Study site and Population
A randomized study was conducted from November 2008 to November 2009 in a teaching hospital in the North West of England, where more than 8000 babies are born annually. Babies were included if they were born at 37 weeks gestation or more and were in good general health (determined by the investigator). Excluded babies were those admitted to the neonatal unit; having phototherapy; limb defects; non-traumatic impairment of epidermal integrity or evidence of skin disorder at first visit. For the purposes of this study, the following normal variations were not considered skin disorders; erythema neonatorum, erythema toxicum and milia. Babies were also excluded if participating in another clinical trial.
We set out to recruit a sample of babies with a family history of atopic eczema (n = 30) and a sample of babies who did not (n = 50). We believed that any effects were likely to be more pronounced in infants with a family history of atopic eczema and therefore we accounted for this in the design of the trial. These numbers were deemed to be sufficient to explore the nature and sizes of differences in outcomes and to estimate the standard deviations for each population.
The trial was approved by the Cheshire Research Ethics Committee (09/H1017/3).
Recruitment and randomization
All potentially eligible women were supplied with study information in the antenatal period and given time to consider participating. Willing participants were invited to complete a self administered questionnaire; this enabled us to screen for those with and without a family history of atopic eczema. The definition of "family history of atopic eczema" was "at least one of father, mother, or sibling, who has had a medical-diagnosis of atopic eczema and who has had topical steroid treatment". We considered this to be the simplest way of identifying babies with a predisposition for atopic eczema.
In the postnatal period a research midwife approached women who had completed the questionnaire and requested consent for their baby to participate in the trial. Consenting women were randomized to the experimental or control arm within 24 hours of giving birth and prior to their baby being given his/her first bath. Randomization was stratified according to whether or not the baby fulfilled the definition of a family history of atopic eczema. Blocked randomization was by sequentially numbered sealed opaque envelopes held in the Trust R&D Department. The randomization sequence was computer generated.
Intervention
Babies were randomized to be bathed in water only or bathed with the baby wash product. The wash product was the commercially available Johnson's® baby top- to-toe ™ wash (Johnson & Johnson Consumer Companies, Inc.). This wash is a soap-free liquid cleanser specifically designed for newborns' skin. It is sodium lauryl sulphate free and consists of a proprietary blend of non-ionic and amphoteric surfactants that, when combined, result in large, gentle cleansing micelles. The formula contains only strictly necessary levels of well-tolerated preservatives and a very low level of fragrance; it is pH adjusted (around 5.5) and hypoallergenic. The INCI list comprised Aqua, Coco-Glucoside, Cocamidopropyl Betaine, Citric Acid, Acrylates/C10-30 Alkyl Acrylate Crosspolymer, Sodium Chloride, Glyceril Oleate, p-Anisic Acid, Sodium Hydroxide, Phenoxyethanol, Sodium Benzoate, Parfum.
All participating mothers were given a demonstration bath by a Health Care assistant who had been instructed on the appropriate advice. For those allocated to the water only (control) arm, parents were not provided with any products and were advised to bathe their baby with water and cotton wool only. For those allocated to the wash product (experimental) arm, parents were provided with sufficient baby wash and advised to use the product as per instructions.
All participating parents were supplied with written guidance on baby bathing. These instructions included guidance on regularity of bathing and the non use of other products, e.g. oils, sponges, flannels and baby wipes. Participating women were requested to bathe their baby a minimum of 3 times per week. The number of times babies were bathed was recorded by the women. They were also instructed to avoid any rubbing of the baby's skin and requested not to use any additional products.
Assessment of trial outcomes
All measurements were taken by researchers who were unaware of treatment allocation. Measures were repeated to check for intra-rater reliability. At the outset we had intended to conduct all assessments in a controlled environment within the hospital setting. All baseline assessments were conducted in the hospital. The remaining follow-up assessments were also to be carried out in the hospital. However 2 months into the study it became clear that loss to follow-up was greater than expected. Of the 31 women who agreed to participate during this period, 18 (58%) failed to attend their scheduled follow-up appointments at 4 and 8 weeks. This was despite being offered transport to attend and reimbursement for their time and inconvenience. Women verbalized that attending the hospital was more disruptive than they had anticipated. As a consequence, and following discussion with the Data Monitoring Committee and the manufacturers of the assessment instruments, we decided to conduct future assessments in the home.
Transepidermal Water Loss (TEWL)
A closed chamber TEWL instrument was used to measure the flux of water vapour evaporating from the skin surface (AquaFlux Model AF200). The measurements were done by the same midwife at each time point for the same participant. The midwife was formally trained in obtaining such measurements, which were in accord with published guidelines for TEWL measurements [23]. Measurements were made twice at each of three sites. A baseline assessment was made prior to maternal transfer into the community and before first bath. A second assessment was made at 4 weeks and 8 weeks post birth. Measurements were taken on the upper abdomen (above nappy area), upper leg and forearm. The exact locations where measurements were performed were similar on all babies. This was achieved by measuring from anatomical markers such as skin crease of the wrist to midpoint on the volar forearm.
Skin surface pHand hydrationwere measured at the same times and at the same sites as the TEWL measurements using a pH meter (Courage and Khazaka skin pH meter 900) and corneometer (Courage and Khazaka Corneometer CM 820).
Clinical observations
The skin was observed and recorded by the assessing midwife, at 4 and 8 weeks post birth using a validated rating scale which records erythema, dryness, scaling and need for medical products/attention [24]. Any skin treatments were recorded by the mother.
Analysis
Data were input onto SPSS (Version 17) and double entered to ensure accuracy. In accordance with recommendations for pilot studies [25] data were summarized for the whole study group and tabulated according to allocation.
Individual experiences of women and members of the research team were recorded throughout the study to refine the study procedures for the main trial.