Background:

Recent research has found that newborns, whose mothers present a mood disorder, show at this age a profile of dysregulation characterized by an impaired performance according to the Brazelton Neonatal Behavioral Assessment Scale, indeterminate hipersomnia high levels of stress related hormones (norepinephrine and cortisol) right frontal EEG activation deficient responsivity to facial expressions and impairment of sympathetic response characterized by lower vagal tone. Newborns from mothers who were depressed during pregnancy show to be more irritable, more difficult to console, and have less developed motor tone than newborns from nondepressed mothers. The mother’s behavior, related to the newborn, is characterized by two predominant interaction styles: withdrawn or intrusive, which seem to have differential negative effects on their infants, due to inadequate stimulation and arousal modulation. The mother’s mood and anxiety disorders may affect the newborn due to exposure of the fetus to the maternal biochemical imbalance.

Because the longer exposure to an intrauterine environment marked by high levels of cortisol and norepinephrine was likely to result in less optimal outcomes, the newborns of mother who were depressed only at the beginning of pregnancy were likely to show more optimal profiles than those of mothers reporting symptoms of depression and accompanying biochemical imbalances at the middle and at the end of pregnancy.

Studies on prepartum health behaviors provide evidence for the indirect effects of maternal depression on the prepartum environment. Depressed mothers are less likely to seek prepartum care and are more likely to smoke, drink, and use cocaine during pregnancy than non depressed mothers.

Objective:

To compare the systems of behavior organization of those infants born from high neonatal risk mothers with or without mood disorder.

Method:

An observational, analytical and longitudinal case-control study was designed. A sample of 53 women, 18 to 40 years old and with a 16-35 weeks pregnancy was selected for this study. From this sample, 24 women did not have a mood disorder diagnosis and had a mean age of 27.7 ± 5.3 and 29 women had this diagnosis and a mean age of 30 ± 6.7 years. Mean gestational age of infants at birth was 39.4 ± 1.3 and 39.1 ± 1.2, respectively. This study was carried out from April 2003 to June 2004. Women participated in this study after signing their acceptance. The Neonatal Behavioral Assessment Scale (NBAS), an instrument used to detect the presence of alterations during the first 2 months of life of newborns, was applied to 53 infants at two different moments: 3 days and 27-30 days after birth. Women were assigned to the case (diagnosis of mood disorder) or control group (without mood disorder) after the application of the Edimburgh Postnatal Depression Scale (EDPS) and the structured interview for axis I and II of the DSM-IV. ANOVA tests were used for comparisons between the study groups (cases and controls) as independent variables, and the pretest and post test change, as the dependent variables. Initial values, the interval in days between the evaluations and gestational age were considered covariables in the analysis. This analysis was done for each of the 6 clusters or segments of the NBAS which are: social interaction, motor system, state organization, state regulation, autonomic system, and the cluster of supplementary items. These were also considered for the total score.

Results:

During the first evaluation, all infants performed satisfactorily, a fact that indicates that at birth they were in good conditions for their future development. When reviewing changes of the 6 analyzed clusters, the only differences found were in motor maturity. Infants from depressed mothers showed a slight difference (adjusted mean 0.971 ± 2.6 points) when compared with babies from non-depressed mothers (adjusted mean 2.033 ± 2.6 points) [F(1,49)=3.83,p=0.05]. The rest of the segments from the NBAS did not show a statistical difference. All results were favorable in all clusters for mothers without mood disorder, independently from the covariables.

Conclusion:

Behavior organization of infants born to women with mood disorder tends to show delayed motor maturity. Even though we did not find evidence of delayed development in the other clusters, a trend could be observed. Decreased motor tone and lower activity levels, lethargy, and stress behaviors were noted in the infants of depressed mothers, suggesting that infants were floppy, relatively unresponsive, and reminiscent of newborns who are small for date. This behaviors might contribute to the later difficulties noted in the interactions of depressed mothers and their infants.

It is important to further study the effects of maternal depression in the development of behavior organization in newborns. It is also important to study the biochemical disturbances in the mother secondary to her depression, and their effect in the biochemical balance of her neonate. Cortisol has a great influence on the cerebral development and it is associated to the inhibition of neurogenesis in hypothalamus. This inhibition perhaps may be the cause of depression in the newborn. The mother’s anxiety during pregnancy may have a great influence on the behavior of the newborn.

In this study, the mother was undergoing a high risk pregnancy, with some previous abortions, low pregnant age and other perinatal risks. Under this conditions, mothers are likely to present psychological distress.

        · abstract in Spanish     · text in Spanish     · Spanish ( pdf )