In the mean time...
Cortisol levels and very early pregnancy loss in humans
Maternal stress is commonly cited as an important risk factor for spontaneous abortion. For humans, however, there is little physiological evidence linking miscarriage to stress. This lack of evidence may be attributable to a paucity of research on maternal stress during the earliest gestational stages. Most human studies have focused on “clinical” pregnancy (>6 weeks after the last menstrual period). The majority of miscarriages, however, occur earlier, within the first 3 weeks after conception (≈5 weeks after the last menstrual period). Studies focused on clinical pregnancy thus miss the most critical period for pregnancy continuance. We examined the association between miscarriage and levels of maternal urinary cortisol during the first 3 weeks after conception. Pregnancies characterized by increased maternal cortisol during this period (within participant analyses) were more likely to result in spontaneous abortion (P < 0.05). This evidence links increased levels in this stress marker with a higher risk of early pregnancy loss in humans.
Snip...Cortisol production rises in response to energetic, immunological, and psychosocial challenges (47, 48). Thus, cortisol increases could serve as a physiological cue to women’s bodies that conditions for reproduction are deteriorating.
Snip...Our finding of an association between increased maternal cortisol and higher risk of miscarriage within the first 3 weeks of conception, together with the failure of previous research to find such an association later during gestation (23), suggests that pregnancy may be particularly sensitive to maternal stress during the placentation period.
Pretty interesting, eh?
Cortisol in Blood
Cortisol has many functions. It helps the body use sugar (glucose) and fat for energy (metabolism), and it helps the body manage stress. Cortisol levels can be affected by many conditions, such as physical or emotional stress, strenuous activity, infection, or injury.
Normally, cortisol levels rise during the early morning hours and are highest about 7 a.m. They drop very low in the evening and during the early phase of sleep. But if you sleep during the day and are up at night, this pattern may be reversed. If you do not have this daily change (diurnal rhythm) in cortisol levels, you may have overactive adrenal glands.
Another...Cortisol Tests
Cortisol levels normally rise and fall during the day in what is called a diurnal variation, so that cortisol is at its highest level between 6-8 A.M. and gradually falls, reaching its lowest point around midnight.
It doesn't "shoot up" at all under "normal" circumstances.