General evaluation of periventricular-intraventricular hemorrhage in premature infants in mainland China.

OBJECTIVE: To explore the incidence and analyze the high risk factors of PIVH in premature infants in mainland China. MATERIALS AND METHODS: A total of 1122 premature infants at <37 weeks gestation were enrolled in this study. All the infants received intracranial ultrasound examinations within 1 week after birth, and the perinatal data were recorded to analyze the high risk factors for PIVH. RESULTS: The results showed that the incidence rate of PIVH was 55.2% in mainland Chinese population. Among these cases, mild degrees of PIVH accounted for 82.2% and severe degrees of PIVH accounted for only 17.8%. The most important risk factors related to PIVH were low gestational age, low birth weight, low Apgar score and ventilatory treatment, etc. CONCLUSIONS: It suggested that there were many high risk factors related to PIVH in premature infants and a screening cutoff point of 2000 g appeared to be more adequate for China.

Periventricular leukomalacia in premature infants in mainland China.

Periventricular leukomalacia (PVL) in premature infants is a major cause of mortality and disability. However, while China is the largest developing country, there is an absence of data concerning PVL. This study was carried out in order to explore the incidence rate and analyze the high-risk factors of PVL in premature infants, and to suggest a working protocol for the prevention of PVL in newborns at risk. The cohort prospective study included 921 premature infants < 37 weeks' gestation from January 2004 to July 2007. The study group was comprised of 271 premature infants with an ultrasound diagnosis of PVL and the control group was comprised of 650 premature infants who were submitted to the same evaluation protocol but did not show any echographic signs of PVL. The results showed that the incidence rate of PVL was 29.4% in China. High-degree PVL accounted for < 12% and > 88% of PVL was low-degree. The incidence rate was much higher when premature infants were accompanied by the following complications: low gestational age, low birth weight, prolonged rupture of membranes, chorionitis, mechanical ventilation, periventricular-ventricular hemorrhage, hypocapnia, and hyperlactacidemia. Severe complications that occur in premature infants also significantly increase the incidence of PVL. Antenatal corticosteroids can significantly decrease the incidence rate of PVL. This investigation provided a theoretical reference for the prevention of premature PVL.

The combined antenatal corticosteroids and vitamin K therapy for preventing periventricular-intraventricular hemorrhage in premature newborns less than 35 weeks gestation.

We prospectively evaluated whether combined antenatal corticosteroid and vitamin K administration have any benefit, over and above that of corticosteroid or vitamin K used alone, in reducing the frequency and the degree of PIVH in premature newborns less than 35 weeks' gestation. All of these 280 pregnant women were randomly allocated into five groups according to the in-patient sequence. Group A (vitamin K1 group) including 38 pregnant women (40 newborns) received antenatal intramuscular or intravenously injection of vitamin K1 10 mg per day for 2-7 days. Group B (single dose corticosteroid group) including 57 pregnant women (63 newborns) received antenatal intramuscular or intravenously injection of dexamethasone 10 mg per day for 1 day. Group C (two dose corticosteroid group) including 62 pregnant women (70 newborns) received antenatal intramuscular or intravenously injection of dexamethasone 10 mg per day for 2 days. Group D (combined using dexamethasone and vitamin K1) including 41 pregnant women (44 newborns) received dexamethasone 10 mg per day for 1 day and vitamin K110 mg per day for 2-7 days. Control group, including 82 pregnant women (87 newborns) were received neither dexamethasone nor vitamin K1 injection. The results showed PIVH was diagnosed in 17 of 40 (42.5%) in Group A, 34 of 63 (54.0%) in Group B, 36 of 70 (51.4%) in Group C, 14 of 44 (31.8%) in Group D, and 57 of 87 (65.2%) in control infants (p = 0.004). More infants in the control group had grade III or IV intracranial hemorrhage after birth (p = 0.049). After antenatal supplement of dexamethasone and vitamin K1, both the total incidence of PIVH and the frequency of severe PIVH decreased significantly. The total and severe incidence of PIVH in Group B (single doses dexamethasone) and Group C (two courses dexamethasone) there were no significant difference. It showed that after antenatal supplement of dexamethasone and vitamin K1, both the total incidence of PIVH and the frequency of severe PIVH decreased significantly, and combined antenatal corticosteroid and vitamin K administration have much benefit, over and above that of corticosteroid or vitamin K used alone.

[Level of vitamin K-dependent coagulation factors in premature infants and the influence of maternal antenatal administration of vitamin K1 on their activity].

OBJECTIVE: Infants less than 35 weeks of gestational age are susceptible to peri-/intraventricular hemorrhage (PIVH). This may be due in part to low concentrations of vitamin K-dependent coagulation factors. This study was conducted to determine the umbilical cord blood activities of vitamin K-dependent coagulation factors II, VII, IX and X in premature infants to understand whether preterm infants have absence status of these factors the changes of theses factors' activities in premature infants' umbilical blood after vitamin K(1) was given to mothers antenatally and the preventing effectiveness of PIVH after maternal antenatal supplement of vitamin K(1). METHODS: Pregnant women in preterm labor at less than 35 weeks of gestational age were randomly selected to receive antenatal vitamin K(1) intramuscular or intravenous injections 10 mg per day for 2 to 7 days (vitamin K(1) group), or no vitamin K(1) treatment (control group). Dexamethone was antenatally given to both groups of pregnant women routinely. Vitamin K(1) group had 44 infants and the control group had 133 infants. During the same period, thirty full-term neonates' cord blood samples were obtained to determine theses factors to compare with those from the premature infants. The cranial ultrasound was performed by a same physician to understand whether the neonates were complicated with PIVH and its severity. RESULTS: The levels of vitamin K-dependent coagulation factors in umbilical blood in control group were significantly lower than those in full-term infants' cord blood (P < 0.05). However, in vitamin K(1) group, supplement of vitamin K(1) antenatally could significantly increase activities of factors II, VII and X in preterm infants' cord blood (P < 0.05). The total occurrence rates of PIVH in vitamin K(1) group and control group were 31.8% and 52.6%, respectively, (P = 0.017), and the frequency of severe PIVH in vitamin K(1) group and control group was 2.3% and 12.0%, respectively (P = 0.057). CONCLUSION: Preterm infants have absence status of vitamin K-dependent coagulation factors. Administration of vitamin K(1) to pregnant women at less than 35 weeks of gestational age resulted in significantly improved activities of vitamin K-dependent coagulation factors II, VII, and X, and a significantly decreased frequency of PIVH and less severe hemorrhage in preterm infants.