Introduction
Accumulating evidence has shown that prenatal and early life
psychological stress and stress correlates, like maternal depression and
anxiety, are linked to an increased risk of respiratory disorders
including wheeze and asthma1 in the offspring.
Psychological stress can affect the individual biology, progression, and
management of respiratory disease throughout the
lifespan2, 3. Maternal psychological functioning has
been linked to the alteration of the immune system and lung
development4 prenatally and in early childhood. Both
prenatal and postnatal maternal psychological functioning is associated
with higher risk of allergy, asthma, and wheezing development in
infants5. The effects of prenatal and postnatal
maternal stress have been examined independently from one another but
the influence of the timing of exposure during critical periods of
development has not been completely elucidated6-8.
A few recent studies have examined the impact of prenatal and postnatal
maternal distress on childhood risk of atopic and respiratory
disease9-11. Van der Leek et al11reported significant associations between maternal prenatal, recurrent
postpartum, and late onset postpartum distress and higher risk of atopic
dermatitis at age 5 years11. Prenatal maternal
distress and late onset postnatal distress were also associated with
asthma at 7 years of age11. Brew et
al9 examined the association between maternal
depression or anxiety during different exposure periods (pre-conception,
pregnancy, postnatal, or current) and childhood asthma development. They
did not identify a critical exposure period but rather reported that
chronic exposure to maternal depression and anxiety is associated with
offspring asthma. Ramratnam et al12 concluded that
maternal stress and depression in the first 3 years were positively
associated with respiratory illnesses and a
moderate-wheeze-low-atopy-phenotype12.
Growing evidence has also demonstrated that critical windows of
vulnerability may differ by sex of the offspring10.
Our group reported stronger associations between higher prenatal
maternal stress and childhood wheeze in males while the association
between postnatal maternal stress and wheeze was stronger among
females13. Similarly, Lee and colleagues reported that
males were more vulnerable to stress during the prenatal period and
females were more impacted by postnatal and cumulative maternal stress
when examining asthma risk10.
While the majority of these studies have been conducted in high-income
countries, maternal stress and depression is of particular concern in
low- and middle-income countries given its high prevalence and the
limited resources for its diagnosis and
management14-16. Furthermore, studies have shown the
prevalence of asthma has increased worldwide, especially in
non-industrialized countries17, 18. Understanding the
impact of timing and duration of symptoms of maternal psychosocial
distress during and post pregnancy and the development of childhood
respiratory disease would fulfill a research gap. We leveraged existing
data from an established population-based prenatally enrolled
longitudinal cohort in Mexico City. We examined the association between
maternal depression, assessed during pregnancy and postnatally, and the
risk of respiratory disease in early childhood. We also examined whether
these effects differed by child sex.