Quasi-Experimental study of effects of lighting on rest, activity and melatonin in postpartum women

Cristina Furtado Volcov,Jennifer Hocking,Miriam Harumi Tsunemi,Ariane Ferreira Machado Avelar,Kelly Pereira Coca,Eliana Moreira Pinheiro,Fernanda Gaspar Do Amaral

doi:10.1590/0034-7167-2020-1064

Abstract

to compare the parameters of the activity/rest cycle of early postpartum breastfeeding women under a controlled and uncontrolled long wavelength ray light regimen. quasi-experimental study with breastfeeding women and their babies during postnatal rooming-in, São Paulo, Brazil. Participants were allocated to either an experimental (intervention) or a comparison group. The intervention involved exposure of the woman in a controlled room with artificial long wavelength ray light at night. Each woman's level of 6-sulfatoxymelatonin at 24 hours and activity/rest times was analyzed. the mean activity/rest times of women in the experimental and comparison groups were similar. The mean percentages of total load of 6-sulfatoxymelatonin during the day and night were similar (p=0.09). At 24 hours, the experimental group presented a significantly lower mean percentage of total load compared to the comparison group (p=0.04). women who stayed in the room with long-wavelength artificial light showed no difference in activity/rest and 6-sulfatoxymelatonin levels in the early postpartum period.

Highlights

The sleep-wake cycle is mainly controlled by the endogenous biological clock that determines circadian fluctuations in a series of physiological systems[1]
Other observed effects include increased presence of anxiety-related symptoms[26], risk for depression among truck drivers[27]; and increased fatigue, reduced vigor and cognition in airplane pilots and flight controllers[28]. In light of these mixed findings it would be helpful to understand more about the effect of exposure to artificial lighting commonly used in maternity hospitals at night, with a view to improving care for the mother-baby breastfeeding dyad in the postpartum period
Those who met the established criteria were invited to participate in the study After reading the study information and signing the consent form, the researcher interviewed each woman to identify the following variables: sociodemographic data, clinical history, obstetric data and newborn data

Summary

INTRODUCTION

The sleep-wake cycle is mainly controlled by the endogenous biological clock that determines circadian fluctuations in a series of physiological systems[1]. Changes in the woman’s circadian cycle in the postpartum period are characterized by a process called masking, in which the body is influenced by allowing for greater flexibility in order to adjust its sleep cycle to that of the newborn[6,7] This occurs in response to women seeking to mimic their newborn infant’s ultradian sleep cycle in order to meet the frequent care demands required by the infant[6,8]. Other observed effects include increased presence of anxiety-related symptoms[26], risk for depression among truck drivers[27]; and increased fatigue, reduced vigor and cognition in airplane pilots and flight controllers[28] In light of these mixed findings it would be helpful to understand more about the effect of exposure to artificial lighting commonly used in maternity hospitals at night, with a view to improving care for the mother-baby breastfeeding dyad in the postpartum period

METHODS

RESULTS

DISCUSSION

Study limitations

CONCLUSIONS