Final answer:
In the case of a 15 year old female at Tanner stage I with no menses initiation, the likely elevated hormone levels would be follicle-stimulating hormone (FSH) or luteinizing hormone (LH). Prolactin is associated with milk production post-childbirth and affects breastfeeding rather than the ability to become pregnant.
Step-by-step explanation:
The subject of this question is a 15 year old female who has not initiated menses and is still in Tanner stage I, which indicates a likely delay in the onset of puberty. In such cases, levels of certain hormones that are involved in sexual development and menstrual cycle regulation might be assessed. The hormones typically evaluated include follicle-stimulating hormone (FSH), luteinizing hormone (LH), estrogens, and gonadotropin-releasing hormone (GnRH).
FSH and LH are produced by the anterior pituitary gland and stimulate the ovaries to produce estrogen, which in turn promotes the growth and changes associated with puberty. If this individual's estrogen levels were elevated, it would indicate some ovarian activity, even if she had not yet menstruated, which might not be consistent with Tanner Stage I. Therefore, it could be hypothesized that either FSH or LH might be elevated, as they might be trying to stimulate an ovary that is not responding.
Regarding the secondary question, prolactin is involved in stimulating milk production in the mammary glands following childbirth; hence, insufficient prolactin production could potentially complicate breastfeeding rather than directly impacting the ability to become pregnant. Nonetheless, all aspects of reproductive health are intricately linked, and any hormonal imbalances can affect overall reproductive capability.