Breast-feeding practices and infant behaviour

As described in section 1.1.5, breast-feeding prevalence is strongly influenced by socio-demographic and behavioural factors. Infant behaviour can influence maternal breast-feeding practices as well as influence the demand for energy. For instance, an infant perceived to be fussy, might probe the mother to breast- feed more as a soothing technique, resulting in higher milk and energy intakes352_{. On the other hand, crying more could increase energy expenditure,}

especially if the time spent on crying is replacing the time spent asleep353. Essentially, exclusive breast-feeding is concerned with adequate milk intake to fulfil infant energy requirements, but how this milk is delivered in terms of frequency and duration of breast-feeds is determined by maternal breast- feeding practices. Furthermore, the maternal perception of her own breast- feeding practices influences her decision to persevere with or stop breast- feeding. There is a lot of research published on behavioural aspects of breast- feeding practices, and it is beyond the scope of the present thesis to explore this area fully. However, since behaviour and lactation physiology may be connected, it is relevant to include a few simple measures of infant behaviour and breast- feeding practices to test the Reilly-Wells hypothesis from a behavioural perspective (Chapter 7).

2.6.1 Baby Behaviour Diary

A diary, first developed by Barr and colleagues in 1988354, was adapted for the present study. The original diary was validated against audio-recordings, and significant moderately positive correlations were found between these and the diary records of crying time, although the study was quite small (n = 10 infants at 6 weeks of age)354_{. This diary has also been called “the Crying Diary” or “the}

Colic Diary”, and has been widely used for research in infant cry355-357 and colic behaviour358,359. For the present study, the diary was named the “Baby Behaviour Diary” (BBD) (Appendix A.12). In the BBD, infant behaviour is divided into six categories; (1) Sleeping, (2) Awake and content, (3) Awake and active, (4) Fussy, (5) Crying and (6) Feeding, as defined in Table 2.3.

Table 2.3 Definitions of behavioural categories for the Baby Behaviour Diary.

Category Description

Sleeping Quiet with eyes closed.

Awake and content Open eyes, orientation, minimal movement of arms and legs.

Awake and active Actively moving of arms and legs e.g. to engage in play or respond to stimulus.

Fussy Unsettled, irritable, restless or fractious and may be vocalising but not continuously crying

Crying Periods of prolonged distressed vocalisation

Feeding Latched on to breast or bottle of expressed breast milk, or in the process of eating complementary foods

Each category has its own shading pattern, as shown in Figure 2.7. The time ruler has an upper and lower segment, for recording infant behaviour and care- giver activities with the infant, respectively. The time ruler corresponds to 24 hours, divided into four lines of 6 hours, which are then subdivided in hours and 15-minute segments (Appendix A.12).

The mother was told to record infant behaviour by using the appropriate shading pattern as accurately as she could within the segments of 15 minutes. However, it was acknowledged that due to the need to attend to the infant as well as other activities, the mother could not keep the diary on continuous prospective basis. Therefore, she was advised to fill it in, whenever she could find time to do so. This way of keeping the diary did introduce a risk of memory bias. However, this compromise was deemed necessary to ensure sufficient compliance and obtain the data.

The diary was kept for three consecutive 24-hour periods at each time-point between the second and third visits, on the days where there was no urine sampling (days 3, 4 and 5). From the BBD, data were obtained on the frequency and duration of breast-feeds as they had been prospectively recorded by the mother over the three days. These were averaged to produce an average frequency and duration at each time-point.

2.6.2 Breast-feeding practices

To devise and validate a measure of breast-feeding practices is a very labour intensive process and this was beyond the scope of the First-Feed study. Instead, a questionnaire was adapted from a large-scale American questionnaire.

The Infant Feeding Practices Study

The American Centers for Disease Control and the Food and Drug Administration have conducted the Infant Feeding Practices Study (IFPS) I (1993-1994) and II (2005-2007). The main objectives of IFPS-II were to evaluate the effect of a national breast-feeding promotion campaign that ran from 2004 - 2006 as well as evaluating the effects of the various changes in policies, information and education relating to infant feeding choices that had taken place in the intervening period360. The IFPS-II was a longitudinal postal questionnaire survey with approximately 4,900 pregnant women enrolled during their third trimester. They were sent 12 questionnaires from time of enrolment through to 12 months post-partum. The questionnaires explored a wide range of aspects of infant feeding practices, infant health and infant care361. All the survey questions from this questionnaire study had been extensively reviewed.

The questionnaires were divided into various modules, and the modules related to breast-feeding practices were adapted for the First-Feed study. The adaptations made involved changes of spelling (for instance changing “mom” to “mum”) and omitting sections of the questionnaire concerned with brands of breast-pumps and breast-pump strategies, since these were deemed less important for the present study. Questions on initial breast-feeding (the first 2 weeks after birth) were included as part of the background questionnaire (see Figure 2.2). These were answered retrospectively on visit 1. All questionnaires used in the First-Feed study can be found in Appendix A.4, A.10 and A.14, but not all results from these are reported in the present thesis.

Breast-feeding practices questionnaire

The adapted questionnaire for current breast-feeding practices consisted of 26 items divided into four modules concerning breast-feeding at present, breast- feeding in future, breast-feeding attitudes and sleeping arrangements. The questionnaires were completed by the mother at the first visit of each time- point, at the mid-way visit, and at 9 months (sent by post) and follow-up visit, if the mother was still breast-feeding. It was emphasised that the questionnaires needed to be filled in before the three days of recording infant behaviour during the 1st and 2nd time-points, so that the responses in the questionnaires were not influenced by what the mother had just recorded in the BBD. In this way, the questionnaires were thought to reflect how the mother perceived the breast- feeding practices, while the BBD actually recorded the breast-feeding behaviour in terms of frequency and duration.