Changes to infant sleep practices in Canterbury

"Reducing the risk" is a public health primary initiative to minimise the incidence of Sudden Infant Death Syndrome (SIDS) in New Zealand. A number of SIDS risks relate to infant sleep practices. We describe current prevalences of these practices.

A cohort of Canterbury mothers delivering live infants during May 1997 (n = 411) were mailed a questionnaire in July surveying their infant's sleep practices. Survey results were compared to results derived from the Canterbury control infant component of the 1987-90 New Zealand Cot Death Study (NZCDS) (n = 174). Those mothers using either plastic or rubber mattress covers (n = 63) were issued a subsequent questionnaire pertaining to this mattress-wrapping practice.

Completed questionnaires were returned by 274 (66.7%) mothers. Room sharing with mother was usual for 133 (48.5%) infants, no different from the 94 (54.0%) recorded in the NZCDS (chi 2 = 5.6, df = 2, p = 0.06). However, of those infants sharing a room with their mother, 101 (75.9%) slept in their own bed compared to 46 (48.9%) in the NZCDS (chi 2 = 57.0, df = 2, p < 0.01). Only 8 (2.9%) infants were regularly placed prone to sleep, considerably fewer than the 69 (39.7%) reported in the NZCDS (chi 2 = 100.1, df = 1, p < 0.01). Mattress-wrapping with plastic (14.6% vs. 4.0%; chi 2 = 12.8, df = 1, p < 0.01) and rubber (8.4% vs. 3.4%; chi 2 = 4.4, df = 1, p = 0.04) has significantly increased since the NZCDS. Results from the subsequent questionnaire, completed by 42 (66.7%) respondents, indicated that most, 25 (59.5%), wrapped their infant's mattress to stop soiling. Less than half, 18 (42.9%), wrapped the mattress for the "safety of their baby".

The "non-prone sleeping" campaign has been successful in Canterbury. Most infants are now routinely placed non-prone for sleep. Of those infants sharing a room with their mothers, an increased proportion is sleeping in separate beds. The use of "drycot" under-blankets and sheepskins has diminished. While impermeable mattress-wrapping usage has significantly increased, over three-quarters of Canterbury mothers did not use plastic or rubber mattress-covers on their infant's beds.