A significant amount of research over the years has been conducted in an effort to determine the effects of stress during pregnancy. While it would be helpful to have a straight forward answer to this question, conflicting results, weaknesses in research methodologies, and the intricate nature of the relationship between pregnancy and stress, make easy answers difficult.
The general hypothesis of those who believe that stress can negatively affect pregnancy is that difficult life events produce increased levels of the stress hormone cortisol. Since studies have shown that persistently high levels of cortisol in adults have been linked to negative health effects such as increased blood pressure and heart disease, the exposure of the fetus to high levels of cortisol must also have a detrimental effect. The belief is that too much cortisol in amniotic fluid affects the developing brains of foetuses. There are certainly studies that have shown that increased stress leads to premature birth and lowered birth weight. Other studies have also shown that increased stress during pregnancy is related to ADHD, learning problems and even schizophrenia later in life. One study even linked severe stress in the six months prior to conception to preterm birth. Given all this research and the headlines they generate, one begins to wonder whether the stress related to exposure to this research is having a negative effect!