The variables are:
Smoke |
indicator of whether the mother is a smoker |
Lwt |
last menstrual weight of the mother |
Hosmer & Lemeshow (1989). Applied Logistic Regresion. Wiley, NY. The original source contains additional variables; see Appendix 1 of Hosmer & Lemeshow for a full list of the data, pp.29-30 and p.92 for additional information.