Wireless Body Area Networks (WBANs) have the potential for extensive use in health care monitoring. To provide optimum network utilization, it is important to efficiently schedule multiple co-existing WBANs which could possibly suffer from high degree of interference. A graceful coexistence can be feasible by appropriately scheduling transmissions from different WBANs. In this paper, we use a recent standard of IEEE 802.15.6 (TG6), which has been finalized in May 2012, to address the problems of intra and inter-WBAN interference. This standard offers several advantages for medical applications as compared to IEEE 802.15.4 which has been previously adopted for numerous healthcare applications. In this paper, we propose a QoS based MAC scheduling approach to avoid inter-WBAN interference and introduce a fuzzy inference engine for intra-WBAN scheduling so as to avoid interference within WBANs.