The provision of Neonatal Intensive Care is impacted by the lack of centralised monitoring systems within infant ICUs and the inability for Neonatologists to view data from devices attached to premature babies born in regional and remote hospitals. While web services provide a platform and language independent environment to transport numeric data streams, they must be encoded in XML, increasing the numeric data stream size considerably and thereby impacting its transmission time and the web service performance. This research assesses compression performance on XML documents containing physiological data streams to investigate the conditions where web service performance can be improved through the compression of XML numeric data streams. The compressors are applied to several XML physiological data streams output by a neonatal monitoring device. A key benefit of this research is its specific focus on numeric data streams within web services.