Relaxation Intervention to Improve Newborn Growth and Maternal Well-being

Weight will be measured with the Seca 334 Infant Scale (Seca Inc., Wandsbek, Germany), which is portable for study visits at home or in hospital or clinic and is accurate to 5 grams. WAZ will be calculated from measured weight using the World Health Organization (WHO) Anthro Survey Analyser. Change in WAZ will be calculated by subtracting WAZ at birth from WAZ at 12 weeks of age.

Breastfeeding behavior including frequency and duration will be assessed

Infant receipt of any feeding other than human milk since the last study visit will be assessed. We will query mothers about infant dietary intake since the last study visit including human breast milk, formula or any other feeding type such as juice or cow's milk. Infants who have received only human breast milk since the last study visit will be categorized as "no" for this outcome. Infants who have received any type of feeding other than human breast milk will be categorized as "yes" for this outcome.

Milk transfer from mother to infant will be measured in grams using the Breast Milk Intake Function of the Seca 334 Infant Scale. We will subtract the infant's pre-feeding weight (measured in grams) from the infant's post-feeding weight (measured in grams) to determine grams of milk transferred from mother to infant during the feeding.

Maternal stress will be measured at birth and at 4 and 12 weeks after birth using the Perceived Stress Scale (PSS), a tool which has been validated in the Ugandan postpartum population and which assesses participant stress over the past month. We will use the 10-item version of the PSS which has a minimum score of 0 and a maximum score of 40. Higher scores on the PSS are associated with increased stress.

Maternal anxiety will be measured at birth and at 2, 4 and 12 weeks after birth using the Generalized Anxiety Disorder 7-item scale (GAD-7), which has been validated for use in the Uganda. The GAD-7 has a minimum score of 0 and a maximum score of 21, with higher scores indicating higher levels of anxiety. The GAD-7 assesses participant anxiety over the past two weeks, so we will assess mothers using the GAD-7 at intervals no more frequent than 2 weeks.

Maternal depression will be measured at 1, 2, 4, and 12 weeks after birth using the Edinburgh Postnatal Depression Scale (EPDS). The minimum score on the EPDS is 0 and the maximum score is 30, with higher scores indicating increased risk of depression.

Secretory immunoglobulin A levels in breast milk will be assessed with enzyme-linked immunosorbent assay (ELISA)

Immunoglobulin G levels in breast milk will be assessed with enzyme-linked immunosorbent assay (ELISA)

Adverse events will be measured at 1, 2, 4 and 12 weeks after birth by querying participants regarding fever, difficulty feeding, difficulty breathing, cough, rash and diarrheal illness since the last study visit.

For participants in the intervention group, fingertip temperature will be measured with the Gentle Temp 720 Thermometer (Omron, Inc.) before and after listening to the audiorecording intervention at each study visit.

For participants in the intervention group, heart rate will be measured with the BP7100 Series 3 (Omron, Inc.) before and after listening to the audiorecording intervention at each study visit.

For participants in the intervention group, blood pressure will be measured with the BP7100 Series 3 (Omron, Inc.) before and after listening to the audiorecording at each study visit.

For participants in the intervention group, actual use of the audiorecording will be measured by self-report of how many times the audiorecording was used in the past 24 hours