Amniocentesis In Pregnancies Research Articles

Amniocentesis in pregnancies at or beyond 24 weeks: an international multicenter study

BackgroundAmniocentesis for genetic diagnosis is most commonly done between 15 and 22 weeks of gestation, but can be performed at later gestational ages. The safety and genetic diagnostic accuracy of amniocentesis have been well-established through numerous large-scale, multicenter studies for procedures before 24 weeks, but comprehensive data on late amniocentesis remain sparse. ObjectivesTo evaluate the indications, diagnostic yield, safety, and maternal and fetal outcomes associated with amniocentesis performed at or beyond 24 weeks of gestation. Study DesignWe conducted an international, multicenter retrospective cohort study examining pregnant individuals who underwent amniocentesis for prenatal diagnostic testing at gestational ages between 24w0d and 36w6d. The study, spanning from 2011 to 2022, involved nine referral centers. We included singleton or twin pregnancies with documented outcomes, excluding cases where other invasive procedures were performed during pregnancy or if amniocentesis was conducted for obstetric indications. We analyzed indications for late amniocentesis, types of genetic tests performed, their results, and the diagnostic yield, along with pregnancy outcomes and post-procedure complications. ResultsOf the 752 pregnant individuals included in our study, late amniocentesis was primarily performed for the prenatal diagnosis of structural anomalies (91.6%), followed by suspected fetal infection (2.3%) and high-risk findings from cell-free DNA screening (1.9%). The median gestational age at the time of the procedure was 28w5d, and 98.3% of pregnant individuals received results of genetic testing before birth or pregnancy termination. The diagnostic yield was 22.9%, and a diagnosis was made 2.4 times more often for fetuses with anomalies in multiple organ systems (36.4%) compared to those with anomalies in a single organ system (15.3%). Additionally, the diagnostic yield varied depending on the specific organ system involved, with the highest yield for musculoskeletal anomalies (36.7%) and hydrops fetalis (36.4%) when a single organ system or entity was affected. The most prevalent genetic diagnoses were aneuploidies (46.8%), followed by copy number variants (26.3%) and monogenic disorders (22.2%). The median gestational age at delivery was 38w3d, with an average of 59 days between the procedure and delivery date. The overall complication rate within two weeks post-procedure was 1.2%. We found no significant difference in the rate of preterm delivery between pregnant individuals undergoing amniocentesis between 24-28 weeks and those between 28-32 weeks, reinforcing the procedure's safety across these gestational periods. ConclusionsLate amniocentesis, at or after 24 weeks gestation, especially for pregnancies complicated by multiple congenital anomalies, has a high diagnostic yield and a low complication rate, underscoring its clinical utility. It provides pregnant individuals and their providers with a comprehensive diagnostic evaluation and results before delivery, enabling informed counseling and optimized perinatal and neonatal care planning.

O44: Diagnostic yield of amniocentesis in pregnancies ≥24 weeks: An international multicenter study*

O44: Diagnostic yield of amniocentesis in pregnancies ≥24 weeks: An international multicenter study*

Comparing Non-invasive Prenatal Testing With Invasive Testing for the Detection of Trisomy 21.

Background Non-invasive prenatal test (NIPT) is an intermediate step between serum screening and invasive diagnostic testing. It involves analysis of the cell-free fetal DNA (cffDNA) present in the maternal blood sample for determining the likelihood of fetal aneuploidy. Owing to its high sensitivity and specificity, NIPT has quickly gained popularity across the globe since its introduction to clinical practice, making it an attractive alternative to the available screening and diagnostic tests in use.Amniocentesis is currently the gold standard test for obtaining fetal DNA and diagnosing fetal trisomy prenatally, but it is invasive and has procedure-related adverse effects.This study aims to compare NIPT and amniocentesis in pregnancies screened positive for fetal trisomy. Material and methods This is an analytic cross-sectional prospective study conducted in the Department of Obstetrics & Gynecology, Patna Medical College and Hospital, for two and half years from December 2018 to June 2021. A total of 34 pregnant women screened positive for trisomy 21, attending the antenatal care outpatient department, in their second trimester, with their written consent, were enrolled in the study. Results Out of 34 pregnant patients, three refused NIPT and directly opted for amniocentesis. A total of 31 pregnant women have undergone NIPT. A total of 28 cases were positive for trisomy 21 on both NIPT and amniocentesis. The sensitivity of NIPT was 100% with the confidence interval being 87.66% to 100.00%. The specificity of NIPT was 100% with the confidence interval being 29.24% to 100.00%. Conclusion The high performance and effectiveness of NIPT are undeniable. Thoughthe process by which this test has to be integrated into the clinical practice needs more study and should be determined with meticulous assessment.

PFM.32 Third trimester amniocentesis for the diagnosis of haemophilia A and B

Haemophilia A and B are bleeding disorders inherited in an X linked recessive manner. Female carriers of these conditions have a 50% chance of delivering an affected infant when pregnant...

The course and outcome of a pregnancy with a prematura preterm rupture of membranes dilema or liability

Preterm premature rupture of membranes (PPROM) is in obstetrics with incidence of 0,4% of , with risk for chorioamnionitis 35%, risk for premature deli very 19%, and sepsis risk of 1%. Primary risk for fetus is pulmonal hypoplasia due to oligohydramnios in 29%, RDS in 66 % of such pregnancies, sepsis in 19%, and contracture of extremities in 3%. Fetal death is more than 30% of cases. Patient came to regular pregnancy check up in 22th week of gestation. US examination revealed decreased fluid volume AFI 50, with regular morphology and fetal dynamic. She was admitted to hospital. She was given cortico-steroids and antibiotics. In further course of pregnancy amniocentesis was performed in 32th week of pregnancy to rule out the infection and to check pulmonal maturity. In absence of infection and lung maturity pregnancy was continued until 36th week of gestation when Cesarean Section was. Baby went well and is now healthy child in the age of three. Some studies suggested that delivery can be significantly prolonged. In our case we managed to gain 14 weeks, from 22th to 36th gestational week. Firstly gynaecologyst nightmare to ask the woman is she accept therapy. The aim is to deliver a healthy child without neurological and other consequences and mother with preserved reproductive function. Controversy still exists when is the appropriate time to finish pregnancy with prolonged PPROM.

Economic analysis of chromosome testing in couples with recurrent miscarriage to prevent handicapped offspring

Which strategy is least expensive to prevent the birth of a handicapped child in couples with recurrent miscarriage (RM); parental chromosome analysis followed by amniocentesis in case of carrier status of one of the parents, or amniocentesis in all ongoing pregnancies without the knowledge of parental carrier status? For virtually all couples with RM amniocentesis in all ongoing pregnancies without the knowledge of parental carrier status is less expensive in preventing the birth of a handicapped child than parental chromosome analysis followed by amniocentesis in case of carrier status of one of the parents. One of the causes of RM is a balanced chromosome abnormality in one of the partners. If one of the partners is carrier of a balanced structural chromosomal abnormality, the risk of offspring with an unbalanced structural chromosome abnormality is increased. Like all couples, couples with RM also have an age-dependent risk for fetal aneuploidy, of which trisomy 21 is most common. Model-based economic analysis to compare costs and effects of two strategies in couples with RM to prevent the birth of a handicapped child in case of ongoing pregnancy. Comparison of two strategies in women with RM: strategy (I) parental chromosome analysis followed by amniocentesis in pregnancy in case of carrier status of one of the parents and strategy (II) amniocentesis in all ongoing pregnancies without the knowledge of carrier status. No testing was the reference strategy. Data on probabilities and costs were derived from the literature. Incremental costs and effects were calculated [incremental cost-effectiveness ratio (ICER)]. Effectiveness was expressed as the number of prevented births of handicapped child equivalents compared with no testing. In these calculations, the birth of a handicapped child was valued 10 times worse than the loss of a viable pregnancy due to amniocentesis. Depending on the risk for carrier status, the ICER for Strategy I (parental chromosome analysis followed by amniocentesis in case of carrier status of one of the parents) varied between € 226,000 and € 6,556,000 per prevented handicapped child equivalent. For Strategy II (amniocentesis in all ongoing pregnancies without the knowledge of carrier status), the ICER varied between € 2000 and € 233 000 per prevented handicapped child equivalent. Strategy I was less expensive than Strategy II only for a small subgroup of couples with maternal age <23 years, three or more previous miscarriages and a family history of RM. Our analysis is not a plea for amniocentesis in all women with RM. Individual risk assessment with serum markers and nuchal translucency is probably more effective at lower cost. This analysis can be used by clinicians to explain the chances of adverse pregnancy outcome in couples with RM, as well as by policy makers in health-care economics. Future guidelines on RM might be more restrictive from the perspective of the limited health-care resources that we have available.

The quadruple test for Down syndrome screening in pregnant women of advanced maternal age

The purpose of the current study was to determine whether or not the quadruple test for screening Down syndrome is an effective method to replace direct amniocentesis in pregnant women ≥ 35 years of age. This study analyzed the screening performance of the quadruple test according to maternal age at delivery among subjects who had a quadruple screening test at 1 of 4 hospitals during a 5-year period and for whom data on fetal chromosomal abnormalities were available. The study population of 9,435 pregnant women was divided into 3 groups according to maternal age: 6,922 women were < 35 years of age; 2,284 were 35-39 years of age; and 229 women ≥ 40 years of age. The detection and false-positive rates of the quadruple screening test for Down or Edward syndrome in the 3 groups of women were 80 and 6.6%, 200 and 15.8%, and 100 and 35.3%, respectively. Under conditions in which first trimester screening test is not available, the quadruple screening test is a better choice than direct amniocentesis for pregnancies complicated by advanced maternal age. When providing genetic counseling, we need to explain the accurate detection and false-positive rates of the screening test according to maternal age.

Diagnóstico prenatal de un caso de trisomía 8 mosaico, asociado a la existencia de un quiste unilateral de plexos coroideos

We report a case of trisomy 8 mosaicism, diagnosed by FISH (fluorescent in situ hibridization) after 18 week pregnancy amniocentesis, in a patient whose ultrasound scan showed a unilateral choroid plexus cyst and placental haemangioma.We assessed the foetopathological examination, comparing it with different cases of total and partial trisomies of chromosome 8, paying special attention to the relationship between choroid plexus cyst and chromosomopathies.

Genetic counselling and amniocentesis in pregnancy by reproductive technology focused on ICSI procedure

Genetic counselling and amniocentesis in pregnancy by reproductive technology focused on ICSI procedure

Chromosomal abnormalities and birth defects among couples with colchicine treated familial Mediterranean fever

To determine whether colchicine prescribed for familial Mediterranean fever is teratogenic. Reproductive histories were analyzed from 326 couples referred for prenatal diagnosis because 1 partner was affected. Numbers of chromosomal abnormalities and birth defects were compared with numbers expected from published rates. There were 901 pregnancies, and amniocentesis had been performed in 566, all but 3 conceived while taking colchicine. Seven numerical chromosomal abnormalities were found, not statistically significantly greater than the 4.99 expected from maternal age and gestation of diagnosis (P = .24): unbalanced structural abnormalities were 6, compared with 3.22 expected (P = .11). There were 7 birth defects, a considerably lower rate than reported in local malformation registers. The current policy of routine amniocentesis in pregnancies of couples taking colchicine should not be changed until sufficient data accumulates to establish whether the higher number of chromosomal anomalies in this group is significant.

Amniotic fluid insulin levels and fetal abdominal circumference at time of amniocentesis in pregnancies with diabetes.

Fetal hyperinsulinism is a strong predictor for excessive growth and fetopathy in pregnancies complicated by diabetes. We examined (i). the relationship between measurements of amniotic fluid insulin (AF insulin) and fetal abdominal circumference (AC) at the time of amniocentesis, and (ii). whether there is a threshold for fetal AC percentiles which can identify low vs. high-risk levels of AF insulin without performing an amniocentesis. In a retrospective study, AF insulin from 121 pregnant diabetic women (32 pregestational; 89 gestational) was measured during the 3rd trimester as part of a diabetes management protocol. AC measurements were transformed into a continuous variable of percentile growth for gestational age (Hadlock). Division of the cohort according to deciles or quartiles of AC percentiles was performed to identify a threshold AC with a significant increase in elevated AF insulin, previously defined as AF insulin >or= 7 microU/ml. A receiver operator characteristic (ROC) curve was created and the negative predictive value (NPV) of the determined threshold was calculated. AF insulin levels were significantly correlated with the AC percentiles (r = 0.3, P = 0.0005) by linear regression. No AC threshold could reliably identify a moderate elevated AF insulin >or= 7 microU/ml (NPV 77.2%), but an AC threshold >or= 75th percentile could identify with fetal hyperinsulinism with an AF insulin >or= 16 microU/ml. All 10 cases of AF insulin >or= 16 microU/ml were identified with a NPV of 100% (74/74). Our data indicate that an AC >or= 75th percentile determined by a 3rd trimester ultrasound examination may discriminate between pregnancies at low vs. high risk for AF insulin >or= 16 microU/ml. This AF insulin concentration corresponds to a level of hyperinsulinism reported to be associated with considerable neonatal and long term morbidity.

Amniocentesis in pregnancies with subchorionic collection

Amniocentesis in pregnancies with subchorionic collection

Equalization of Amniotic Fluid Volumes after Decompression Amniocentesis for Treatment of the Twin Oligohydramnios-Polyhydramnios Sequence

Objective: To measure acute and chronic changes in the placenta and amniotic fluid associated with performance of decompression amniocentesis in pregnancies with the twin oligohydramnios-polyhydramnios sequence (TOPS). Methods: Amniotic fluid pressures, placental thickness, placental perfusion, and amniotic fluid volumes were measured in each sac of a monochorionic diamniotic twin gestation before and after decompression amniocentesis. Indigo carmine was injected into the polyhydramnic sac after decompression, and fluid from the oligohydramnic sac was sampled after equilibration. Spectrophotometric analysis of amniotic fluid specimens was performed for dye detection. Amniotic fluid volume and placental perfusion studies were repeated 1 week later. Results: Three patients with TOPS were enrolled, and decompression amniocentesis was performed in the midtrimester. After decompression, amniotic fluid volume decreased in the polyhydramnic sac, amniotic fluid pressures decreased in both sacs, placental thickness increased, and umbilical artery Doppler velocimetry was unaffected. The amniotic fluid volume increased acutely in only one oligohydramnic sac after decompression, and ultrasonographic examination, amniotic fluid spectrophotometric analysis, and placental pathologic examination all identified interfetal membrane disruption as the etiology. Conclusions: Decompression amniocentesis as a treatment for TOPS does not result in acute or chronic changes in the amniotic fluid volume of the oligohydramnic sac in the absence of interfetal membrane disruption.

Prenatal confirmation of the translocation between chromosome 15 and Y-chromosome by fluorescence in situ hybridization.

A 30-year-old woman and her husband visited our hospital with habitual abortion as the complaint. Chromosome examination revealed a normal 46, XX for her and 46, XY, 15, der (15) t (Y; 15) (q12; p12) for him. After her pregnancy amniocentesis was performed. The karyotype was 46, XX, 15, der (15) t (Y; 15) (q12; p12) pat. ish der (15) (DYZ1+). A female baby was delivered. The growth of the baby was normal at 12 months of age.

Stuck twin syndrome: Outcome in thirty-seven consecutive cases

Our purpose was to further evaluate the role of serial amniocentesis in pregnancies complicated by the "stuck twin" syndrome. A cohort of 37 consecutive cases of stuck twin syndrome was followed up from 1986 through 1992. Evaluations included gestational age at diagnosis and at delivery, mean number of amniocenteses, volume of amniotic fluid withdrawn, placentation, perinatal complications, fetal survival, and neonatal follow-up. Five pregnancies were terminated, five had no intervention, and 27 underwent serial amniocenteses. The mean number of amniocenteses was 3.4 (range 1 to 6), and mean total amniotic fluid volume withdrawn was 5.8 L (range 0.75 to 4.0). In the serial amniocentesis group mean gestational age was 23.1 weeks (range 16 to 30) at diagnosis and 31.5 weeks (range 20 to 38) at delivery. Eighty-two percent had monochorionic placentas, and 36% had marginal or velamentous cord insertions. Infant survival was 39 of 54 (74%) in the serial amniocentesis group compared with four of 10 (40%) in the nonintervention group (relative risk 0.46, 95% confidence interval 0.24 to 0.90). Serial amniocentesis was associated with a 54% reduction in fetal and neonatal death in cases of stuck twin syndrome.

Fertilität und Turner-Mosaik-Syndrom

Six patients with a Turner mosaicism are reported. All six women were investigated for sterility or infertility. Four of six patients had a total of nine pregnancies: six abortions, one stillbirth, two normal children. The literature contains reports of 17 pregnancies in 10 women with 45.X karyotype and 106 pregnancies in 48 women with mosaicism. Miscarriages, stillbirths and malformations were common. These women need special counselling and in case of a pregnancy amniocentesis is indicated. We discuss the pathogenesis of reduced fertility with Turner patients and explain the problems related to the cystogenetic diagnosis of the Turner-Mosaic Syndrome.

Prenatal diagnosis policy without routine amniocentesis in pregnancies with a positive family history for neural tube defects

The recurrence risk for neural tube defects in pregnancies of women with a family history of neural tube defects greatly exceeds the general population risk. In these high risk pregnancies, we used a prenatal diagnostic method differing from that usually employed, relying mainly on the results of maternal serum alpha-fetoprotein (MSAFP) and ultrasound examination, without routine amniocentesis. During the 6 years reviewed in this study, this method was applied in 539 pregnancies. Of a total of 20 neural tube defects, 19 were detected using this combination of MSAFP, ultrasound, and selective amniocentesis, and the authors estimate that about 8-10 spontaneous abortions were avoided because only 28 amniocenteses were carried out instead of 539. The risk of recurrence was found to be lower than that experienced earlier.

Prenatal diagnosis of Meckel syndrome: alpha-feto protein and beta-trace protein in amniotic fluid.

Meckel syndrome was diagnosed prenatally by alpha-feto protein and beta-trace protein determinations in amniotic fluid. No central nervous system anomalies were detected in the affected fetus, who presented with large polycystic kidneys and polydactyly. An excessive synthesis of these fetal proteins by the dysplastic kidneys is suggested, allowing for the possibility of prenatal diagnosis of polycystic kidneys in families at risk for this disease. The present family emphasized the importance of amniocentesis in pregnancies at risk for Meckel syndrome, regardless of the presence of a defect in neural tube closure.