We know that roots of many mental health problems in adult age group can be traced to childhood events, relationships and difficulties.Many physical disorders in adult life also have their origins in early life (= ‘foetal origin of adult disorders’).
Is extreme low birth weight ( less than 1000g) a risk factor for mental disorders in adult life?
Ryan J. Van Lieshout and team from McMaster University, Canada studied the oldest followed up cohort of Extremely Low Birth Weight (ELBW) infants in the world. Participants were followed up to their early 30s. Control participants had normal birth weight. Structured diagnostic interview (MINI) was administered by assessors blind to birthweight status. Assessment focused on 9 diagnostic groups. Low Birth Weight survivors who had birth weights less than 10th percentile for gestational age were classified as SGA ( Small for Gestational age) and the remainder were born at an appropriate weight for gestational age as AGA ( appropriate for gestational age).
Of the 397 ELBW infants recruited at birth 45% survived to leave hospital and were followed up. 60% of this group participated in the psychiatric assessment.
In unadjusted models , ELBW groups had higher odds for any current non–substance use disorder (OR = 2.47; 95% CI, 1.19–5.14) but lower odds of any current alcohol or substance use disorder (OR = 0.38; 95% CI, 0.17–0.86). Adjusted models also support this relationship. ELBW with SGA showed same relationship i.e. higher odds of any non substance use disorder, with a larger OR of 3.82.
What about the risk among those who received antenatal steroids? (ACS group): The ELBW and ACS group had higher odds of a current psychiatric disorder and 3 times the odds of a current diagnosis of GAD, were 6 times more likely to have social phobia, and had 11 times the odds of having ADHD. Data is also suggestive of the possibility of a dose response relationship here. The protection from substance use see in others disappeared if they have had antenatal steroids. Steroids that cross the placenta might be influencing the glucocorticoid receptors in limbic region, amplifying/generating the psychiatric effects.
The study show that the odds of people born at ELBW having a clinically significant psychiatric problem were twice as high as those of NBW control participants.Thye have lower odds of having a current or lifetime alcohol or substance use disorder.
Why a less chance of having sub use disorder in this group? It is possible that shy/risk avoidant personality style and higher parental monitoring in childhood could explain some of this. Prenatal factors associated with preterm birth and stressful earlylife experiences may explain the increased prevalence of non substance related disorders. As in these situations, complex and multifactorial factors are likely to be in action.
Limitations: Sample attrition over years is significant. Sample size may limit the power to detect differences in multiple comparisons.
Comments: extremely low birthweight is associated with different profile of mental health. Antenatal steroid use is a life saving intervention, but this might be associated with an increase of psychopathology in adult life.
Summary of the article:
Mental health of extremely low birth weight survivors in their 30s.Van Lieshout RJ, Boyle MH, Saigal S, Morrison K, Schmidt LA.Pediatrics. 2015 Mar;135(3):452-9