Previous studies have demonstrated that a light-dark cycle has promoted better sleep development and weight gain in preterm infants than constant light or constant darkness. However, it was unknown whether brief light exposure at night for medical treatment and nursing care would compromise the benefits brought about by such a light-dark cycle. To examine such possibility, we developed a special red LED light with a wavelength of >675 nm which preterm infants cannot perceive. Preterm infants born at <36 weeks’ gestational age were randomly assigned for periodic exposure to either white or red LED light at night in a light-dark cycle after transfer from the Neonatal Intensive Care Unit to the Growing Care Unit, used for supporting infants as they mature. Activity, nighttime crying and body weight were continuously monitored from enrolment until discharge. No significant difference in rest-activity patterns, nighttime crying, or weight gain was observed between control and experimental groups. The data indicate that nursing care conducted at 3 to 4-hour intervals exposing infants to light for <15 minutes does not prevent the infants from developing circadian rest-activity patterns, or proper body growth as long as the infants are exposed to regular light-dark cycles.

No abstract

No abstract

ExT was very effective in improving hyperleukocytosis and may have had favorable effects on respiration.

No abstract

This literature review was conducted to provide better counsel to pregnant women who erroneously took angiotensin receptor blockers (ARBs) during the second and/or third trimesters regarding infant outcomes. Information was available on 83 fetuses in 34 literature reports, including one that we encountered recently. Fourteen pregnancies were terminated, and six were unknown regarding status of amniotic fluid volume (AFV). Fifty-eight and five fetuses did and did not show oligohydramnios, respectively, after being exposed to ARBs. Of the 58 fetuses that presented with oligohydramnios, 57 were exposed to ARBs at gestational week (GW) ⩾ 20, and 19 exhibited resolution of oligohydramnios 1-6 weeks after cessation of ARBs. The 24 mothers without oligohydramnios at delivery ceased taking ARBs earlier (GW of 26.8 ± 5.1 vs. 31.8 ± 4.0, respectively, P = 0.000) and had longer duration of gestation after cessation of ARBs (8.4 ± 5.2 vs. 0.7 ± 2.3 weeks, respectively, P = 0.000). The mothers without oligohydramnios also had better outcomes in terms of favorable infant outcomes (63% (15/24) vs. 15% (6/39), respectively, P = 0.000) and infant mortality rates (13% (3/24) vs. 56% (22/39), respectively, P = 0.001) than the 39 with oligohydramnios. Thus, a favorable outcome may be feasible if the fetuses are not indicated for prompt delivery at presentation and exhibit normal AFV or resolution of oligohydramnios after cessation of ARBs. Although the prevalence rate of oligohydramnios was high in this study, it may have been due to publication bias. A prospective study suggested a lower prevalence rate than that reported in the present study.

A number of studies have been made on the sleep characteristics of children born preterm in an attempt to develop methods to address the sleep problems commonly observed among such children. However, the reported sleep characteristics from these studies vary depending on the observation methods used, i.e., actigraphy, polysomnography and questionnaire. In the current study, to obtain reliable data on the sleep characteristics of preterm-born children, we investigated the difference in sleep properties between 97 preterm and 97 term toddlers of approximately 1.5 years of age using actigraphy. Actigraphy units were attached to the toddlers’ waists with an adjustable elastic belt for 7 consecutive days, and a child sleep diary was completed by their parents. In the study, we found that preterm toddlers had more nocturnal awakenings and more daytime activity, suggesting that preterm-born children may have a different process of sleep development in their early development.

Our recent study on full-term toddlers demonstrated that daytime nap properties affect the distribution ratio between nap and nighttime sleep duration in total sleep time but does not affect the overall total amount of daily sleep time. However, there is still no clear scientific consensus as to whether the ratio between naps and nighttime sleep or just daily total sleep duration itself is more important for healthy child development. In the current study, to gain an answer to this question, we examined the relationship between the sleep properties and the cognitive development of toddlers born prematurely using actigraphy and the Kyoto scale of psychological development (KSPD) test. 101 premature toddlers of approximately 1.5 years of age were recruited for the study. Actigraphy units were attached to their waist with an adjustable elastic belt for 7 consecutive days and a child sleep diary was completed by their parents. In the study, we found no significant correlation between either nap or nighttime sleep duration and cognitive development of the preterm toddlers. In contrast, we found that stable daily wake time was significantly associated with better cognitive development, suggesting that sleep regulation may contribute to the brain maturation of preterm toddlers.