Testosterone and Cortisol Levels in Infants

Duke University300 enrolled

Overview

Very low birth weight (VLBW) infants have more health and developmental problems than normal birth weight full-term infants. These problems are more common in males than female VLBW preterm infants. Male VLBW infants also experience less positive mother-infant interactions than females, especially when mothers are emotionally distressed. This is a significant problem because positive mother-infant interactions function as an important protective factor against the negative health and developmental outcomes associated with prematurity. The source of the vulnerability of male VLBW infants to health problems, suboptimal mother-infant interactions, and poor development goes beyond gender socialization differences and includes biological factors. Identification of infant and maternal biological markers/predictors of infant health and developmental outcomes could ultimately lead to interventions for VLBW preterm infants. The purpose of this study is to confirm that testosterone rather than cortisol is a more reliable marker/predictor of complications affecting infants' health outcomes, mother-infant interactions, and infant cognitive/motor/language developmental outcomes; and that male infants exhibit a higher sensitivity to testosterone levels than female infants. This longitudinal study will examine the associations of the steroid hormones, testosterone and cortisol, levels with infant health, mother-infant interactions, and infant cognitive/motor/language development ('infant development') in very low birthweight (VLBW, BW \< 1,500 g) preterm (gestational age \< 32 weeks gestation) infants after adjusting for maternal physical and mental health state, infant socioemotional and behavioral development, and characteristics of infants and mothers. Concurrent and repeated measurement of testosterone and cortisol levels both in infants and mothers will be conducted through infancy and early childhood (at birth, 40 weeks postmenstrual age, 12 and 24 months corrected age).

Study Type

OBSERVATIONAL

Enrollment

300

Conditions

Infant, Premature

Eligibility

Sex: ALLMin age: 1 MinuteMax age: 72 Hours

Medical Language ↔ Plain English

Inclusion Criteria: * Neonates will be included if they are less than or equal to 32/0 weeks gestational age at birth and have a birth weight \< 1500 grams. * Mothers will be included if they are (1) older than 15 years, (2) able to communicate in English or Spanish, (3) primary caregivers of the newborn. Exclusion Criteria: * Neonates will be excluded if they (1) are born \> 32/0 weeks GA, (2) weigh more than 1,500 grams at birth, (3) have congenital abnormalities, (2) will be discharged before day 7 of life, (3) have a positive urine drug screen, or (4) are being placed for adoption after discharge from the hospital. * Mothers will be excluded if they have (1) narcotic or injection drug dependence or (2) a documented serious health (e.g., cancer or HIV positive) or psychological (e.g., schizophrenia) problem.

Outcomes

Primary Outcomes

measurements of maternal and neonate/infant testosterone and cortisol (T&C) levels from admission through 24-months of life to determine associations of T&C with health outcomes of neonates and infants between genders

The levels of testosterone and cortisol will be measured and compared with health outcomes of neonates/infants, at birth, 40 weeks postmenstrual age (PMA), 6, 12, and 24 months corrected age (CA) after controlling for covariates. The latter include maternal psychological state, infant temperament, and characteristics of mothers (age, race, body mass index \[BMI\], education, and marital status).

Time frame: Admission through 24 months of life

video recorded interactions at 12- and 24-months to determine associations of testosterone and cortisol levels with quality of mother-infant interactions between genders during infancy

The levels of testosterone and cortisol will be measured and compared with quality of mother-infant interactions at 12- and 24-months CA after controlling for the covariates.

Time frame: 12- and 24-months of age

standard infant testing at 12- and 24-months of age to determine associations of testosterone and cortisol levels with infant cognitive/motor/language development between genders during infancy

The levels of testosterone and cortisol will be measured and compared with infant development at 12- and 24-months CA after controlling for the covariates and mother-infant interactions.