Associations Between Hormonal Biomarkers and Cognitive, Motor, and Language Developmental Status in Very Low Birth Weight Infants

Development of neonatal high-risk preterm infants in comparison to full-term counterparts

Studies on preterm infants usually exclude high-risk neonatal infants with neurological problems. However, it is important to study high-risk preterm infants to better understand later developmental problems. Therefore, this cross-sectional study aimed to compare the cognitive, motor, language, and social-emotional development of high-risk preterm (PT) infants with infants born full-term (FT) with no biological vulnerabilities during early development (up to the first 15 months of age). The sample comprised 133 infants (54 born PT and 79 born FT) assessed in independent subsamples at 6-8 and 12-15 months of age, considering the corrected age for prematurity in the PT infants. Infant development (cognitive, motor, language, and social-emotional) was evaluated using the Bayley-III Scales. Medical charts were reviewed to obtain the clinical history. A multivariate analysis of variance and analysis of variance tests were performed to examine the differences between groups related to infant developmental indicators, controlling for age and socioeconomic variables. Although the PT infants performed significantly more poorly than their FT counterparts, the scores of the PT group were still within the normal range on all Bayley-III domains (cognitive, language, motor, and social-emotional) than their FT counterparts. The findings of the present study provide a better understanding of the developmental prognosis of high-risk PT infants and extend support for preventive intervention programs to improve early childhood development.

Associations Between Hormonal Biomarkers and Preterm Infant Health and Development During the First 2 Years After Birth

BACKGROUND

Testosterone levels have been used to examine infant boys' vulnerability to health and developmental problems, following the general theories of gender differences and the theory of extreme male brain of autism.

OBJECTIVES

As testosterone is a representative androgen hormone and is higher in preterm than full-term infants, we used this steroid to determine if hypothalamic pituitary hormones, testosterone, and cortisol, were related to physical growth, health, and development of very-low-birthweight (VLBW, BW < 1,500 g) infants.

METHOD

For this comparative longitudinal study, 40 VLBW infants were recruited from a neonatal intensive care unit of a tertiary medical center. Data were collected from medical record reviews, questionnaires, and assessments of infant development at 6, 12, and 24 months. We collected saliva at the three time points and measured hormones using enzyme-immunoassays.

RESULTS

General and generalized mixed models showed that a 1pg/ml increment of testosterone was related to a -0.42% decrease in body weight, a -0.18% decrease in length, and a -0.10% decrease in head circumference. Cortisol levels were not associated with any outcome variable. The interactions between testosterone and time on physical growth and socioemotional development also occurred.

DISCUSSION

Elevated testosterone levels can be a biological risk factor for poor infant growth and development. Theories about the effects of elevated prenatal testosterone could be useful in predicting health and developmental outcomes among VLBW infants. Research beyond the first 2 years will be needed as infants show more socioemotional and behavioral problems as they grow older.

Homocysteine-mediated gender-dependent effects of prenatal maternal depression on motor development in newborn infants

BACKGROUND

The present study aimed to determine whether there were gender differences in the effects of prenatal maternal depression on motor development in newborn infants, and further to explore the role of plasma homocysteine in the delayed motor development in male newborn infants following prenatal maternal depression.

METHODS

The term pregnant women within 37-42 weeks of gestation were assessed depressive symptoms by Hamilton Rating Scale for Depression. According to the gender of the newborn infants, all the subjects were divided into four groups: female control group (n = 45), male control group (n = 47), female depression group (n = 50), male depression group (n = 60). Motor development in newborn infants were assessed by Neonatal Behavioral Assessment Scale. Plasma homocysteine concentrations both in mothers and newborn infants were measured by enzymatic cycling assay.

RESULTS

There were the worse scores of the items of motor development and significantly higher plasma homocysteine concentrations  in the male newborn infants of depression group than those of the female depression group and female control group, male control group, respectively. Plasma homocysteine concentrations significantly correlated with the items of motor development in all newborn infants, including the depression group and control group.

LIMITATIONS

We should further explore homocysteine-mediated gender-dependent effects of prenatal maternal depression on motor development in newborn infants in the long-term follow-up.

CONCLUSIONS

Prenatal maternal depression could result in delayed motor development in male newborn infants, but not female newborn infants. Plasma homocysteine may mediate gender-dependent effects of prenatal maternal depression on motor development in newborn infants.