Test type

#1
Hello. I am working on data regarding Vitamin D deficiency among newborn babies in relation to variables such as gestational age and birth weight. The sample consists of 88 babies (49 male and 39 female babies) with different gestational ages and birth weights. I wanted to see if there is correlation between baby Vitamin D level and these variables so I used bivariate correlation test for Vitamin D and gestational age, then for Vitamin D and birth weight and there was positive correlation in both tests, but now I want to control the effect of each of gestational age and birth weight individually to find the pure correlation of each one of them, i.e., I control gestational age to find the pure correlation between Vitamin D and birth weight, then I control birth weight to find the pure correlation between Vitamin D and gestational age, is partial correlation the suitable test or not? and what if I want to control the effect of sex of baby? what test should I use?