Intrauterine infection,immune system and premature birth

Preterm birth accounts for nearly one million deaths among children under five years of age, and although its etiopathogenesis is not fully elucidated, ascending intrauterine infection and fetal inflammatory response seem to be the main triggers. The intense inflammatory response mediated by IL-1β, TNF-α, PAF, IFN-γ and IL-6, PGE₂ and MMP-1 and MMP-9 causes fetal membrane damage and rupture, increased uterine contractions and biochemical and structural changes in the cervix. Furthermore, preterm neonates have deficient innate and adaptive immune responses characterized by reduced levels of IgG, opsonization and phagocytosis, as well as increased activation of Th1 cells in relation to Th2 cells. Therefore, this triad is favors the occurrence of neonatal complications, such as respiratory distress syndrome, necrotizing enterocolitis, retinopathy of prematurity and bronchopulmonary dysplasia. Due to serious maternal and child health complications of intrauterine infection, several studies have tried to identify biomarkers for the early diagnosis of this entity. This literature review aims to discuss the main scientific findings regarding the association between ascending intrauterine infection, immune system and preterm birth.     

Treatment of threatened premature labor due to subclinical intrauterine infection

Recent reports reveal that some threatened premature labors (tpl) are caused by intrauterine infections. And the prognosis of tpl due to intrauterine infections are worse than tpl due to other factors because of lower sensitivity to the beta-stimulants. So we examined the relationship between tpl and intrauterine infections retrospectively by obtaining intracervical cultures of inpatients who suffered from tpl, and prospectively by getting intracervical cultures from healthy pregnant women at a gestational age around 20 weeks, and divided them into two groups--the infectious group and non-infectious group--and studied the tpl rate. The patients who had positive bacterial cervical cultures were again divided into two groups. One group had antibiotics administered orally and the other had none. The tpl rate was observed. The results are: 1. Thirty two point six percent of tpl inpatients were found to be infected intracervically. No statistical significance was noted in the microbodies detected. 2. Three cases of premature labor at less than 35 gestational weeks were observed in the infected group. 3. The majority of infected group showed high CRP levels, and the study of Preterm Labor Score (PLS) showed that most cases over 4 points of PLS were infected. 4. In a prospective study, 18 of 100 healthy pregnant women showed positive intracervical bacterial cultures. The tpl rates were 44.4% in all of the infected group. Twenty two point two percent of tpl rate in the antibiotic administration group and 66.7% in the non-administration group (p less than 0.01). And the non-infected tpl rate was 11.0% (p less than 0.01), or only 9 cases out of 82.(ABSTRACT TRUNCATED AT 250 WORDS)     

Frequency of spontaneous abortion and premature birth after acute mumps infection in pregnancy

OBJECTIVE: Since mumps infection is endemic, the occurrence of acute mumps infection during pregnancy is rare. As a result, data on the possible negative consequences of acute mumps infection on pregnancy outcome are limited. PATIENTS AND METHODS: The clinical diagnosis of acute mumps infection was serologically confirmed in 79 pregnant women between January 1985 and December 2002. Data on pregnancy outcome were obtained from the gynaecologist or obstetrician. Cord blood from 26 of the 57 live-born infants was investigated for mumps-specific IgM and IgG antibodies by enzyme-linked immunoassay. RESULTS: Sixty-two patients were prospectively followed up with respect to pregnancy outcome. Two of the 62 pregnancies were electively terminated. The overall rate of fetal loss was 6.6% (4/60). Only 2 cases of spontaneous abortion occurred during the first trimester. However, all 4 spontaneous abortions occurred in women who had contracted mumps infection during the first trimester. The time interval between mumps infection and fetal loss varied widely. The median gestational age at delivery was 40 weeks.Only 2 of the 57 live-born infants (3.5%) were delivered before completion of the 37th week of pregnancy. Mumps-specific IgM anti-bodies were not detected in any of the 26 cord blood samples tested. CONCLUSION: The lack of mumps-specific antibodies in the cord blood samples tested suggests that prenatal mumps infection did not occur. The frequency of premature birth and spontaneous abortion following mumps infection in pregnancy does not appear to be increased over normal levels.     

早产产前糖皮质激素的使用

早产是全球范围内围产期新生儿死亡率和发病率高的主要问题。早产孕妇产前接受糖皮质激素治疗后可以有效降低早产儿呼吸窘迫综合征、脑室内出血和坏死性小肠结肠炎等的发生率。但世界各国关于产前糖皮质激素的使用略有不同,文章就现有产前糖皮质激素使用的循证医学证据做一总结,以期指导临床实践。     

Role of amniocentesis for the diagnosis of subclinical intra-amniotic infection in preterm premature rupture of the membranes

The clinical role of amniocentesis in the management of pregnancies that are complicated by preterm premature rupture of the membranes remains unclear. The indiscriminant use of expectant management, corticosteroids, and empiric antibiotic therapy without knowledge of the presence or absence of intra-amniotic infection poses underappreciated risks to the fetus. This clinical opinion presents the argument that amniocentesis should be an integral part of the management of patients with preterm premature rupture of the membranes. The technical aspects of amniocentesis, the associations between subclinical infection and neonatal morbidity, and the limitations of current interventions are reviewed, and suggestions for future studies that are sorely needed are offered.     

生殖道感染与早产

生殖道感染是早产的重要因素,两者的关系随着孕周而改变。除阴道外,宫颈和胎盘都有其独立的菌群定植,但宫颈和胎盘的微生物群与早产之间的关系仍需进一步研究。目前对于抗生素的使用仍未有统一意见。     

The relationship between bacterial vaginosis and preterm birth. A review

Bacterial vaginosis is currently the most prevalent form of vaginal infection of reproductive age women. The etiology of bacterial vaginosis has not yet been defined. However, clear criteria for diagnosis and treatment have been established in the absence as well as in presence of pregnancy. Recent data show an association between bacterial vaginosis and preterm labor and delivery. This review outlines the role of bacterial vaginosis in preterm birth and other pregnancy complications.     

早产预测的研究现状

早产的预测手段包括病史、宫颈长度和阴道分泌物中生物标志物检测等。建议针对早产高危人群进行宫颈长度的筛查和监测。生物标记物对无症状孕妇的早产预测价值尚不能肯定,但对于先兆早产孕妇有一定的预测价值,可以联合宫颈长度的超声检测提高预测的准确性。今后仍然需要进一步研究预测方法的有效性。     

Preterm birth, premature rupture of membranes, and cervical incompetence.

Preterm birth, due to shortened gestation with birth prior to 37 completed weeks gestation, accounts for up to 75% of perinatal morbidity and mortality in the United States. Much basic and clinical research is focused on understanding the epidemiology, pathobiology, and possible means to treat or prevent preterm labor, premature rupture of membranes, and cervical factors leading to preterm birth. Recent key areas of progress in these problems are selectively reviewed, emphasizing aspects that are considered most important for further progress.     

Congenital varicella-zoster virus infection after maternal subclinical infection: clinical and neuropathological findings.

OBJECTIVE: It is known that varicella-zoster virus (VZV) can cause asymptomatic infections, but it has not been described that congenital infection can be caused by maternal subclinical infection. The purpose of this study is to evaluate clinical and neuropathologic findings of infants with neonatal seizures and cerebrospinal fluid (CSF) VZV antibodies, but no maternal clinical VZV infection during the pregnancy. STUDY DESIGN: Screening of 201 neonates were studied for congenital viral infections, because of neurologic problems of unknown origin. Antibodies to 16 different microbes were investigated from the CSF and the serum of the neonates, as well as from the first trimester and postpartum serum of their mothers. Clinical symptoms and signs as well as neuropathology of those infants with antibodies to VZV in CSF were evaluated in this study. RESULTS: Four neonates with antibodies to VZV in CSF were identified and CSF findings were reported earlier. Their mothers had laboratory evidence of infection, based on a significant rise in serum VZV antibody level during pregnancy in three mothers, and a constantly high antibody level to VZV in one mother. All four children had seizures and abnormalities in muscular tone during the neonatal period, but no typical manifestations of a congenital VZV infection. One child died at the age of 4 months. At autopsy, neuropathologic examination showed foci of astrocytic hyperplasia and hypertrophy but no specific signs of viral infection. CONCLUSION: Maternal subclinical VZV infection can cause congenital infection with neurologic symptoms and signs in the child.     

降钙素原、新蝶呤与亚临床感染胎膜早破的相关性研究

目的:探讨降钙素原(PCT)和新蝶呤(Npt)在足月胎膜早破孕妇血清及脐血血清中的水平与亚临床感染的关系。方法:选取剖宫产分娩的足月胎膜早破孕妇20例作为实验组,同期因社会因素剖宫产分娩的正常足月孕妇20例作为对照组;采用酶联免疫法(ELISA)测定孕妇血清与脐血血清中PCT、Npt的水平。取胎膜组织行组织病理学检查,根据结果分为绒毛膜羊膜炎组和非绒毛膜羊膜炎组。结果:(1)实验组中孕妇血清PCT(59.787±18.781)和Npt(14.874±4.462)水平均较对照组高(38.630±16.119,10.388±1.704)(P<0.05);实验组中脐血血清PCT(69.196±19.719)和Npt(16.615±4.220)水平均较对照组高(46.926±15.963,12.018±1.849)(P<0.05);实验组孕妇血清中PCT和Npt的水平均与脐血血清中两者的水平分别呈正相关(P<0.05);实验组孕妇血清PCT和Npt的水平没有相关性(P>0.05);(2)胎膜组织病理学检查发现绒毛膜羊膜炎孕妇共19例(实验组占14例,而对照组占5例);绒毛膜羊膜炎组孕妇血清中PCT(58.448±20.024)和Npt(15.040±4.510)水平均高于非绒毛膜羊膜炎组(40.848±17.041,10.403±1.713)(P<0.05)。结论:孕妇血清和脐血血清中PCT和Npt水平与亚临床感染足月胎膜早破有相关性;有望通过检测孕妇血清PCT和Npt水平间接的反应亚临床感染胎膜早破孕妇和宫内胎儿感染的严重程度。     

Present means to prevent premature birth

Although overall statistics do not show marked decrease in the percentage of infants with a birth weight under 2,500 g, therapeutical advances of the past few years would allow to conduct an action to prevent prematurity. Namely: beta-stimulating agents can control threatened premature delivery, provided the mothers-to-be, and this is essential, get alarmed without delay and seek prompt advice of their physician, screening and treatment of cervicovaginal infections during pregnancy can undoubtedly be efficient, provided the future mothers are regularly visited from the begining of their pregnancy. But such a prophylaxis necessarily requires, at the various stages of its practice, intelligent cooperation of the pregnant women themselves. Such a cooperation could perhaps be obtained through obstetrical psychoprophylactic interviews as a complement to antenatal consultations, the number of which is too small and the time spent on them too short within the organizational frame of community medicine.     

Haemophilus parainfluenzae sepsis in a very low birth weight premature infant: a case report and review of the literature.

Haemophilus parainfluenzae is an unusual cause of invasive bacterial disease and is particularly uncommon as a reported etiology of neonatal sepsis in current large published series. We describe a seriously ill, very low birth weight (VLBW) infant with documented early onset sepsis caused by H. parainfluenzae. We compare our case with those published previously and contrast the clinical presentation of infection in our patient to that of common bacterial pathogens causing neonatal sepsis. Our review suggests many common factors in the pathogenesis of early onset infection by H. parainfluenzae.     

Perspectives in the prevention of premature birth

Obstetric and neonatal interventions have improved the survival of preterm infants, but there has not been an equivalent reduction in long-term neurological disability. Thus, some effort must be invested in finding ways of preventing preterm birth. Numerous programmes have been promoted to address the matter of how the frequency of preterm birth could be prevented. Most interventions intended to prevent preterm labour do not have the desired effect, except for antibiotic treatment in cases of asymptomatic bacteriuria or bacterial vaginosis and progesterone administered prophylactically in high-risk women. Tocolytic drugs appear to delay delivery long enough for successful administration of corticosteroids in women in preterm labour, but without decreasing the risk of preterm birth. Some authors promote public health approaches that address all risk factors and affect the entire population of pregnant women, given that prevention programmes directed only at high-risk women have had little effect in preventing preterm births. However, the lack of progress in reducing the frequency of preterm births is also due to our limited understanding of the aetiology of preterm delivery. Although there is growing evidence that infection and neuroendocrine processes are involved, progress has remained slow. Recently, the hypothesis of a genetic predisposition to preterm delivery has been set up. Additional research exploring the pathophysiology of preterm labour is obviously needed, which will hopefully lead to the development of new therapeutic approaches.     

Prevention of premature birth by a transabdominal puncture procedure before the birth. Drainage of amniotic sac

Summary Amniotic fluid is a major factor of the intrauterine environment, and deviation from the normal volume is associated with an increased perinatal morbidity and mortality. Polyhydramnios occurs in 0.2 to 1.6 % of pregnancies. It may be due to a number of congenital anomalies, an abnormal karyotype, maternal diabetes, Rh-disease or intrauterine infections potentially requiring non-invasive or invasive measures. However, the most common indication for prenatal intervention due to polyhydramnios is the Twin-Twin-Transfusion Syndrom (TTTS). Treatment of polyhydramnios may focus on correction of the causative lesion, or symptomatic relief through drainage of amniotic fluid. Maternal administration of cyclooxygenase inhibitors represents a further, non-invasive therapeutic option. Indomethacin, Sulindac, or Nimesulide reduce the fetal urine output thus decreasing amniotic fluid volume over time without the risks associated with invasive procedures. However, potentially serious ductal constriction as well as a delay in the onset of amniotic fluid reduction have limited its application. Percutaneous amniotic fluid drainage may provide immediate reduction of intrauterine pressure, but is associated with a complication rate of 1 to 1.5 %. The hemodynamic characteristics of monochorionic pregnancies complicated by TTTS have led to the development of endoscopic laser coagulation of placental vascular anastomoses as a definitive treatment. Treatment is only required in a small minoritiy of pregnancies with polyhydramnios. Mild cases can be managed expectatively. Intrauterine pressure increases with an excessive increase in amniotic fluid volume (AFI > 400 mm or MVP > 150 mm) leads to the elevation of intrauterine pressure. Complications such as preterm premature rupture of membranes and preterm labor may lead to premature delivery. The main goal of prenatal treatment of polyhydramnios is thus the improvement of fetal outcome through prolongation of gestation and/or the alleviation of maternal symptoms.      

Traditional birth attendants and birth outcomes in low-middle income countries: A review

Traditional birth attendants (TBAs) provided delivery care throughout the world prior to the development of organized systems of medical care. In 2016, an estimated 22% of pregnant women delivered with a TBA, mostly in rural or remote areas that lacked formal health services. Still active in many regions of LMICs, they provide care, including support and advice, to women during pregnancy and childbirth. Even though they generally have no formal training and are not recognized as medical practitioners, TBAs enjoy a high societal standing and many families seek them as health care providers. They are generally older women who have acquired their skills acting as apprentices of other TBAs or are self-taught.WHO and other international organizations have focused maternal mortality reduction efforts on the availability of skilled birth attendance, which excludes TBAs as providers of care. However, as countries move towards SBA, policy makers need to make the best use of TBAs while simultaneously planning for their replacement with skilled attendants. They often serve as a bridge between the community and the formal health system; once women are inside an institution, TBAs could potentially act as doulas, providing company and making women feel more comfortable in an unknown environment. In this paper, we will review who TBAs are, how many births they attend worldwide worldwide, where they provide delivery care, and finally, their relationships with the formal health care system and the communities they serve.     

Trichomonas vaginalis infection in a premature newborn.

Trichomonas vaginalis is a vaginal pathogen associated with an increased incidence of adverse outcomes of pregnancy. Data are limited regarding the effects of Trichomonas infections in the newborn. We report a symptomatic T. vaginalis infection in a 26-week premature infant and a review of the literature.     

早产与胎膜早破189例分析

本文分析了我院１９９１～１９９４年早产４５２例，其中ＰＲＯＭ１８９例。ＰＲＯＭ发生率为４１．８％，围产儿病死率为７４．６‰，胎儿宫内窘迫率为８．５％，新生儿窒息率为１２．６％．ＰＲＯＭ组产前感染率为５．８％，高于对照组（Ｐ＜０．００５）。６３．６％的感染发生在破膜２天之内。ＰＲＯＭ组产后子宫内膜炎发生率为３．７％，高于对照组（Ｐ＜０．０５）。ＰＲＯＭ的潜伏期在４８小时内者占６７．７％。ＰＲＯＭ组剖宫产率为２５．４％。ＰＲＯＭ的主要危险是早产和产前、产后感染。本文对早产和ＰＲＯＭ的相互关系及处理进行了讨论。