This is the conclusion reached by the authors of a review published recently in the journal The Lancet Psychiatry. Pregnancy depression most commonly affects women in the last trimester of pregnancy and immediately after the birth of the baby. The statistics are alarming - 1 in 5 women suffer from the disorder, and with them entire families. It is characterised by a lowered mood, a feeling of helplessness and a lack of motivation to be a mum. Pregnancy depression can be caused by external (e.g. bereavement) and internal (disturbances in the concentrations of relevant neurotransmitters) factors.
A team from Imperial College London showed that depression or anxiety can reduce levels of the enzyme that breaks down the 'stress hormone' i.e. cortisol, thereby causing greater fetal exposure to this substance. The fetus may also undergo epigenetic changes under stress, with the amount of underlying DNA remaining the same but expression being altered, which can cause mental health disorders during childhood.
Previous research has been based on an analysis of female patients from affluent countries, but the study by the London researchers points out that the problem may be much more common in low- or middle-income countries. Several factors contribute to this, the researchers mention in their paper.
In poor countries, women are much more likely to experience violence from their partners and have less social support (in family, friends). There is also a much higher rate of unplanned pregnancies in such countries than in affluent countries. Access to treatment, nutrition is worse, and various infections are more common. Particularly in countries where access to primary healthcare is difficult, physical health is taken care of first and mental needs only second (if at all). under such conditions, it is extremely difficult to have the quiet time needed to mentally prepare for childbirth. On the other hand, it is much easier to suffer chronic stress, which plays a significant role in the development of pregnancy and postnatal depression.