Kinetics of SRY gene appearance in maternal serum: detection by real time PCR in early pregnancy after assisted reproductive technique

BACKGROUND: Fetal DNA circulating in maternal serum offers a possibility for non-invasive prenatal diagnosis but its kinetics during very early pregnancy is still unclear. In order to clarify this point, the studies on the kinetics of fetal DNA appearance in maternal serum were conducted on patients undergoing assisted reproduction. METHODS: Using a quantitative real time PCR assay, the presence of SRY gene sequences was evaluated in the serum of patients at the onset of pregnancy. RESULTS: Twenty-seven patients were originally studied but first trimester abortion occurred in five cases. Among the 22 ongoing pregnancies, ten were found to bear at least one male fetus and all sera from these women gave positive results for SRY gene detection. The SRY gene was found to be detectable as soon as day 18 after embryo transfer in one case and it had been found in the other nine patients by day 37. CONCLUSIONS: Fetal DNA is found in maternal serum even before the fetal circulation is established, which is highly suggestive that it is released, at least in part, from the trophoblast. Detection of fetal DNA in maternal serum very early in pregnancy may have clinical implications such as with the management of pregnant women carrying a fetus at risk for congenital adrenal hyperplasia.     

用荧光原位杂交从母血中检测胎儿细胞

目的 从母血中分离胎儿细胞并确定其来自胎儿。方法 从孕早、中期各２０名、分娩后１５名母血中富集并分离有核细胞。用Ｙ特异性探针（ＰＹ３．４）行荧光原位杂交,从中识别胎儿细胞。结果 孕早、中期孕妇各怀１５名男胎。阳性细胞比例是１：６５２８．０及１：２７３．８。与同期１０名女胎阳性细胞相比,差别有高度显著性。分娩１周内的３名,阳必民孕中期的差别没有显著性。分娩３个月后的阳性率与比,差别有高度显著性。分娩     

甲基化荧光PCR定量检测母体循环中不同妊娠状态下胎儿maspin基因

目的依据孕妇血浆中存在游离胎儿DNA的理论,从孕妇外周血浆中分离出胎儿DNA并加以鉴定,预防X连锁遗传病患儿的出生。方法从孕早期、中期及晚期共80名孕妇外周血浆中分离胎儿DNA,采用实时荧光定量PCR（real- time fluorescence quantitative polymerase chain- reaction, FQ- PCR）方法对不同妊娠状态下孕妇外周血中游离的胎儿DNA（fDNA）进行定量分析,初步探讨游离fDNA在不同妊娠状态下的浓度变化,为尽早应用于临床提供科学依据。结果早孕组28例血浆标本中有25例检测到U—MASPIN基因,其平均浓度为57．82拷贝数／ml;中孕组20例血浆标本中均检测到U—maspin基因,其平均浓度为153．08拷贝数／ml;晚孕组32例血浆标本中均检测到U—maspin基因,其平均浓度为219．34拷贝数／ml,组间两两比较,差异有极显著意义（P〈0．01）。结论用实时荧光定量PCR的方法最早在孕72天的孕妇外周血浆中就可以检测到胎儿U－maspin基因,随孕周的增加,母血中胎儿DNA的量也在逐渐增加。实时荧光定量PCR技术在进行无创伤性产前性别诊断中有重要的价值。     

Correlation of maternal plasma total cell-free DNA and fetal DNA levels with short term outcome of first-trimester vaginal bleeding

BACKGROUND: The current methods using sonographic parameters and/or maternal serum beta-HCG levels to predict spontaneous abortion are not satisfactory. The aim of this study was to determine whether maternal plasma fetal DNA and total DNA levels could be used to predict spontaneous abortion. METHODS: We prospectively studied pregnant women who presented with vaginal bleeding in the first trimester of pregnancy, and those who had no vaginal bleeding (controls). DYS14 and the beta-globin gene were used to measure the maternal plasma levels of fetal and total DNA, respectively, by real-time PCR. RESULTS: A total of 1114 women were studied. Both maternal plasma fetal and total DNA concentrations increased with gestation from 6 to 11.6 weeks in the controls. The multiple of medians (MoMs) of fetal and total DNA concentration in those who miscarried were significantly greater (P < 0.001) than in the normal controls by about 5- and 4-fold respectively. Using a cut-off value of 1.6 MoMs for total DNA to predict spontaneous abortion, the sensitivity was 98.2% and false positive rate was 4.7%. However, using a cut-off value of 1.8 MoMs for fetal DNA, the corresponding figures were 97% and 44.3%, respectively. CONCLUSIONS: Both maternal plasma fetal and total DNA concentrations increased throughout the first trimester. Significantly high levels of fetal and total DNA were found in those who miscarried.     

An in-vivo study on placental transfer of naproxen in early human pregnancy

BACKGROUND: Naproxen is one of the most common non-steroidal anti-inflammatory drugs used by women of reproductive age. Naproxen is known to be teratogenic in animals. The aim of this study was to investigate the placental transfer of naproxen in the first trimester of human pregnancy, and to determine the amount of the drug in different embryonic compartments. METHODS: Twenty-eight patients who requested surgical termination of pregnancy in the first trimester were given two oral 500 mg doses of naproxen before the surgical procedure. Four biological samples, maternal venous blood, coelomic fluid, amniotic fluid and fetal tissue, were collected from each patient for drug analyses by high performance liquid chromatography. RESULTS: Naproxen was detected in all samples. The mean (+/- SD) concentrations were 69.5 +/- 12.2 microg/ml, 6.4 +/- 2.4 microg/g, 1.85 +/- 1.03 microg/ml and 0.14 +/- 0.11 microg/ml in maternal serum, fetal tissue, coelomic fluid and amniotic fluid respectively. The mean amniotic fluid/maternal drug ratio and fetal/maternal drug ratio were 0.002 (range 0.0005-0.0064) and 0.092 (range 0.022-0.155) respectively. There was a positive correlation between the fetal drug concentration (r = 0.59, P = 0.001), amniotic fluid drug concentration (r = 0.47, P = 0.013), amniotic fluid/maternal ratio (r = 0.536, P = 0.003) and fetal/maternal ratio (r = 0.72, P < 0.001) with advancing gestational age. CONCLUSIONS: Although naproxen can cross the placenta readily in the first trimester of human pregnancy, only a small amount was present in fetal tissues. Since there is no information on whether this small amount of naproxen would be teratogenic or not, women of reproductive age who are taking naproxen regularly should be warned of the possible fetal side-effects.     

Prenatal maternal blood screening for the detection of fetal chromosomal abnormalities: clinical importance of the rate of false positives

Maternal serum screening to identify fetal aneuploidies is now routinely offered during the second trimester of pregnancy in developed countries. The purpose of this prospective study was to assess the value of maternal serum screening between 15 and 20 weeks of gestation to detect fetal aneuploidies and to determine the false positive rate (FPR). Blood samples were collected from 1,062 pregnant women between 15 and 20 weeks of gestation. Samples were assayed for alpha-fetoprotein (AFP), free beta human chorionic gonadotropin (beta-hCG) and unconjugated estriol (uE3). Medians were established at each week from 200 normal, singleton pregnancies. Second trimester risk was calculated using the maternal age and different combinations of AFP, beta-hCG and uE3. Screening results calculated by likelihood ratio to be equal to or greater than 1:270 were considered positive. If the gestational age was confirmed by ultrasonography, genetic counselling and amniocentesis were offered. Ten fetal chromosomal abnormalities were detected with maternal serum screening. Sample's size does not allow a correct detection rate estimation, but false positive rate (FPR) was found to be 6.5%. This FPR has a clinical application. At a cut-off of 1:270, second trimester screening best results were obtained using a combination of all three biochemical markers. These results confirm the efficacy of maternal serum screening for fetal chromosomal abnormalities with a low FPR. The measurement of AFP, beta-hCG and uE3 is an effective prenatal screening test.     

Intrauterine aspiration in man in the early fetal period]

A total of 220 futuses obtained as a result of spontaneous and artificial abortions, 9-28 weeks of pregnancy, were investigated. The studies showed that intrauterine aspiration could be performed already beginning with the 11th-12th week of pregnancy. Intrauterine aspiration was determined on the basis of microscopical detection in the bronchi and in alveolar ducts of particles of the amniotic fluid (amnional epithelium and maternal leucocytes from the 11th-12th week, erythrocytes--from the 13th-14th week, horny scales--from the 15th-16th week, meconium--from the 23rd-24th week) and dilatation of the bronchoalveolar lumens. The fetal membranes in inflammation (chorioamnionitis) served as a sourse of aspitating leucocytes. Intrauterine aspiration most often took place in case of harmful effects upon the fetus. The cells of the amnional epithelium and epidermis, being aspirated, produced no harmful effect upon the fetus; the meconium was aspirated in the last hours of the abortion and had no time to produce morphologically identified reaction; aspiration of maternal leucocytes, not infrequently in combination with infection of the lungs, caused a proliferative inflummatory reaction in the fetus in the form of an enlarged number of cells in the stroma of the lungs, rounding of their nuclei, increased number of segmento-nuclear leucocytes and the appearance of round-celled peribronchial infiltrations. A proliferative inflammatory reaction was noted in fetuses beginning with the 13th-14th week of the intrauterine development.     

Second-trimester maternal serum alpha-fetoprotein levels and the risk of subsequent fetal death.

BACKGROUND. The finding of an elevated level of maternal serum alpha-fetoprotein during the second trimester of pregnancy may indicate that the fetus has died or is about to die. It is uncertain, however, whether the finding is associated with an increased risk of fetal death later in gestation independent of known causes of elevation, such as the presence of neural-tube defects or multiple gestation. METHODS. To address this question, we performed a case-control study of 612 women whose pregnancies ended in fetal death and 2501 women who gave birth to live infants, using reports from California vital statistics for 1987. All the women had signleton pregnancies and alpha-fetoprotein screening in the second trimester. RESULTS. Women with elevated levels of serum alpha-fetoprotein in the second trimester of pregnancy had an increased risk of fetal death, and the risk was increased until term. Women with the highest levels of serum alpha-fetoprotein--greater than or equal to 3.0 times the median value--had a very high risk of fetal death (odds ratio, 10.4; 95 percent confidence interval, 4.9 to 22.0) as compared with women who had normal levels of alpha-fetoprotein. Maternal serum alpha-fetoprotein levels that were 2.0 to 2.9 times the median were also associated with an elevated risk of fetal death (odds ratio, 2.4; 95 percent confidence interval, 1.7 to 3.4). Elevated levels of alpha-fetoprotein were especially likely to be associated with fetal death in cases in which maternal hypertension or placental infarction was also present. CONCLUSIONs. An unexplained elevated level of maternal serum alpha-fetoprotein in the second trimester of pregnancy is associated with an increased risk of subsequent fetal death, up to four to five months after alpha-fetoprotein screening.     

用实时荧光定量PCR方法检测母血中的胎儿SRY基因

目的　从孕妇外周血浆中分离出胎儿DNA ,并加以鉴定 ,预防X连锁遗传病患儿的出生。方法　从孕早期、中期共 3 0 0名孕妇外周血浆中分离胎儿DNA ,用实时荧光定量聚合酶链反应 (fluorescencequantitativepolymerasechainreaction ,FQ PCR)的方法检测其中的Y性别决定区 (sex determiningregionY ,SRY)基因。结果　孕早期怀男胎的孕妇 82名 ,70名SRY基因阳性 ,其平均浓度为 ( 5 8.82± 2 0 .90 )拷贝 /ml,中位数为 5 8.5 0拷贝 /ml。孕中期怀男胎的孕妇 90名 ,SRY基因均为阳性 ,平均为 ( 15 2 .0 8± 62 61)拷贝 /ml,中位数为 14 9.3 5拷贝 /ml。怀女胎的孕妇均为阴性。结论　用实时荧光定量PCR的方法最早在孕42天的孕妇外周血浆中就可以检测到胎儿SRY基因 ,随孕周的增加 ,母血中胎儿DNA的量也在逐渐增加。实时荧光定量PCR技术在进行无创伤性产前性别诊断中有重要的价值。     

Amanita poisoning during the second trimester of pregnancy

Amanita phalloides-type mushroom poisoning is well recognized as causing acute liver injury and often death. Less is known, however, of whether maternal Amanita poisoning is associated with fetal damage or not. In August 1991 four members of a family were hospitalized with food intoxication caused by Amanita phalloides and Amanita verna. One of them died from hepatic and renal failure. The survivors included a 26-year-old woman in the 23rd week of pregnancy. Her clinical symptoms and blood chemistry data (lowest prothrombin activity 23%) indicated intoxication of medium severity. The management consisted of i.v. hydration, forced diuresis, and administration of silibinin, high-dose penicillin, thioctic acid, hydrocortisone, vitamin K, and fresh frozen plasma. Sonographic and obstetric controls failed to show any fetal abnormalities in the acute phase of poisoning. In the 38th week of pregnancy she gave birth to a healthy baby, who has subsequently undergone an undisturbed development. This observation indicated that severe fetal damage did not occur in maternal Amanita poisoning in the second trimester of pregnancy. Thus, at least from the second trimester on, maternal Amanita poisoning is not necessarily an indication for induced abortion.Abbreviations ALAT alanine aminotransferase - BPD biparietal diameter - FOD fronto-occipital diameter - US ultrasonography Correspondence to: I. Nagy     

母体循环中胎儿游离DNA的定量分析

目的依据孕妇血浆中存在游离胎儿DNA的理论，从孕妇外周血浆中分离出胎儿DNA并加以鉴定，预防x连锁遗传病患儿的出生。方法从孕早期、中期共78名孕妇外周血浆中分离胎儿DNA，用实时荧光定量聚合酶链反应（fluorescence quantitative polymerase chain reaction，FQ—PCR）的方法检测其中的Y性别决定区（sex—determining region Y，SRY）基因。结果孕早期怀男胎的孕妇28名，25名SRY基因阳性，其平均浓度为（58．82±25．22）拷贝／ml；孕中期怀男胎的孕妇20名，SRY基因均为阳性，平均为（152．08±62．61）拷贝／ml；怀女胎的孕妇均为阴性。结论用实时荧光定量PCR的方法最早在孕62天的孕妇外周血浆中就可以检测到胎儿SRY基因，随孕周的增加，母血中胎儿DNA的量也在逐渐增加。实时荧光定量PCR技术在进行无创伤性产前性别诊断中有重要的价值。     

Congenital cytomegalovirus infection following first trimester maternal infection: symptoms at birth and outcome.

BACKGROUND: The relationship between gestational age at time of maternal cytomegalovirus (CMV) infection and outcome of fetal infection is not well defined because the timing of maternal infection is usually not known. OBJECTIVE: To determine whether congenital cytomegalovirus (CMV) infection following primary maternal infection during the first trimester of pregnancy is more likely to lead to central nervous system (CNS) sequelae than fetal infection due to maternal infection later in pregnancy. STUDY DESIGN: Using serum collected during pregnancy from mothers of newborns with congenital CMV infection, maternal infection was categorized as first trimester (<13 weeks) or later based on dates and results of IgG and IgM assays for CMV antibody. Outcome of congenital CMV infection was assessed by longitudinal fotlow-up of the infected cohort. RESULTS: Sensorineural hearing loss was found in 8/34 (24%) of children in the first trimester group, compared with 1/40 (2.5%) in the later infection group (P=0.01, relative risk, 9.6). Considering any CNS sequela (hearing loss, mental retardation, cerebral palsy, seizures, chorioretinitis) 11/34 (32%) first trimester cases were affected compared with 6/40 (15%) in the later infection group (P=0.07, relative risk 2.2). None of the later group had more than one sequela, compared with 4 (12%) of the first trimester group (P=0.04). CONCLUSIONS: Children with congenital CMV infection following first trimester maternal infection are more likely to have CNS sequelae, especially sensorineural hearing loss, than are those whose mothers were infected later in pregnancy. However, some degree of CNS impairment can follow even late gestational infection.     

Ontogeny of T lymphocyte differentiation in the human fetus: acquisition of phenotype and functions

Phenotype and functions of cells of the T lymphocyte lineage from fetal liver, thymus, spleen and bone marrow were investigated at various ages. T lymphocyte differentiation was shown to be initiated in the thymus after the 7th week of gestation. In this organ, a large number of cells with a phenotype comparable to that of children thymocytes and with a high proliferative response to phytomitogens was observed at the 14th week. The fetal liver and bone marrow never contained many T-cells and the liver was shown to be virtually devoid of any of these cells before the 13th week. Fetal spleen contained appreciable amounts of T-cells after the 13th week. Helper and suppressor activities of fetal thymocytes and splenocytes were acquired between the 12th and the 16th week, but they were never as complete nor as potent as those of adult lymphocytes. HLA antigens were detected in very low amount in lymphocytes from the various organs at the beginning of the second trimester and their expression was significantly enhanced by in vitro incubation with alpha-interferon (alpha-IFN), a procedure that permits easier HLA typing of fetal cells.     

早孕期母血循环中胎儿细胞的检测

自行设计引物并建立早孕妇女外周血中胎儿细胞检测的巢式ＰＣＲ方法、计算机辅助设计的两对引物位于Ｙ染色体ＺＰＹ基因保守区内,扩增产物分别是３５４ｂｐ和３０７ｂｐ,该引物具有高度的特异性和敏感性。应用该引物对３１例６１４周的早孕妇女连续采血基因扩增,１９例妊娠男性胎儿妇女外周血中孕６周即有胎儿细胞检出１／１９（５３％）,ＺＰＹ基因检出率随孕周增加而增高,而到孕１２周则达到１８／１９（９４７％）,总有效率可达９６８％。提示该方法检测胎儿细胞ＤＮＡ是可行的、且胎儿细胞最早进入母血循环的时间存在明显的个体差异,利用母血中胎儿细胞进行产前诊断的最佳采血时间以孕１２周以后为宜,并应注意假阳性结果的判断。     

The increased lysis of fetal cells in the mother after pregnancies complicated by pre-eclampsia or HELLP syndrome is not the result of a specific anti-fetal cytotoxicity of the mother

PROBLEM: In pregnancies complicated by pre-eclampsia or hemolytisis elevated liver enzymes, low platelets (HELLP) syndrome, an increase of fetal DNA in the maternal serum indicates an increased lysis of fetal cells. Whether this cytolysis is the cause or the result of an increased specific cytotoxicity against the fetal cells is not yet known. METHODS: Ten mothers after healthy pregnancy, eight mothers after pregnancy complicated by prematurity (GA < 37 weeks), and eight mothers with pregnancies complicated by pre-eclampsia or HELLP syndrome and their male children were enrolled in the study. Fetally derived DNA in the maternal serum and the specific anti-fetal cytotoxicity of the maternal lymphocytes were measured. RESULTS: Detection of fetal DNA in maternal serum was significantly associated with pre-eclampsia/HELLP syndrome but not with anti-fetal cytotoxicity of the maternal lymphocytes. CONCLUSION: The cytolysis of fetal cells in mothers after pregnancies complicated by pre-eclampsia/HELLP syndrome is neither the reason for nor the result of an increased specific anti-fetal cytotoxicity.     

Elevated second trimester maternal serum beta-HCG concentrations and subsequent adverse pregnancy outcome.

Previous studies have found an association between elevated second trimester maternal serum alpha-fetoprotein (MS-AFP), in the absence of fetal anomalies, and adverse pregnancy outcome. We studied the association between elevated second trimester maternal serum beta-HCG, now also routinely measured by prenatal screening programs, and adverse pregnancy outcome by reviewing retrospectively the pregnancy outcomes among women with markedly elevated midtrimester beta-HCG in our prenatal screening program. Seven (0.23%) of 3,000 consecutively screened women had a serum beta-HCG above 5 MOM. Four (57%) of these 7 women had an adverse pregnancy outcome including severe preeclampsia (n = 2), abruptio placentae (n = 1), or preterm labor (n = 1). A concurrently elevated MS-AFP was found in only one of these 4 patients. Elevated mid-trimester maternal serum beta-HCG may be an independent risk factor for subsequent adverse pregnancy outcomes.     

Clinical applications of fetal sex determination in maternal blood in a preimplantation genetic diagnosis centre

BACKGROUND: Couples with a risk of transmitting X-linked diseases who are included in a preimplantation genetic diagnosis (PGD) programme need early and rapid fetal sex determination in two situations. The first situation is for the control of embryo sexing after PGD and the second situation is for those couples having a spontaneous pregnancy before the start of their PGD cycle. Among invasive techniques, chorionic villus sampling is the earliest procedure for fetal sex determination and molecular analysis of X-linked genetic disorders during the first trimester but it is associated with a risk of fetal loss. Non-invasive procedures such as ultrasound examination allow reliable fetal sex determination only during the second trimester. Reliable fetal sex determination can now be realised by using SRY gene amplification in maternal blood. METHODS AND RESULTS: We report the use of fetal sex determination from maternal serum as a diagnostic tool for the control of embryo sexing (two cases) and to manage spontaneous pregnancies in couples included in a PGD programme for X-linked diseases (five cases). Fetal sex determination using SRY gene amplification in maternal serum were in complete concordance with fetal sex observed by cytogenetic analysis or ultrasound examination and at birth. This novel strategy allowed the PGD results to be controlled precociously and avoided the performance of invasive procedures in four cases of female fetus. CONCLUSIONS: This rapid fetal sex determination during the first trimester provides advantages to both clinicians and patients in a PGD centre.     

Alterations in polyamine levels in amniotic fluid, plasma and urine during normal pregnancy

Polyamines have a close relationship with rapid cell proliferation. We measured polyamine levels in amniotic fluid, maternal plasma and urine during normal pregnancy. Plasma putrescine, spermidine and spermine gradually increased in the third trimester and reached the highest concentration at the end of pregnancy. There was a significant correlation between the level of these polyamines and the level of plasma estradiol and progesterone. In urine, putrescine and spermine increased with the progress of gestation and reached the highest level during the 8th to 10th months of gestation. In amniotic fluid, putrescine and spermidine concentrations were significantly high in the first trimester and decreased in the other trimesters, whereas spermine showed no significant change. Polyamine concentrations in maternal plasma and urine appear to reflect not only fetal metabolic changes but also the metabolic changes of the pregnant women, and to be influenced by several hormones which increase during pregnancy. Polyamines in amniotic fluid mainly reflect activated fetal metabolism and may be useful as biochemical indicators of fetal growth.     

Feto-maternal transfusion after chorionic villus sampling: clinical implications

Feto-maternal transfusion following chorionic villus sampling (CVS) in the first trimester of pregnancy was evaluated by alpha-fetoprotein (AFP) level determination in maternal serum before and after sampling. Some fetal haemorrhage was suggested in 72% of 283 continuing pregnancies by a significant increase of maternal AFP level. Fetal bleeding appeared to stop a short time after CVS, and did not complicate detection of neural tube defects (NTDs) in the second trimester. The change in the maternal serum AFP level was correlated with the size of the chorionic tissue specimen, but no association was observed between fetal and neonatal outcome. The risk of maternal rhesus (Rh) iso-immunization must be taken into account, and anti-D immunoglobulin administrated after CVS. Maternal Rh immunization should be considered as a contraindication to CVS.     

Update on the prevention,diagnosis and management of cytomegalovirus infection during pregnancy

Human cytomegalovirus (CMV) is the leading cause of congenital infection, with morbidity and mortality at birth and sequelae. Each year approximately 1–7% (Rev Med Virol 2010; 20: 311) of pregnant women acquire a primary CMV infection. Of these, about 30–40% transmit infection to their fetuses. The risk of serious fetal injury is greatest when maternal infection develops in the first trimester or early in the second trimester. Between 10 and 15% of congenitally infected infants are acutely symptomatic at birth and most of the survivors have serious long-term complications. Until a few years ago, laboratory testing was not possible to precisely define the maternal immune status, the recent development of advanced serological tests (IgG avidity test, IgM immunoblot and neutralizing antibody testing) allow us to identify, among pregnant women with suspected CMV, those with primary infection who are therefore at high risk of transmitting CMV to the fetus. This is done with the use of a screening test. As most maternal infections are asymptomatic, the only way to disclose primary infection is to implement specific serological testing as early in pregnancy as possible (before week 12–16 of gestation). Given the high risk of mother–fetus transmission and fetal damage, prenatal diagnosis is recommended to women with primary CMV infection contracted in the first half of pregnancy and in case of fetal abnormalities suggestive of infection. The correct interpretation of serological and virological tests followed by appropriate counselling by an expert physician is an effective tool to reduce the number of unnecessary pregnancy terminations by over 70% (Am J Obstet Gynecol 2007; 196: 221.e1).