Possibly, but could not guarantee that you would. The IGI is not a complete list, SP is more reliable, but all I can suggest is that it depends... on the dates, on the church they went to (might it have been between 1843 - 1855?) and a number of other factors, like what has survived & what has not....While on this topic (well vaguely!), were I to look at the original OPR for Cleish might I find my gt grandmother's birth and her siblings' whose births do not appear on the IGI or SP? Or are those too lost in the mists of time?
http://www.gro-scotland.gov.uk/famrec/h ... r-cov.html
460. CLEISH
460/1 B 1700-1819 M 1702-1819 D 1745-1811
460/2 B 1820-54 M 1820-54 D 1828-54
...but that does not mean that the records are complete for those periods, there may be gaps...sometimes big ones! (which may explain your missing persons)
However, I'd always be in favour of a good rummage in the OPRs - its amazing what you can find - I have found things which were listed wrongly in the IGI and SP, and things which appear in neither online databases (deaths for instance..) Even if you don't find what you are looking for you will still have a much better idea of the area your folk lived in & the times in which they lived.
utrecht003 - please accept my apologies, this has drifted somewhat from your original enquiry
Best wishes
Lesley