The functionality of the placenta may affect neonatal adiposity and fetal levels of key nutrients such as long-chain polyunsaturated fatty acids. Fetal macrosomia and its complications may occur even in adequately controlled gestational diabetic (GDM) mothers, suggesting that maternal glycemia is not the only determinant of fetal glycemic status and wellbeing. We studied in vivo the placental transfer of fatty acids (FA) labeled with stable isotopes administered to 11 control and 9 GDM pregnant women (6 treated with insulin). Subjects received orally 13C-palmitic, 13C-oleic, and 13C-linoleic acids and 13C-docosahexaenoic acid (13C-DHA) 12 h before an elective caesarean section. FA were quantified by gas chromatography and 13C enrichments by gas chromatography-isotope ratio mass spectrometry. The 13C-FA concentration was higher in total lipids of maternal plasma in GDM patients versus controls, except for 13C-DHA. Moreover, 13C-DHA showed a lower placenta/maternal plasma ratio in GDM patients versus controls and a significantly lower cord/maternal plasma ratio. Other FA ratios studied were not different between GDM and controls. A disturbed 13C-DHA placental uptake occurred in GDM patients treated with diet or insulin, while the latter also had lower 13C-DHA levels in the venous cord. The tracer study pointed towards an impaired placental DHA uptake as a critical step, while the transfer of other 13C-FA was less affected. Patients with GDM treated with insulin could also have a greater fetal fat storage, which may have contributed to the reduced 13C-DHA in the venous cord observed. The DHA transfer to the fetus was reduced in GDM pregnancies compared to controls. This might have an influence on fetal neurodevelopment and long-term consequences for the child.

The authors developed a method useful for home measurement of temperature, activity, and sleep rhythms in infants under normal-living conditions during their first 6 mos of life. In addition, parametric and nonparametric tests for assessing circadian system maturation in these infants were compared. Anthropometric parameters plus ankle skin temperature and activity were evaluated in 10 infants by means of two data loggers, Termochron iButton (DS1291H, Maxim Integrated Products, Sunnyvale, CA) for temperature and HOBO Pendant G (Hobo Pendant G Acceleration, UA-004-64, Onset Computer Corporation, Bourne, MA) for motor activity, located in special baby socks specifically designed for the study. Skin temperature and motor activity were recorded over 3 consecutive days at 15 days, 1, 3, and 6 mos of age. Circadian rhythms of skin temperature and motor activity appeared at 3 mos in most babies. Mean skin temperature decreased significantly by 3 mos of life relative to previous measurements (p = .0001), whereas mean activity continued to increase during the first 6 mos. For most of the parameters analyzed, statistically significant changes occurred at 3–6 mos relative to 0.5–1 mo of age. Major differences were found using nonparametric tests. Intradaily variability in motor activity decreased significantly at 6 mos of age relative to previous measurements, and followed a similar trend for temperature; interdaily stability increased significantly at 6 mos of age relative to previous measurements for both variables; relative amplitude increased significantly at 6 mos for temperature and at 3 mos for activity, both with respect to previous measurements. A high degree of correlation was found between chronobiological parametric and nonparametric tests for mean and mesor and also for relative amplitude versus the cosinor-derived amplitude. However, the correlation between parametric and nonparametric equivalent indices (acrophase and midpoint of M5, interdaily stability and Rayleigh test, or intradaily variability and P₁/P_ultradian) despite being significant, was lower for both temperature and activity. The circadian function index (CFI index), based on the integrated variable temperature-activity, increased gradually with age and was statistically significant at 6 mos of age. At 6 mos, 90% of the infants' rest period coincided with the standard sleep period of their parents, defined from 23:00 to 07:00 h (dichotomic index I < O; when I < O = 100%, there is a complete coincidence between infant nocturnal rest period and the standard rest period), whereas at 15 days of life the coincidence was only 75%. The combination of thermometry and actimetry using data loggers placed in infants' socks is a reliable method for assessing both variables and also sleep rhythms in infants under ambulatory conditions, with minimal disturbance. Using this methodological approach, circadian rhythms of skin temperature and motor activity appeared by 3 mos in most babies. Nonparametric tests provided more reliable information than cosinor analysis for circadian rhythm assessment in infants. (Author correspondence: elvirada@um. es )

Respiratory syncytial virus (RSV) is the main cause of low respiratory tract infections in infants under one year of age. In the 2023/2024 season, the monoclonal antibody nirsevimab was available to protect children from RSV, and Spain has become one of the first countries worldwide to implement this strategy. It is essential to evaluate the results of this first campaign and different characteristics of the immunized population in order to plan next campaigns, especially for countries that are going to include this immunization. Our coverage was high (91.5% for those born during the season and 88.3% globally). For those born during the season, only 4.9% preferred not to immunize at the maternity hospital, which meant an average delay of 27.45 days. We observed a lower coverage in the population of immigrant origin. There was a rapid pace of immunization, since for those born before the beginning of the campaign the mean to be immunized was 15.63 days, without differences between healthy and at-risk children. This allows immunization before the RSV season (90% of the catch-up children had been immunized on November 3). The average age at which all the immunized children have received nirsevimab was lower in healthy children compared to those with risk conditions (49.65 versus 232.85 days). For those born during the campaign, the average age was also lower in healthy children (3.14 versus 14.58 days). In conclusion, we consider that the implementation of the immunization strategy with nirsevimab in the Region of Murcia, Spain, has been a success.