Women under stress are thrice as likely to miscarry during the first three weeks of pregnancy as revealed by elevated urinary cortisol levels. The study is the first of it's kind to have established a link between increase in cortisol levels to pregnancy loss at an early stage.
Cortisol is a hormone that is released in response to stress. Urinary levels of this hormone serve as a reliable stress indicator. Nearly 61 pregnant women in Guatemala were taken up for the study and were subjected to urine analysis thrice in week for 1 year (even before they became pregnant). This allowed measurement of baseline level of cortisol on an individual basis.
It has been established from previous studies that 31 to 89% of conceptions result in miscarriage. A majority of the clinical studies are conducted around the 6 week of pregnancy when women notice that they are pregnant. The miscarriages that occur during the first three weeks of conception are however largely ignored. Infact a majority of the miscarriages occur at this stage, which often go unnoticed.
Among the study participants aged between 18 and 34 years, the incidence of miscarriage was as high as 90% in women with elevated levels of cortisol in comparison to 33% miscarriage among women with normal hormone levels. It is believed that high cortisol levels may signal the body that conditions are hostile for preservation and continuation of pregnancy, resulting in miscarriage.
'Maybe increased cortisol is understood by the body as a cue that the context is uncertain, changing, or the quality of the environment is deteriorating. The body's response is to stop any extra activity and go back to its most basic functions,' said Nepomnaschy, one of the researchers involved in the study.
It is unclear whether cortisol elevation induces miscarriage directly or through other signal transduction mechanisms. The results of the present study highlight the importance of stress in early pregnancy loss. More studies are indicated to establish a definitive association between miscarriage and stress, through a large population based study.