition.
	Frequency of group calls	Weekly, twice per week, every 2 weeks, monthly		2 antenatal sessions and weekly postpartum sessions		Participants endorsed group calls twice per week; however, we anticipated feasibility concerns and eventual attrition with this intervention burden. A predictable weekly schedule routinizes the calls. We prioritized some antenatal engagement to build group familiarity before birth and meet some antenatal health education needs.
	Group call length	Between 20 to 60 minutes		Target 20 minutes, allow up to 60 minutes		Previous educational information dissemination helps calls focus on group discussion. The women seemed to drop-off with longer calls.
	Distribution of educational information	Live sharing of educational material vs dissemination of recorded content before the group call		Distribute educational material before group calls through short audio recordings; calls will include brief educational highlights		Educational material on the call and via recordings was acceptable; however, participant drop-off was higher on longer calls. Prerecorded audios allow for educational content to be accessed via an app (smartphone users) and via an IVRa system (feature phone users). Moving this education outside of the group discussion shortens the meetings, which may reduce barriers to full attendance and transitions within the group discussion.
	Moderators	Physicians vs midlevel health professionals		Community health officers, including nurse midwives or community physicians, with some specialist support		Midlevel health professionals balance training and skills required for the moderator role and resource use, and they typically have high technological literacy. Use of these individuals as primary moderators with access to specialists for complex concerns is likely to be a scalable approach. Specialists will be featured on a few calls.
	Connecting to the group call	Have network call out vs participant calls in to network or IVR		Network calls out to participants		This approach does not require the women to initiate the call, poses the lowest cost to women (no cost), and it does not exclude feature phone users. We have identified an alternative dialing platform that minimizes the disruptions observed in pilot phase 1 (ie, dialing sounds and other audio issues).
	SMS text messaging chat group	All vs some groups with SMS text messaging chat group		All participants with WhatsApp-capable phones will be added to the SMS text messaging chat group.		Some women did not have their own phone and were unwilling to accept a phone from the research team. This could challenge participation in this component of the intervention for these women, and participation in the SMS text messaging chat group using a shared phone results in privacy concerns. Text chat groups will be facilitated by intervention moderators.
	Phone type (overall and across groups)	Include only smartphones vs only feature phones vs both		Include both, mix groups where appropriate		Although access to smartphones is increasing rapidly across India, vulnerable women who may benefit more from intervention participation are less likely to have smartphones. Maintaining both phone types in the intervention is more complicated but more scalable.
Participation and engagement
	Building relationships and participation	Earlier recruitment; use of introductions and icebreakers; facilitation of WhatsApp group for better group cohesion		Highlight privacy of the group; incorporate icebreakers into each session; recruit earlier (during antenatal care)		Increasing group engagement is a top priority of our intervention with our strong focus on social support. Improving participation and group dynamics requires a multi-pronged approach.
	Privacy	Use names vs anonymous; privacy reminders; disclose other listeners; allow for call recording or not; provide earphones		Use the women’s first names and ask how they want to be addressed; do not allow participants to record discussions without permission		There is an inherent tension between respecting privacy and confidentiality and building relationships within the group. Our moderators will prioritize the comfort level of each group’s participants. Where participants are interested in recording group discussions for sharing with others, this will only be allowed with permission from the full group.
	Participation mechanism	Raise hand via pressing a number vs being unmuted all the time; calling on participants vs natural flow		First focus on promoting spontaneous discussion via unmuting all and then move to calling on people as needed		Ensuring that group discussions participation is easy for our participants while limiting external noise that may distract or make it hard to hear. We will integrate more structured opportunities for building group cohesion to promote comfort with discussion.

^aIVR: interactive voice response.