The Development of the Mother-Infant Mutualistic Screening Scale.

Background: The integrity of a mother-infant dyad is essential for the proper development of maternal behavior and infant growth/ development. At present, there is a lack of objective approaches to monitor mother-infant behavioral exchanges.

Objectives: This is an exploratory prospective study designed to evaluate the Mother-Infant Mutualistic Screening Scale (MIMSS), a novel observational tool focused on monitoring the mutual/ reciprocal sensitivity and responsiveness that mother and infant express toward one another's behaviors/ actions during the obligatory setting of daily meal times.

Methods: Mother-infant interactions were assessed from videotaped feeding sessions conducted under recurrent naturalistic observations. Data were collected from 27 mother-preterm infant singleton dyads at 6 and 12 month corrected age (CA). Four levels of MIMSS are defined: Level I - both mother and infant are not responsive (NR) to one another's actions; Level II - mother is not responsive (NR) to infant, but infant is responsive (R) to mother; Level III - mother is responsive (R) to infant, but infant is not responsive (NR) to mother; Level IV - both mother and infant are responsive (R) to one another.

Results: Inter- and intra-rater reliability between two raters was 93% and ≥ 85%, respectively. At 6 and 12 month CA, 78% and 81% of the dyads were at a MIMSS Level IV, respectively. A change in mother-infant reciprocal behavioral responses or MIMSS levels was observed in 9 of the dyads between these two ages. No association was observed between MIMSS levels and infant growth/ development as monitored by percentile Weight, Length, and Weight by Length at both corrected ages.

Conclusions: The MIMSS is easy to use with high inter- and intra-rater reliabilities. With the ability to differentiate between mother and infant reciprocal behavioral responses toward one another's actions, MIMSS can help health professionals assess the quality of mother-infant interactions and identify the partner(s) who may benefit from individualized assistance. Although MIMSS uses mealtime as a recurrent setting, it offers a conceptual frame work for evaluating co-regulatory processes under different contexts.