SSC, or Kangaroo Care (KC), means placing the baby dressed only in a diaper, and maybe a hat to avoid heat-loss, on the bare chest of the parent. Usually, an upright prone position is used, but side-lying, e.g., during breastfeeding, is also common. There are special tube tops or cloth slings that are used to support maintaining the KC-position over prolonged time.

SSC is probably the most studied parent-led pain relieving method for procedural pain. SSC has been demonstrated to significantly reduce pain intensity scores as measured using validated composite biobehavioral pain indicators (17), with an effect that sustains over repeated episodes of pain exposure (18). Most studies examined heel stick or injections as the source of noxious input (4, 17, 19). Skin-to-skin contact is often combined with other methods such as breastfeeding (20, 21) for an even better effect.

There is also some evidence that continuous or longer periods of SSC may diminish chronic or prolonged pain in infants. Prolonged SSC has been associated with a reduction in chronic pain scores measured using the EDIN pain scale and alteration in neuroendocrine markers suggestive of reduced pain (22). Most notably a decrease in dopamine and cortisol levels, and increase in beta-endorphin and serotonin in salivary and urinary samples. An advantage of promoting prolonged periods of SSC is that the parent and infant are already in position to use this pain-relieving method when a painful procedure is required, reducing the need to transfer the infant immediately prior to the painful event.

Thirty-six studies examining the efficacy of breastfeeding for procedural pain relief in infants were included in a recent Cochrane review, most evaluated heel stick, intramuscular injection, and venipuncture. Breastfeeding reduced pain indicators such as duration of crying, heart rate increase and the pain scales NIPS, NFCS and DAN (23). As described above, the pain-relieving effect of breastfeeding can be enhanced when combined with skin-to-skin contact but also with maternal holding (21, 24). Giving the infant expressed breastmilk in isolation of the mother however does not appear to effectively reduce pain scores (23, 25), nor does waiting 1–2 h after the breastfeeding before performing the painful procedure (26).

The pain-relieving effect of breastfeeding persists beyond the neonatal period, at least for immunizations up to 12 months age, with a reduction of bio-behavioural pain responses (27).

More than a dozen reviews have been published on music-based interventions in neonatal care (28–30), including meta-analyses demonstrating significant positive effects on infant physiological signs, oral feeding volume, stress levels, and maternal anxiety (31, 32). In procedural pain management, previous research with recorded music as well as live lullaby singing carried out by a music therapist, have shown pain relieving and stress reducing effects (33) with a reduction in NIPS pain score (34).

A recent area of research is live or recorded parental infant-directed singing and speech as procedural support (35–43). Infant-directed speech is less effective in reducing distress than infant-directed singing. Parents should therefore sing live to tailor the singing to the infant's state and responses. Parents should sing or hum with a soothing, soft, steady, slow, and constant voice.

Recorded sound of the mother's heartbeats (44–46) or intrauterine sounds (47, 48) may have some effect in reducing physiological and behavioral signs of pain.

More research is needed to confirm the effectiveness of live parental singing and recorded maternal related sounds on infant pain. If used, parents should combine these strategies with other parent-led methods such as SSC and breastfeeding (49).

Helping the infant to a comforting position during painful procedures is something that easily can be performed by the parents. Facilitated tucking means gently holding the infant in a side lying flexed posture, supported by the hands of the parents. It has been demonstrated to reduce composite scores of stress and pain (50, 51). Holding the baby in the arms of the mother alone has not been associated with effective pain relief; however, in combination with oral glucose or breastfeeding it has been demonstrated to reduce pain intensity scores (24, 52).

Other adjuvant interventions that parents can provide, though with mixed findings on pain reduction, are comforting touch in a structured way (38, 53), e.g., with Yakson touch (54, 55), or combined with other interventions, i.e., as sensorial saturation (56, 57) or nesting (55). A systematic review showed that massage can reduce pain scores and cry duration (58). It is important to combine comforting touch with more effective parent-led interventions.

While not a parent-led intervention, parents can actively participate by offering a pacifier or finger to suck to their infant following administration of a sweet tasting solution. There is moderate certainty of evidence supporting the pain-relieving effect of a small amount of sweet solution that is given in the mouth prior to a painful procedure, as measured with composite pain scores. Sucrose is the most studied substance (59, 51), followed by glucose (60, 61) and comparisons between the effectiveness of the two substances are inconclusive (62). The effectiveness of sweet tasting solutions has been linked with the concentration, i.e., that it is sweet enough (63). Concentrations of sucrose greater than 18% sucrose may be more effective, however, very high concentrations >35% do not seem to provide greater effect (59). Ensuring that the solution is given on the tip (taste receptors) of the tongue enhances the effect. While significant variation in the dosing of sucrose exists, research supports that small amounts as low as 0.1 ml repeated as necessary throughout the procedure to achieve low pain scores are effective (63). The additive effect of non-nutritive sucking has been associated with enhanced pain-relieving effect of sweet solutions (64) but according to a Cochrane-review, the evidence is of low certainty (59). While the combination of sweet tasting solution with skin-to-skin contact did not appear to provide an additive pain reducing effect in preterm infants undergoing heel stick (65), it is uncertain whether the combination may reduce needle related pain scores in full term infants (6).

Most parent-led interventions are multisensorial in nature. Conceptionally, the Neuromatrix Theory, developed by Melzack (68), an extension to his original “gate theory” of pain developed in 1965 with Wall (69) provides an underlying framework to better understand the possible efficacy of non-pharmacologic methods of pain relief. The model outlines the importance of both ascending and descending inputs to the conscious experience of pain and includes additional inputs such as the important contributions of memory and context. Mediating factors, such as context, relationships, competing multisensorial inputs and meaning have been shown to modulate the experience of pain in adults (70–72). Similarly, infants experience the affective dynamics of pain like adults (73–75). When brain regions within the descending pain modulatory system are more functionally connected, infants have a greater ability to regulate their brain activity in response to incoming noxious stimulation (73). It is not yet determined if the descending pain modulatory system operates at birth in a less functionally connected brain, like the preterm infant's immature brain (73). The descending pain modulatory system is fully functional at birth in term born healthy infants, similar to that observed in adults (73). In the context of parent-led pain care, the combination of the parent's, skin, warmth, voice, breathing rhythm, soothing touch, taste, and scent fully match and harmonize with the infants' multisensory, biopsychosocial state of being, which may modulate the affective dynamics of the infant's pain.

Intuitive parental activities, drawn from the naturally occurring patterns of successful parent-infant communication which support the infant to be heard, seen, and nurtured, can be incorporated into the guidelines for procedural pain management to foster the parent-infant relationship. What seems to be most crucial for an infant before, during and after a painful situation as well as for future painful experiences, is the extent to which the parent is emotionally available and stable, capable of noticing and contingently interpreting cues and communications implicit in the infant's behaviour, responding adequately to the infant's distress signals and being able to soothe, regulate and share the infant's states (49).

Parental advocacy addresses parents' perspectives on advocating for themselves to participate in pain management or advocating for their infant to have their pain managed (78). Advocating for their infant's needs, being involved in shared decision making and having opportunities to provide parent-led non-pharmacological measures, empowers parents to take a more active role in the prevention, assessment and management of their infant's pain and discomfort (79). Consequently, prerequisites for parent-led pain management and equal partnership in the infant's pain care, are parental presence in the NICU and proximity to the infant as well as a trusting and updated staff, and access to information and guidance (5, 78–86).

Parents feel they have a vital role in infant pain care, and they want as much involvement as possible. Both mothers and their partners express a strong desire to be present and involved in various painful procedures to comfort their infant (78, 87). Nevertheless, even though a majority of health care professionals [in some estimates, as many as 70% (88),] find it beneficial for the infant with parents present during common painful procedures i.e., nasogastric tube placement, capillary blood sampling, or venepuncture, the parent's role as a bystander increases the more invasive the procedures are (central line insertion, extubation, lumbar puncture, and intubation) (88–90).

Parental education increases parents' knowledge about strategies, self-efficacy and confidence in managing infant pain, and satisfaction with the pain management, and should therefore be incorporated into postnatal care (87). From the parents' point of view, it's a question of timing, framing and content of the knowledge sharing and collaboration. Parents state that they prefer information about pain and pain management to be provided by the staff at a pace directed by the parent and infant, in a calm, supportive and more private environment and without having to ask for it (76, 80). Parents have difficulty absorbing new information during a procedure or in a noisy room with many distractions, and parents might feel hesitant to ask questions or get in the way (76). The initial days of hospitalization are often stressful for NICU parents, but parents express that during the first week of hospitalization it would be optimal for the staff to deliver information on parent-led pain management (78).

Information to increase parent-led strategies needs to be delivered in different formats and in the many languages of our multi-cultural society (83). Research has investigated various knowledge-translational interventions e.g., available on-line videos, educational booklets, pamphlets, dedicated websites, QR codes, educational bundles, customized individual workshop sessions for parents with hands-on guidance in parent-led methods, face-to-face interaction with health care professionals (78, 83, 84, 87, 107–109). Parents (especially low literacy parents) may need better visual aids to fully comprehend the various comfort techniques (107). Even though many parents prefer electronic resources, parents still desire human interaction for learning and favor a health care professional to review the information with them face to face (78).

Co-creation of mutual knowledge is a dynamic process that is important for the establishment of a nurse-parent partnership (110) which increases the sense of equality among parents and helps them feel valued, trusted, respected, and seen as a resource (86). Open and honest communication is the basis for cooperation in pain management (110), including health care professionals' willingness to listen to the parents to find a mutually satisfactory course of action (86). Parents want for example guidance on how to interpret an infant's pain and guidance in pain assessment. A crucial factor is the freedom for the parents to choose and being listened to about how much, and in which way, they want to participate—or not (86).

In addition to formal (e.g., healthcare providers) and informal (e.g., peer groups) written and oral resources to advise parents of the importance of their role, there has been a trend towards using online e-health resources to inform and engage parents in pain care. Parents in neonatal care have reported high use and a preference for using the internet or smartphone to access information (111, 112). However, there remains a paucity of quality online resources. An evaluation of websites or mHealth apps targeted to parents of preterm infants found issues related to their credibility and moderate overall quality, with less than 11% providing any information on infant pain (113, 114). While online resources appear to be favoured by parents, parents recognize possible issues regarding the quality of the content. Parents reported that online resources created by institutions with healthcare provider input would reduce this concern.

Additionally, only 11 studies were included in a comprehensive analysis of the impact of parent-targeted eHealth educational interventions about infant procedural pain management on parental (e.g., mental health, knowledge uptake), eHealth (e.g., acceptance, use), and pain management outcomes [e.g., parental involvement, infant pain response (115)]. Findings revealed that short and engaging educational videos may positively impact parents' knowledge, confidence, and desire to be involved in procedural pain management for their infant (109, 116). Key facilitators of e-health related resources include alignment with the Baby-Friendly Hospital Initiative, modeling by Lactation Consultants, and frequent reminders (117). However, there remains a gap in our understanding if the provision of this information to parents leads to a greater parental involvement in clinical practice and subsequent reduction on infant pain. Further work in this area is warranted.

There has been a considerable movement towards ensuring that parents are included in pain standards and guidelines. The Pediatric Pain Management Standard released in April 2023 by the Health Standards Organization of Canada in partnership with Solutions for Kids in Pain, a government funded national centre for excellence is aimed to support the delivery of equitable evidence informed pain care. The standard consisting of 34 recommendations recognizes that parents are equal members of the team and should be actively involved in decision making and care decisions (126). The standard is well aligned with the Lancet commission call to action to improve pediatric pain care (127). Despite these important inroads, few guidelines issued by a national or international authority, or a professional organization or network specifically recommend or include implementation strategies for parent-led pain management, with even fewer addressing parent-led interventions in low income and low-tech settings (4).

When written instructions are available in the NICUs about pain assessment with a structure for pain documentation, and the use of non-pharmacological methods including parent-led interventions, the staff reports higher awareness on these matters than units that do not have written local pain management guidelines for everyday work (93). One of the main obstacles leading to inadequate use of non-pharmacological methods is the lack of standards and guidelines. Guidelines are important means to improve the effectiveness and consistency of care. However, the mere existence of guidelines does not guarantee the use of them (128). Adherence depends on for example ongoing training and monitoring of their use (90). Regular rotations of staff means that frequency of teaching needs must be evaluated and prioritized to increase awareness of parent involvement in pain care, pain assessment, assessment tools and parent-led interventions.

Guidelines are usually initiated and implemented in health care through a top-down approach where information filters down through a hierarchical structure. When this approach is combined with dedicated and well-informed nurses and physicians as local pain champions in each NICU, a profound long-lasting change can happen. This will improve the conditions for the pain exposed infant and welcome the parents as partners in neonatal pain management. Local pain facilitators strive to provide health care professionals the opportunity to talk about and reflect on pain management issues and professional limitations and needs (91). Interprofessional discussions will build confidence, maintain skills, and produce living guidelines. One method to support the uptake of practice recommendations, is through quality improvement initiatives, a strategy that has been emphasized in the Canadian Pediatric Standards (126).