(there is a lot here and might take some time to reply to)
Suggest the early contractions were braxton hicks contractions http://www.babycenter.com/0_braxton-hicks-contractions_156.bc (from some brief reading) aka nothing unusual.
Consider if still possible other DNA tests of the fetus to determine if there are any other genetic abnormalities that could have caused this event. if you could get a full sequence you could rule out a whole lot more, but it might be expensive to do.
I am pretty unfamiliar with prenatal development to suggest what happens around week 30, so I can be no help there.
What might be worth thinking about is how this might have unfolded 100 years ago (or more). The loss of one child; while tragic and very real to you right here and now; 100 years ago would have to have been taken into your stride. A lot more was unexplained and a lot less could have been done about it; such events would have been less comfortable and more raw. I by no means want to play down your suffering, but in understanding that this sort of thing would be the norm for back then, maybe you can help yourselves realise the value and benefits of continuing to try to have another child.
Given that you were already intending to have another child; I wouldn't be about to let this stop you.
I would also mention the benefits of having several children (they get the sibling benefits).
What is the most likely cause of death? How likely is that cause?
I believe that undetermined is the large remaining factor. given that no other data is strong, I suspect all conclusions will lead here.
Given that cause, if we choose to have another child, then how likely is it to survive its birth?
Very likely live birth; Given that all known common (or uncommon) causes of death are well known and well documented. if you consider that maybe 99.9% (estimated number) of all causes of death and complications are known, have been documented and are understood now; you happened to have something strange and unknown go wrong. If there was something strange relating to the pair between you and your wife; it would be something genetic (able to be tested for), or specifically environmental (likely not going to happen again). Given that all known common causes don't very well pattern match to this case; the odds of it happening again are very very low.
Are there any other ways I could reduce uncertainty (additional tests, etc...) that I haven't listed here?
Genetic testing that is available. regular ultrasounds. I wonder if USB ultrasound devices are available yet...
Why won't doctors give probabilities?
Doctors can't give good probabilities because medicine is a soft science still. and half the time they can't understand statistics for themselves. I wouldn't blame doctors for this; it's just the way it is for now.
hope this helps; and I hope you choose to try to have more children.
Have you considered family history? It was not mentioned above is all.
Summary: My son was stillborn and I don't know why. My wife and I would like to have another child, but would very much not like to try if the probability of this occurring again is above a certain threshold (of which we have already settled on one). All 3 doctors I have consulted were unable to give a definitive cause of death, nor were any willing to give a numerical estimate of the probability (whether for reasons of legal risk, or something else) that our next baby will be stillborn. I am likely too mind-killed to properly evaluate my situation and would very much appreciate an independent (from mine) probability estimate of what caused my son to die, and given that cause, what is the recurrence risk?
Background: V (L and my only biologically related living son) had no complications during birth, nor has he showed any signs of poor health whatsoever. L has a cousin who has had two miscarriages, and I have an aunt who had several stillbirths followed by 3 live births of healthy children. We know of no other family members that have had similar misfortunes.
J (my deceased son) was the product of a 31 week gestation. L (my wife and J's mother) is 28 years old, gravida 2, para 1. L presented to the physicians office for routine prenatal care and noted that she had not felt any fetal movement for the last five to six days. No fetal heart tones were identified. It was determined that there was an intrauterine fetal demise. L was admitted on 11/05/2015 for induction and was delivered of a nonviable, normal appearing, male fetus at approximately 1:30 on 11/06/2015.
Pro-Con Reasoning: According to a leading obstetrics textbook1, causes of stillbirth are commonly classified into 8 categories: obstetrical complications, placental abnormalities, fetal malformations, infection, umbilical cord abnormalities, hypertensive disorders, medical complications, and undetermined. Below, I'll list the percentage of stillbirths in each category (which may be used as prior probabilities) along with some reasons for or against.
Obstetrical complications (29%)
Placental abnormalities (24%)
Infection (13%)
Fetal malformations (14%)
Umbilical cord abnormalities (10%)
Hypertensive disorder (9%)
Medical complications (8%)
Undetermined (24%)
What is the most likely cause of death? How likely is that cause? Given that cause, if we choose to have another child, then how likely is it to survive its birth? Are there any other ways I could reduce uncertainty (additional tests, etc...) that I haven't listed here? Are there any other forums where these questions are more likely to get good answers? Why won't doctors give probabilities? Help with any of these questions would be greatly appreciated. Thank you.
If your advice to me is to consult another expert (in addition to the 2 obstetricians and 1 high-risk obstetrician I already have consulted), please also provide concrete tactics as to how to find such an expert and validate their expertise.
Contact Information: If you would like to contact me, but don't want to create an account here, you can do so at deprimita.patro@gmail.com.
[1] Cunningham, F. (2014). Williams obstetrics. New York: McGraw-Hill Medical.
EDIT 1: Updated to make clear that both V and J are mine and L's biological sons.
EDIT 2: Updated to add information on family history.
EDIT 3: On PipFoweraker's advice, I added contact info.
EDIT 4: I've cross-posted this on Health Stack Exchange.
EDIT 5: I've emailed the list of authors of the most recent meta-analysis concerning causes of stillbirth. Don't expect much.