The correlation of morphological and thrombotic villous arterial lesions with fetal Doppler echocardiographic measurements in the placentas of low-risk term pregnancies.

OBJECTIVE: Few studies have correlated the placental vasculature with fetal cardiac function other than umbilical artery Doppler assessment in low-risk pregnancies. We assessed the contribution of the placental vasculature to fetal echocardiographic parameters using histopathological and morphometric analyses of placental resistance arteries. STUDY DESIGN: Thirty-four low-risk singleton term pregnancies were assessed, including 24 thrombosis-negative cases (no/minimal gross and histological placental abnormalities) and 10 thrombosis-positive cases (histologically identified chorionic plate/stem vessel thrombosis). Fetal ventricular Doppler inflow velocities (E and A waves) and myocardial systolic (S'), early (E'), and late diastolic (A') tissue Doppler velocities were measured within three days before birth. The myocardial performance index (MPI') was calculated. Morphometric variables of placental stem villi arterioles (external diameter 10-150 µm) were examined, including the mean arteriolar density, total cross-sectional lumen area, and wall area/total vessel area (WA/TVA) ratio. RESULTS: The thrombosis-positive group had a higher umbilical artery pulsatility index and a lower tricuspid E'/A' ratio compared to the thrombosis-negative group. The WA/TVA ratio of stem villi arterioles was negatively correlated with tricuspid E, A, and S' velocities as well as the E/E' ratio (n = 34). The tricuspid MPI' was positively correlated with the total cross-sectional lumen area of stem villi arterioles (n = 34). CONCLUSION: We conclude that changes in several fetal echocardiographic parameters are associated with placental vascular histopathological and morphological characteristics in a low-risk population. Further studies are needed to assess whether fetal echocardiographic assessment is a promising prenatal predictor of placental vascular histopathological and morphological characteristics in the general population.

Seasonal variation in the international normalized ratio of neonates and its relationship with ambient temperature.

BACKGROUND: The morbidity and mortality rates due to cardiovascular events such as myocardial infarction are known to exhibit seasonal variations. Moreover, changes in the ambient temperature are reportedly associated with an increase in these events, which may potentially involve blood coagulation markers. Bleeding due to vitamin K deficiency in neonates, which is associated with high mortality and a high frequency of neurological sequelae, is more commonly observed during the summer season and in warm regions in Japan. To determine the presence of seasonal variation and the influence of ambient temperature on blood coagulation markers in healthy term neonates, we assessed the international normalized ratio (INR) values measured using CoaguChek XS. METHODS: We studied 488 consecutive healthy term neonates who were born at a perinatal center between July 2012 and June 2013. The INR values were measured using CoaguChek XS in 4-day-old neonates who received nursing care in the newborn nursery throughout the duration of hospitalization. The seasonal variations in the INR values and environmental effects on the INR were assessed. RESULTS: The mean monthly INR values peaked in July (1.13 ± 0.08), whereas the lowest values were observed in January (1.05 ± 0.08). Higher levels of INR were observed during the summer season (June to August) than during the winter season (December to February). Simple linear regression analysis indicated the presence of weakly positive but significant correlations between INR and outdoor temperature (r = 0.25, p < 0.001), outdoor relative humidity (r = 0.19, p < 0.001), and room relative humidity (r = 0.24, p < 0.001), and the presence of a significant negative correlation between INR and room temperature (r = -0.13, p = 0.02). Furthermore, multiple linear regression analysis showed that only outdoor temperature significantly influenced the INR. CONCLUSIONS: A seasonal variation in the INR values was observed among neonates, possibly due to the variation in ambient temperature. Even though the neonates received nursing care in the newborn nursery that was constantly air-conditioned, the outdoor temperature was the most influential factor on INR.

Fetal myocardial tissue Doppler indices before birth physiologically change in proportion to body size adjusted for gestational age in low-risk term pregnancies.

BACKGROUND: Few studies have investigated the relationship between myocardial tissue Doppler parameters and fetal size adjusted for gestational age and its trend has been controversial. AIMS: To investigate fetal cardiac function before birth using tissue Doppler imaging (TDI: indicated by the prime symbol (')) in low-risk term pregnancies by comparing the TDI parameters with gestational age-specific birth weight percentiles and z scores. STUDY DESIGN AND MEASUREMENTS: Interventricular septum, left and right ventricular myocardial peak early diastolic (E'), late diastolic (A') and systolic (S') velocities, E'/A' ratios, myocardial performance index (MPI') and umbilical artery pulsatility index were measured within three days before birth in 76 low-risk term pregnancies, including appropriate for gestational age (AGA, n=50), small for gestational age (SGA, n=10), and large for gestational age (LGA, n=16) subjects. RESULTS: Myocardial peak velocities showed higher in the LGA and lower in the SGA compared with the AGA group, and All S' positively correlated with birth weight (r=0.51-0.57). All z scores of S' demonstrated a positive correlation with birth weight z score (Spearman r=0.45-0.53). MPI' was significantly higher in the SGA and lower in the LGA compared with the AGA group. All MPI' negatively correlated with birth weight (r=-0.55 to -0.65). All z scores of MPI' showed a negative correlation with birth weight z score (Spearman r=-0.40 to -0.56). CONCLUSIONS: Fetal myocardial peak velocities and MPI' physiologically changed in proportion to body size adjusted for gestational age in low-risk term pregnancies.