Phil Bachmann  I found the decision unusual in that there was a large gap between signing and the parties getting married and plenty of time for the Wife to renegotiate the agreement PRIOR to the Marriage.  So firstly the arguments of the Husband in defence ought to have focussed on that elapsed time. 
Secondly, the main question is whether the wife obtained independent legal advice PRIOR to signing.    Just like we see in post separation Binding Financial Agreements both parties are REQUIRED to obtain their own independent advice for the agreement to be binding, here the Wife did in fact obtain that independent legal advice and I am curious as to what that advice was in relation to her stillborn pregnancy and her state of mind at the time.  This does not appear to be in evidence and may in the interests of justice be something that the solicitor could be called upon to be a witness.  The Wife says "she therefore signed the agreement in spite of the advice she was given". 
It would appear the evidence was that advice given would be disadvantageous to the wife (however that may be par for the course in most pre-nups) but the question here is the wifes emotional state of mind at the time of signing and certainly that Lawyer who advised her could testify to that and what if anything she mentioned of the stillbirth at the time.   
Also open to review was the medical evidence ~ "The Wife reports receiving little professional assistance beyond a visit from a social worker at the hospital, a house call from a social worker a few days later where service agencies were discussed and one visit to a doctor and one to a psychologist at a time she could not recall" 
In particular the psychologist and social worker files on the issue could have been subpoenaed to see what the professionals said about her state of mind at the time.  
The judge may have got this one absolutely right, but then again, we dont have evidence from the Wife's lawyer as to why her state of mind was not an issue they considered in their advice and we don't have the medical records either that inform us of her state of mind at the time.  
It will be interesting to see what happens next in this case.