We appear to be in the middle of an infertility epidemic: millions of women receive the services of clinics that specialize in assisted reproductive technologies hoping for a healthy and happy outcome: baby or babies. 
Women have received the diagnosis of “unexplained infertility” and some of them look to ways to enhance the success of the procedures: mind-body meditation programmes, Acupuncture, Traditional Chinese Medicine, Naturopathic care and Hypnosis.
From before the moment of conception to the moment of birth, very powerful subconscious programs are established that are then re-accessed as she contemplates becoming a mother. If the subconscious mind believes that having a baby could jeopardize her safety and/or survival – even if this belief makes no sense to the conscious mind – then it will not allow pregnancy to occur, or if it occurs, not allow it to continue to term.
As mammals, the human mind is designed to reduce fertility when food supplies are low and when it feels unsafe. Human hormones are exquisitely balanced so that even the slightest hint of stress is relayed to the reproductive system and the body ensures that pregnancy does not occur. The stress hormones cortisol and adrenaline produced by the adrenal glands interfere with reproductive hormones such as FSH (follicle stimulating hormone) and LH (luteinizing hormone) in both men and women. This in turn decreases testosterone, estrogen and progesterone.
Chronic stress can stop ovulation, menstruation and significantly lower sperm counts.
One of the most important blocks to fertility is safety… if her sub-conscious mind does not believe that a pregnancy is safe, it will not let it happen. If pregnancy is associated subconsciously with trauma (i.e. miscarriage), her mind will ensure that she is not further re-traumatized and make sure that conception doesn’t even happen.
I’ve worked with clients for years in supporting them to release the trauma from a previous miscarriage to allow space in the body, like the state of acceptance that is encouraging to pregnancy.