Natural selection is random and an accident. A woman has a miscarriage for a number of reasons. A bad mutation is just one reason.
Seven Most Common Miscarriage Causes
But my point stands. Mutations are accidental changes. Natural selection implies a design if it is purposeful. If it does not then it's pure chance.
Stand back while I eviscerate your claim. Looking through that list, they are all reasons attributable to natural selection with the possible exception of lifestyle - and that's debatable. Mutations are accidental changes, though this is as accidental as gravity. Natural selection doesn't imply design, but let's look at your list and see how we go...:
1. Chromosomal Abnormalities - If an organism's DNA isn't up to par to carry out its complex biochemical reactions, it's a non-starter. No intelligence required.
2. Uterine Abnormalities and Incompetent Cervixes - if the parent organism carries mutations that prevent reproduction (such as these deformities) then again, no matter how competent the embryo, it has a reduced chance for being born, and the parent's abnormalities aren't passed on. No intelligence required.
3. Immunologic Disorders - These are traits usually of the Parent organism's immunologic responses incorrectly attacking the pregnancy which again reduces the chances of a successful pregnancy, no matter how viable the embryo is. No intelligence required.
4. Polycystic Ovary Syndrome - As stated, ever more common in infertility due to the imbalance of male/female hormone of the female parent. If left to run its natural course, a pregnancy is much less likely to be successful, removing these adverse parental traits from being passed on. No intelligence required.
5. Bacterial Infections - as indicated, If the parent organism's immunological defences are strong, then there's an increased chance that these advantages in immunities result in a pregnancy carried to term and advantages passed onto the child, otherwise, a failure of the organism to overcome biologically superior organisms (in this case, bacteria) resulting in failed pregnancies. No intelligence required.
6. Lifestyle - As I mentioned, this point is debatable. An organism that has bad self-control or is born with traits making it more susceptible to addictions that lead to degraded health could easily be a victim of natural selection by means of its own self-harm. Apart from its own choices and course of action putting it at a disadvantage for reproduction, No intelligence required.
So, in every example above, natural selection acts upon the organisms (whether they be parent or child) preventing the disadvantageous traits from being passed on just as gravity attracts bodies of matter. It isn't like a filter makes smart decisions about what to let through and what not to, it's just preventing the natural flow of contrary matter through the inherent laws of physics in our universe, and nothing more. None of it is pure chance and by the same measure, no intelligence was required either...