Anyone who has had a baby that cried excessively can probably attest to the stress and anxiety this can cause.
Obviously people's tolerance for crying babies differs, however excessively crying has been defined as crying for more than 3 hours a day on at least 3 days a week over a period of 3 weeks or more, when that crying is not associated with hunger or physical pain.
A study just published this week by researchers at the Institute of Clinical Psychology and Psychotherapy, at the Technical University of Dresden, Germany looked at 306 expectant mothers and followed them from just after they became aware they were pregnant until 16 weeks after the birth of their child. Two of the factors they measured was the mothers level of anxiety and depression both before and after the birth of the baby. Firstly they found that just over 10% of the mothers reported excessive crying in their infants according to the definition above.
What they discovered was that there was a significant link between the level of anxiety the mother experienced before the birth and the chance of the baby engaging in excessive crying in the 16 weeks after birth. Additionally there was no link with depression and excessive crying.
Another study published in the Journal 'Pediatrics' on the 6th of January this year, by a team of scientists from Finland showed that excessive crying in babies has significant links to later behavioural problems for the child and also (not surprisingly) increased stress for both the mother and father as the child grows.
Mothers who suffer from any form of anxiety during pregnancy are 3-7 times more likely to have a baby that cries excessively than the rest of the population of mothers to be. The researchers recommend early identification, monitoring and treatment of anxiety in all mothers to be.
Korja, P., etal (2014) Preterm Infant's Early Crying Associated With Child's Behavioral Problems and Parents' Stress. Pediatrics 2014; 133:2 e339-e345; published ahead of print January 6, 2014, doi:10.1542/peds.2013-1204
Petzoldt, J., etal (2014) Maternal anxiety disorders predict excessive infant crying: a prospective longitudinal study. Archives of Disease in Childhood. June 2014 doi:10.1136/archdischild-2013-305562