Values of peak expiratory flow rate (PEF), ECG and Hematological variables in 250 females at their reproductive ages, made up of 123 pregnant subjects and 127 non-pregnant control group, living and/or working in kura local government area and its environs were obtained. Pearson's correlation coefficient between PEF and ages as well as ECG, Hematological and other anthropometric measurements were calculated in both groups.Multiple regression analyses were made to obtain the best prediction formula using the measured variables in pregnant and non-pregnant groups. Furthermore, graphs were plotted to show the variation of PEF with age in the subjects and controls with specific weights. Data for plotting the graphs were generated using the prediction formula generated from this study and other prediction formula generated from previous studies among Nigerians, whose best prediction formula incorporated age and height. The graphs illustrated the limitations of applying formula derived from a different race, tribe and/or generation to an entire different people with dissimilar characteristics. This lends credence to the need to make use of recently generated formula for local use.