Study explores link between prenatal stress during COVID-19 pandemic and negative neurodevelopmental outcomes in infants

By Neha MathurSep 12 2022Reviewed by Aimee Molineux

In a recent study published in the journal Infancy, researchers pursued evidence of prenatal stress during the coronavirus disease 2019 (COVID-19) pandemic, which could have negatively affected infants.

Background

The COVID-19 pandemic served as an ideal time to examine fluctuations in prenatal stress levels of expecting women during the already-difficult period of pregnancy. Emotional dysregulation in early childhood is a transdiagnostic indicator of later-developing psychopathology.

Therefore, several research studies have examined whether perceived stress during the prenatal period causes emotional dysregulation in infants. However, retrospective studies documented the past prenatal stress measured at a single time point. Moreover, despite the correlation between prenatal stress and infant development evidenced in the prior literature, the mechanisms driving these, and the levels or patterns at which prenatal stress becomes deleterious, have remained unknown.

About the study

In the present study, researchers used the ecological momentary assessment (EMA) method to gather intensive stress data via text messages. This data better captured the gestational experience than retrospective questions about past stress measured at a single time point.

They determined three indicators of prenatal stress using EMAs – baseline stress, average stress, and the lability of stress. They determined their relation to three-month-old infants' socioemotional development. The lability of stress, the extent to which stress levels fluctuate over time during pregnancy, is the most useful predictor of adverse neurodevelopmental outcomes with important implications for prevention.

The team made the baseline assessment via an online tool called REDCap between four and 22 weeks of gestation. Mothers completed the 10-item version of the perceived stress scale (PSS-10). For the average prenatal stress assessment, they used up to four times per day with the same four items of the PSS (PSS-4). They examined the correlations between EMA timing and stress levels during the 14-week EMA period.

For stress lability, the researchers employed the Infant Behavior Questionnaire-Revised—Very Short Form (IBQ-R-VSF), focusing on the negative affect dimension, consisting of 12 items from three subscales: Sadness, Distress to Limitations, and Fear. The mother completed the IBQ-R-VSF at the three-month assessment using a seven-point scale ranging from one to seven, with one indicating 'never' to seven indicating 'always'. The team summed individual item response scores and calculated their mean, where higher scores indicated more negative affect on infants.

The team used a t-test to determine whether baseline stress levels differed by the timing of study enrollment relative to the onset of the pandemic, i.e., March 20, 2020. The study participants were urban U.S. women aged 18 years or above with access to a smartphone and wireless internet. They were recruited between nine and 20 weeks of gestation and followed through their child's second birthday.

Study findings

The current study analyzed prenatal and infant outcome data of 72 women and 39 female and 33 male infants. The infants' average age at the outcome was 3.45 months. Nearly 39% of mothers' completed their EMAs before March 20, 2020, and ~61% of mothers' EMAs on/after March 20, 2020.

The primary study finding was that the baseline stress did not differ depending on whether mothers completed the EMA before or during the COVID-19 pandemic. Clearly, the EMA timing did not correlate with the average stress and stress lability. Several prior studies have found significant effects of COVID-19 on mental health; hence, this was an unexpected finding. A possible explanation could be that the current study population was highly educated, middle to upper-class women. They had more financial and social support and could better protect themselves from COVID-19. Overall, they had no fears surrounding job loss, lack of social support, and disease exposure.

The current study examined expecting mothers' emotional dysregulation by statistically capturing naturally-occurring variations in stress during pregnancy from one day to the next across multi-day reports over 14 weeks during pregnancy using mean squared successive differences (MSSDs). The authors controlled the proportion of EMAs completed during the pandemic. Surprisingly, mothers who completed more EMAs during the pandemic reflecting spending more time pregnant during the COVID-19 pandemic reported lower levels of negative affect in their infants. This finding suggested that these women better adapted to the demands of a changing environment, which may have had a positive effect on infant development.

The current study did not estimate postnatal stress lability and the mechanisms underlying stress lability. Future research should examine why large fluctuations in stress may matter for infants' socioemotional development in the prenatal period. Also, one must exercise caution when interpreting the association between prenatal stress lability and infant negative affect.

Conclusions

The current study demonstrated how daily fluctuations in an expecting mother's stress in pregnancy during the COVID-19 pandemic might have influenced infant neurodevelopmental outcomes. Thus, the study emphasized the infant development trajectories, focusing on underlying biological mechanisms, and repeated measurement of constructs.

Future research should examine these stress variations and their correlation to infant outcomes using a larger study sample than used in the current study. Since depressive symptoms and anxiety might have unique, additive effects on early infant outcomes, future studies should also consider these aspects, particularly given the benefits of interventions related to these conditions in enhancing maternal well-being.