Severe stress during pregnancy can harm the fetus, some previous studies show in both humans and animals. But can stress cause a miscarriage?
Previous research has suggested that stress is associated with a weakened blood supply to the placenta, affecting the fetus’s growth and development.
Obstetrician Anne Helbig works with fetal medicine as usual and is therefore used to meeting pregnant women who experience stress during pregnancy because they are concerned about their health. But it is the unhealthy stress that Helbig is most concerned about.
- Unhealthy stress is the stress you feel you can not cope with, leading to anxiety, depression, and post-traumatic stress disorder. When it is so severe and chronic, it is conceivable to affect the fetus.
Such unhealthy stress can, for example, come as a result of a traumatic life event, such as being informed that the child in the womb has severe abnormalities. Helbig, therefore, wanted to find out if such stress weakens the blood supply to the placenta and the fetus, a process that can potentially have severe consequences for the baby.
The results should prove to be surprising.
Increased blood supply
Women who have previously had children with severe abnormalities are particularly prone to stress, anxiety, and depression related to later pregnancies. Helbig and colleagues found no signs of impaired blood supply to the fetus in 74 pregnant women with such a history.
On the contrary, they found the opposite.
- Several goals for depression and stress turned out, but very surprising in an unexpected direction, says Helbig.
Both depression and intrusive thoughts about the child’s health in early pregnancy were associated with increased blood supply to the fetus.
An explanation for the finding may be that the woman’s body perceives the high-stress level at the beginning of the pregnancy as a sign of a poor supply of resources. The placenta can then compensate by becoming more significant.
The women with increased blood supply also had a relatively larger placenta. Helbig emphasizes that this is only one possible explanation and that more research is needed to confirm this.
No effect of acute stress
These results are part of Helbig’s doctoral dissertation. She used questionnaires to measure symptoms of anxiety, depression, and traumatic stress. Using advanced ultrasound, she measured the blood supply to the fetus in pregnant women who were exposed to various types of stress.
One of these groups of pregnant women had just been notified of severe abnormalities in the fetus. The women experienced very high-stress levels a few days after the bad news.
The degree of stress was mainly related to how serious the deviations were and whether there was uncertainty about the child’s prognosis.
To investigate the effect of this acute stress on the blood supply to the fetus, the researchers compared 86 of the pregnant women who had told about abnormalities in the fetus with 98 women with normal pregnancies.
The researchers did not see any reduction in the blood supply to the fetus in these women.
Helbig believes that the stress they experienced should have affected the measurements if it had any effect.
- This is extremely high stress, and we did not see anything.
However, she points out that this was acute stress and that chronic severe stress can affect the blood supply.
More accurate method
In these studies, the researchers used a direct measure of the fetus’ blood supply, which is more accurate than the indirect measures used in previous studies of stress during pregnancy. Nevertheless, they did not find a weakened blood flow, as previous studies have shown.
Helbig nevertheless believes that it is vital that those who work in the health care system are aware of pregnant women’s mental health.
- It is actually essential for the long-term health of both mother and fetus. Chronic stress is not suitable for people, whether they are pregnant or not.