Relationship And Significance Of Serum Cortisol,cox-2and PG In Neonatal With Preterm

Objective:Recently,the birthrate of preterm is incrasing.With the develo-pment of the NICU, the survival rate is significantly inproved.However,theorgans of premature infants do not mature enough,and the occurrence ofcomplication affects the quality of their life forward seriously. It is critical thatprevent preterm effectively for reducing the birthrate of preterm andimproving prognosis.Hence,it is urgent to solve the problem that how toprevent the occurrence of preterm.First we must know the reason ofpreterm.Currently the reasons known include:infection,age of the mother,uterine factors,pregnant complications,the environment of the social life,statement of the economy and so on.Second,we should make clear themechanisms of the preterm with the corresponding diseases.Althoughprostaglandin leads to preterm at last in public,the regulation is not knowncompletely at present.Studies believe that the parturition is a complex andcomprehensive result,so we must consider all kinds of factors.Recently,bystudy the model of sheep and mammal, Challis et.al.find that the activity ofthe HPA of the fetal is the central parturition mechanism.The activity of fetalHPA directly results to the increase of cortisol in fetuses.Then cortisol directlyaffects the expression of placental prostaglandin synthetase,which leads to theincrease of prostaglandin(PG).PG can make cervical soft, make uterinecontraction so that start the parturition. Therefore,we could infer cortisol as aninducing factor of prostaglandin synthesis promotes the synthesis of PG tostart the parturition indirectly. Many factors affect the synthesis of cortisol,anddifferent pathogenies lead to different expression of cortisol.Especially at thestate of stress,it may be secreted much. Cortisol as a stress hormone is aimportant role in the delivery by the cascade reaction which can be describedcortisol-prostaglandin synthetase(cox-2)-prostaglandin(PG).Hence,we can understand the role of secretion in pregnancy through detecting the expressionlevel of cortisol in newborn blood,so that provide a new way for effectivelypreventing preterm.In addition,rational evaluation is an important way toimprove the prognosis in long term while prevention effectively isfundamental to deduce the birthrate of preterm.Some researchers pointed outthat the level of cortisol before and after affected the expression of thenewborn's nerve fiber in brain key regions.These regions include hippocampusand some related remember.Furthermore,PG plays a role in remaining the fetalarteriosus ductus not closed so provides oxygen rich blood to vital organs.Itcan also regulate HPA axis to promote fetal maturity.consequently,detectingthe level of cortisol and PG can guide the prevention of disease and providethe evidence of improving prognosis.Methods: Fifty-five neonates were selected from neonatology in ThePeople's Hospital of Xingtai who were divided to two groups according togestational age:full term infant group and premature group. There are15informer37.6±0.50in average gestational age and3000g±430.43g in averageweight, containing8boys and7girls. The premature group is divided into twogroups according to the etiology of birth:idiopathic preterm andpregnancy-induced hypertension preterm. In idiopathic preterm, the averagegestational age of twenty newborns are33.58±1.28, and their average weightis1990.59±408.68g, containing13boys and7girls. In Pregnancy-inducedhypertension preterm group, the average gestational age of twenty newbornsare33.83±3.10, and their average weight is1794.41±414.80g, containing12boys and8girls. All newborns in every group have no statistics differences ingestational age,weight and sex(P>0.05). And all mothers conform to thesecriterions: at the right age of pregnant,have no adverse habits,not use ofantibiotics,have no infection of prenatal,have no premature rupture ofmembranes(PROM),not use drugs to promote lung maturity.All neonateswithout intrauterine distress,asphyxia,Apgar score is normal.All newborns were collected blood of peripheral vein within30mins, andthen obtained serum by centrifuge. The levels of serum cortisol,cox-2and PG were ditected by enzyme-linked immunosorbent assay (ELISA).Combinedwith comparative analysis of relevant clinical data, a statistical treatment wasconducted.Results:1The change of serum cortisol levels of newborns in three groupsSerum cortisol level of full term infant group is higher than idiopathicpreterm group, there is a statistically difference (P＜0.05);Serum cortisol levelof full term infant group and idiopathic preterm group are significantly lowerthan Pregnancy-induced hypertension preterm group,there is an obviousstatistically difference (P＜0.05).2The change of serum cox-2levels of newborns in three groupsSerum cox-2level of full term infant group is higher than idiopathicpreterm group, there is a statistically difference (P＜0.05);Serum cox-2levelof full term infant group and idiopathic preterm group are significantly lowerthan Pregnancy-induced hypertension preterm group, there is an obviousstatistically difference (P＜0.05).3The change of serum PG levels of newborns in three groupsSerum PG level of full term infant group is higher than idiopathic pretermgroup, there is a statistically difference (P＜0.05);Serum PG level of full terminfant group and idiopathic preterm group are significantly lower thanPregnancy-induced hypertension syndrome preterm group,there is an obviousstatistically difference (P＜0.05).4The correlation analysis4.1The correlation analysis of serum cortisol and cox-2In full term infant group, serum cortisol and cox-2has correlation, there isa statistically difference(r=0.895,P<0.01).In idiopathic preterm group, serumcortisol and cox-2has no correlation, there is no statistically difference(r=-0.349,P>0.05).In Pregnancy-induced hypertension preterm group,serum cortisol and cox-2has correlation, there is a statistically difference(r=0.876,P<0.01).4.2The correlation analysis of serum cox-2and PG In full term infant group, serum cox-2and PG has correlation, there is astatistically difference(r=0.818,P<0.01). In idiopathic preterm group, serumcox-2and PG has no correlation, there is no statistically difference(r=-0.354,P>0.05).In Pregnancy-induced hypertension preterm group, serum cox-2andPG has correlation, there ia a statistically difference(r=0.770,P<0.01).4.3The correlation analysis of serum cortisol and PGIn full term infant group, serum cortisol and PG has correlation, there is astatistically difference(r=0.761,P<0.01).In idiopathic preterm group, serumcortisol and PG has no correlation, there is no statistically difference(r=-0.139,P>0.05).In Pregnancy-induced hypertension preterm group,serum cortisol and PG has correlation, there is a statistically difference(r=0.863,P<0.01).Conclusion:1The level of serum cortisol full term infant group is higher than idiopathicpreterm group, the change of it suggests that the ability of secretion of cortisolof fetus strengthened as gestational age increased,which indicates that it canreflect the function of fetal adrenal gland.2The level of serum cortisol of full term infant group is lower thanpregnancy-induced hypertension preterm group, the change of it suggests thatadrenal gland has a good regulation function of preterm infant. Therefore, thefetus at the state of stress response in pregnancy induced hypertensionsyndrome will increase the secrete of cortisol.3In full term infant group serum cortisol,cox-2and PG is in positivecorrelation,which indicates that the endocrine activity of fetal take part in theprocess of normal delivery.With the increase of gestational age,the secretion ofcortisol of fetal adrenal gradually increased. When it achieves a point, as aupper factor of prostate,it can increase the level of PG by induce theexpression of cox-2.The interaction of the three factors play an important rolein remaining pregnancy and starting delivery.4In Pregnancy-induced hypertension preterm group,the level of cortisol,cox-2and PG rises at the same time,which in positive correlation. It's indicate that more cortisol were secreted at the state of stress response,and then launchdelivery by cascade reaction.5The level of serum cortisol is not increased in idiopathic preterm groupthan full term infant group;In idiopathic preterm group, serum cortisol,cox-2and PG are in no Correlation.So it can be indicate that cortisol and relatedfactors take no participate in idiopathic preterm.6It is helpful for evaluation function of neonatal adrenal gland bymonitoring the level of cortisol of neonates.7Studying the regulation mechanism of cortisol,cox-2and PG by thetechnology in molecular biology, finding out the trigger point will provide anew way in preventing Pregnancy-induced hypertension preterm birth.