GRO birth indexes for 1984-2004

Receiving today's newsletter I looked at the latest indexes. I started with my own family (as you do!) and found interesting discrepancies. Although you have to specify male/female SOME of the time it returns results for all genders. The results are inconsistent in my experiments.
There is no maiden surname in the results unless you specify one. Then it is returned top of the list but all the other results are still listed without a maiden surname. I just thought this might be of interest to others.

 

I mostly use the GRO indexes to verify I have the right person by looking to see the mother's maiden name but only for those records that don't provide the maiden name.

Being intrigued by this way this discussion developed I just had to put my 'testing hat' on. I started with a male Smith for 1990 and received pages and pages of results without a maiden name in sight.
I then entered Steven for the first name and Jones for the maiden name, the results were as described by lindy.
I went to one of my trees to find somebody born in 1998 and in 2002.
For each of those people I have the Ancestry birth record from the England & Wales, Civil Registration Birth Index, 1916-2007 collection. The mother's maiden name is given in each record but there is no imager attached.
That begs the question, where can we see the new indexes?

 

Testing further, using an uncommon surname, I've had the same number of results returned for a year, with both male and female names, up to 1992. This is when I select either male or female. Then 1993 onwards it returns either male or female names as specified. I haven't checked absolutely every year but sampled and from 1993 it is correct.

 

Just did some searching myself and found that if you put in a surname & first forename & mother's maiden surname you get matches also for index entries that don't match the mother's maiden surname, ie search for Dylan Sturge, Male, Leyland (mother) in 1997: you get only Dylan Nicholas Sturge (whose mother's maiden name was Issott) so maiden surname is blank in results list.
More importantly this search doesn't return Dylan Oliver S Sturge (whose mother's maiden name was Leyland). This person can be found at FindMyPast - where both people are returned. This person is not returned at GRO even if you leave off mother's maiden name in the search criteria.
This wasn't an isolated example. One search at GRO that returned 10 males resulted in 5 more males when a similar search was performed at FindMyPast.