Late Amniocentesis Research Articles

Comparative analysis of the application with the combination of CMA and karyotype in routine and late amniocentesis.

This is a retrospective comparative study. We aimed to analyze the results of karyotype and chromosomal microarray analysis (CMA) of amniotic fluid across different gestational weeks and evaluate the clinical value in prenatal diagnosis, particularly in the late pregnancies. Samples from 580 pregnant women of 18-23weeks of gestation (mid-gestation group) and 196 pregnant women of 24-32weeks of gestation (late group) were performed both standard G-band karyotype analysis and CMA. Among the 580 pregnant women in the routine group, the most common indications were positive Down's screening (213/580, 36.7%), followed by advanced maternal age (196/580, 33.8%); while fetal structural anomalies on ultrasonography were the top reason for amniocentesis in the late group (56/196, 28.6%). In the routine group, the total detection rate was 12.1% (70/580), of which 4.1% (24/580) were identified by karyotype analysis and 11.2% (65/580) by CMA. The total detection rate was 15.3% (30/196) in the late group, of which 5.1% (10/196) were detected by karyotype analysis, and 14.3% (28/196) by CMA. Karyotype analysis and CMA are complementary in detecting chromosomal abnormalities. Amniotic cavity puncture in the karyotype analysis in 18-23weeks of gestation and 24-32weeks of gestation is safe and effective, more obvious effect on the latter.

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.

Obstetrical outcomes following amniocentesis performed after 24weeks of gestation: A systematic review and meta-analysis.

To evaluate obstetrical outcomes for women having late amniocentesis (on or after 24weeks). Electronic databases were searched from inception to January 1st, 2023. The obstetrical outcomes evaluated were gestational age at delivery, preterm birth (PTB)<37weeks, PTB within 1week from amniocentesis, premature prelabor rupture of membranes (pPROM), chorionamnionitis, placental abruption, intrauterine fetal demise (IUFD) and termination of pregnancy (TOP). The incidence of PTB <37weeks was 4.85% (95% CI 3.48-6.56), while the incidence of PTB within 1week was 1.42% (95% CI 0.66-2.45). The rate of pPROM was 2.85% (95% CI 1.21-3.32). The incidence of placental abruption was 0.91% (95% CI 0.16-2.25), while the rate of IUFD was 3.66% (95% CI 0.00-14.04). The rate of women who underwent TOP was 6.37% (95%CI 1.05-15.72). When comparing amniocentesis performed before or after 32weeks, the incidence of PTB within 1week was 1.48% (95% CI 0.42-3.19) and 2.38% (95% CI 0.40-5.95). Amniocentesis performed late after 24weeks of gestation is an acceptable option for patients needing prenatal diagnosis in later gestation.

Late amniocentesis: better late than never? A single referral centre experience.

Several congenital abnormalities present late in pregnancy necessitating invasive testing to rule out genetic/infectious causes at late gestation. Not many studies have described the indications/safety of a late gestation amniocentesis. All records of amniocentesis performed beyond 24weeks were reviewed and evaluated for indications, positive yield and complications. About 187 women had an amniocentesis after 24weeks for various indications with CNS abnormalities beingthe commonest. The total yield of positive findings was 14.60% (22/150; excluding 2 VOUS). CNS, multiple system involvement and skeletal system anormalities yielded maximum results. About 32.05% abnormalities could have potentially been detected at the time of a routine anomaly scan. Amongst all the deliveries, 2.1% delivered spontaneously within a week of the procedure and about 5.4% delivered spontaneously within a month of the procedure. The study emphasises the need for additional accreditation (FMF, ISUOG) of sonographers to ensure the detection of anomalies at the routine 18-20weeks scan. Inspite of a normal mid-trimester scan, central nervous system and gastrointestinal abnormalities presented more commonly after 24weeks. The high positive yield in our study highlights the importance of testing even in late pregnancy beyond the legal age of termination. The test could clearly stratify the pregnancies with a poor outcome whilst reassuring the others. The procedure itself did not lead to a neonatal death due to prematurity.

The application of late amniocentesis: a retrospective study in a tertiary fetal medicine center in China

BackgroundTo assess the indications and complications of late amniocentesis and the advanced genetic test results in a tertiary university fetal medical medicine unit.MethodsIn this retrospective study, women that underwent amniocentesis at 24+ 0 to 39+ 4 weeks, between January 2014 and December 2019, were recruited. Indications, complications, genetic test results, and pregnancy outcomes were reported for each pregnancy and compared with those who underwent the traditional amniocentesis at 16+ 0 to 23+ 6 weeks (control group). Information was retrieved from patient medical records, checked by research staff, and analyzed.ResultsOf the 1287 women (1321 fetuses) included in the late amniocentesis group, late detected sonographic abnormalities (85.5%) were the most common indication. The overall incidence of preterm birth and intrauterine demise after amniocentesis were 2.5 and 1.3%, respectively. Sixty-nine fetuses with aneuploidy (5.3%) and seventy-two fetuses with pathogenic copy number variations (5.5%) were identified by chromosomal microarray analysis. The maximal diagnostic yield (70%) was in the subgroup of fetuses with the abnormal diagnostic test results, followed by abnormal NIPT results (35.7%) and multiple abnormalities (23.8%). And 35.4% of the pregnancies were finally terminated.ConclusionsDue to the high detection rates of advanced genetic technologies and the safety of the invasive procedure (3.9% vs 4.0%), it is reasonable to recommend late amniocentesis as an effective and reliable method to detect late-onset fetal abnormalities. However, chromosomal microarray and whole-exome sequencing may result in uncertain results like variants of uncertain significance. Comprehensive genetic counseling is necessary.

477 Procedure-to-delivery interval after late amniocentesis and the need for routine antenatal corticosteroids

The aim of this study is to assess the procedure-to-delivery interval (PDI), the obstetric complications, and the early neonatal outcome in patients that did or did not receive glucocorticosteroids before third-trimester amniocentesis. A retrospective analysis of 445 third-trimester amniocentesis (TTA) procedures divided into two groups based on the administration (study group = 220 patients) or not (control group = 225 patients) of glucocorticosteroids before TTA. The PDI was calculated for all patients. Obstetric and neonatal outcomes were compared between the groups The rate of procedure-associated complications was similar between the groups. The mean PDI was 47.2±16.8 days. The overall incidence of preterm birth was 11.7%; 9% delivered between 34 and 37 weeks and 2.7% between 28 and 34 weeks. Only nine patients (2%) delivered within seven days following TTA. The incidence of respiratory distress syndrome in the study and control groups was 1.8% and 1.3%, p=0.71, respectively. There were no significant differences in other neonatal outcomes in term and preterm deliveries between the study and control groups. In the present study, the administration of glucocorticoids prior to TTA did not reduce the rates of neonatal complications, which was similar in both groups and not higher than the general population.

Procedure-to-delivery interval after late amniocentesis and the need for routine antenatal corticosteroids

Objectives The aim of this study is to assess the procedure-to-delivery interval (PDI), the obstetric complications, and the early neonatal outcome in patients that did or did not receive glucocorticosteroids (GCSs) before third-trimester amniocentesis (TTA). Methods A retrospectively analysis of 445 TTA procedures divided into two groups based on the administration (study group = 220 patients) or not (control group = 225 patients) of GCSs before TTA. The PDI was calculated for all patients. Obstetric and neonatal outcomes were compared between the groups. Results The rate of procedure-associated complications was similar between the groups. The mean PDI was 47.2 ± 16.8 days. The overall incidence of preterm birth was 11.7%; 9% delivered between 34 and 37 weeks and 2.7% between 28 and 34 weeks. Only nine patients (2%) delivered within seven days following TTA. The incidence of respiratory distress syndrome in the study and control groups was 1.8% and 1.3%, p = .71, respectively. There were no significant differences in other neonatal outcomes in term and preterm deliveries between the study and control groups. Conclusions In the present study, the administration of glucocorticoids prior to TTA did not reduce the rates of neonatal complications, which was similar in both groups and not higher than the general population.

VP06.08: The application of late amniocentesis: a retrospective study in a tertiary fetal medicine centre in China

VP06.08: The application of late amniocentesis: a retrospective study in a tertiary fetal medicine centre in China

An observational study to assess Italian obstetrics providers' knowledge about preventive practices and diagnosis of congenital cytomegalovirus.

Congenital cytomegalovirus (cCMV) infection can be easily prevented by hygienic measures. Up to date the majority of the studies in literature highlighted a reduction in cCMV antenatal counseling and its prevention. Our purpose was to evaluate obstetrics providers' knowledge about cCMV infection, management and the behavioral practices to avoid it. This is a cross-sectional survey carried out in Umberto I Hospital, "Sapienza" University of Rome between November 2019 and January 2020. We recruited 148 specialists and residents in Obstetrics and Gynecology through online anonymous multiple-choice 13-questions, 10min-survey comparing responses between the two groups. A total of 94.6% of all participants said they always prescribe cytomegalovirus (CMV) serum screening: 73.6% of them regularly counsel about preventive practices, with specialists recording higher percentages (85.4 vs. 65.1%, p<0.005). We identified a good knowledge about the diagnostic pathway, but only 58.1% of our population knows the correct time of late amniocentesis. 12.2% of providers do not consider magnetic resonance (MRI) as a complementary exam. Prevention of maternal seroconversion is crucial: even if our data show an acceptable knowledge about antenatal counseling, we encourage clinicians to firmly inform and educate women about behavioral measures.

Valacyclovir in primary maternal CMV infection for prevention of vertical transmission: A case-series

BackgroundNo treatment is currently approved for cytomegalovirus infection in pregnancy. Valacyclovir has been studied in symptomatic cytomegalovirus infected fetuses and seems to reduce the risk of serious sequelae. ObjectivesWe used off-label valacyclovir on pregnant women with primary cytomegalovirus infection to reduce the risk of fetal infection. Study designWe treated 12 pregnant women with 8 g/day valacyclovir after diagnosis of cytomegalovirus infection until amniocentesis. We continued treatment until delivery in case of fetal infection. We periodically performed serology and virology tests on the women from referral until delivery and monitored them for adverse effects while on treatment. All women underwent late amniocentesis. We followed up infants for 5–28 months. ResultsAt the time of amniocentesis, we observed a transmission rate of 17 %, and at birth we observed a transmission rate of 42 %. Two women with negative amniocentesis and infected newborns had viremia reactivation after valacyclovir discontinuation. We observed no symptomatic infections at birth and one isolated sensory-neural hearing loss at follow-up. ConclusionsThis is the first series of antiviral treatment in women with a diagnosis of cytomegalovirus infection before amniocentesis. Valacyclovir may control cytomegalovirus infection while it is administered and reduce transmission at amniocentesis. Late transmission after treatment discontinuation is a risk. We advocate the need for a controlled trial of valacyclovir therapy starting from diagnosis of maternal infection until delivery, regardless of prenatal diagnosis of infection.

P15.01: Procedure‐to‐delivery interval after late amniocentesis (28 and 33 weeks): is there a rationale in giving glucocorticoids prior to the procedure?

P15.01: Procedure‐to‐delivery interval after late amniocentesis (28 and 33 weeks): is there a rationale in giving glucocorticoids prior to the procedure?

The yield and complications of amniocentesis performed after 24 weeks of gestation.

This study assessed the use and complications of late amniocentesis (AC) and analyzed factors that affect complication rate. A retrospective analysis of 167 genetic AC performed after 24weeks during a 10-year period in two medical centers was conducted. Data regarding the indications for AC, genetic work-up, and pregnancy outcomes were retrieved from patient medical records and telephone-based questionnaires. Mean gestational age (GA) at the time of AC was 31.7±2.7weeks; 104 procedures were performed at ≤32weeks, including 24 at ≤30weeks. The overall pregnancy complication rate occurring at any time after the procedure was 6.6% (11). Of these, 4.8% (8) occurred within a month after AC, including 2.4% (4) that occurred within a week. An additional three occurred after 30days. There were no differences in the total complication rate and in the rate of specific complications of procedures performed at ≤32weeks or at ≤30weeks. Maternal age did not affect outcomes. Genetic testing was abnormal in five cases (3%). Amniocyte culture failed in 3 cases (2.3%), with no technical failures in 52 chromosomal microarray tests. The complication rate of AC performed after 24weeks was 4.8%, which is significantly higher than that of second trimester AC. GA and maternal age did not affect the complication rate.

OC20.06: Late amniocentesis: is our counselling up to date?

OC20.06: Late amniocentesis: is our counselling up to date?

OP12.01: The impact of late amniocentesis in the era of genomic technology

OP12.01: The impact of late amniocentesis in the era of genomic technology

PFM.16 Third trimester amniocentesis for inherited bleeding disorders can be used to inform delivery management for at risk male fetuses

Haemophilia A and B can cause significant bleeding in affected males. Labour management of a potentially affected male should be cautious due to the potential risk of fetal haemorrhage, with...

Pregnancy Outcomes after Late Second Trimester Amniocentesis for Prenatal Diagnosis

Objective: To compare the rate of preterm delivery in patients who had an amniocentesis before and after 20 weeks gestation. Study Design: This is a single-center retrospective cohort study of patients referred for specialized sonogram between January 1, 2007 and December 31, 2009. Outcomes of patients who underwent amniocentesis at less than 20 0/7 weeks were compared to those who had amniocentesis on or after 20 0/7 weeks. Results: 1041 patients met the inclusion criteria, and 290 (27.9%) underwent amniocentesis. Women were younger in the late amniocentesis group and were more likely to be African-American. Gestational age at delivery, rate of preterm birth,, and birth weight did not differ between the two groups. In a multivariate analysis, gestational age at amniocentesis was not a significant factor for gestational age at delivery. Conclusion: Amniocentesis performed after 20 weeks gestation appears to be safe. This study provides reassuring information regarding late amniocentesis.

Third trimester amniocentesis for diagnosis of inherited bleeding disorders prior to delivery

X-linked and autosomally inherited bleeding disorders confer a risk of foetal intracranial haemorrhage during delivery. Conventional prenatal diagnosis involving chorionic villus sampling or early amniocentesis is primarily aimed at offering the choice of pregnancy termination. Currently, non-invasive procedures, involving analysis of free foetal DNA in the maternal circulation, are restricted to gender determination, and are of limited value in women at risk of carrying a foetus with a bleeding disorder. These limitations, together with the rising proportion of women shown to be carrying an affected foetus, who decide to continue the pregnancy, have led to the development of prenatal mutation identification via late amniocentesis after 34 weeks of gestation, with the sole aim of directing delivery management. Although this approach has been documented in some cases of potential foetal anomaly, there are no previous reports of its use in women with heritable bleeding disorders. We report a single-centre experience of this technique in managing nine such deliveries. Of these, three showed an affected foetus, five showed an unaffected foetus and in one case no result could be obtained. In the three affected cases and the one with the inconclusive result restrictive birth plans were implemented, whereas the five unaffected cases underwent routine obstetric management; with one delivery necessitating interventions which would have been contraindicated if foetal status had not been determined. Late amniocentesis is a safe technique for guiding delivery management in women with bleeding disorders where the mutation is known.

The incidence of Down syndrome in newborns at the Department of Obstetrics and Gynecology of the Clinical center Kragujevac during the period 2007-2012

Objective. The main objective of this study was to determine the incidence of Down syndrome in newborn infants diagnosed prenatally and in newborn children in Kragujevac. Methods. This retrospective study included groups of 1208 pregnant women and 10,712 mothers aged 14-55 years, who came to the Gynecology and Obstetrics Clinic, Clinical Center Kragujevac during the period 2007-2012. Cells of amniotic fluid, taken during amniocentesis between 16 and 18 weeks of pregnancy, were cultured for 12 days and, after cytogenetic processing, stained and analyzed with light microscopy. Data were analyzed and presented descriptively. Results. During the four year period, between January 2007 and December 2011, 8 cases of Down syndrome were diagnosed by amniocentesis of 1208 amnions, which resulted in incidence of 1 in 151 amnions. Also, there were 15 cases of liveborn children with Down syndrome in 10822 liveborn babies, which made an incidence of 1 in 721 liveborns. The total of 1070 pregnancies were with mothers older than 35 years at the time of labor and 5 of 15 liveborn babies with Down syndrome were from mothers belonging to this group. Also, 9464 pregnancies were with mothers aged 18-35 years and in this group there were the last 10 cases of Down syndrome. There were 8 fetuses with Down syndrome, all diagnosed with trisomy 21, and all 8 aborted by choice of the Ethical committee of the Clinical Center Kragujevac. Conclusion. The decision of not having prenatal diagnostics for pregnancies, some by late amniocentesis, some by the decision of the family, resulted in Down syndrome liveborns.

The Role of Late Amniocentesis in the Management of Preterm Parturition

The Role of Late Amniocentesis in the Management of Preterm Parturition

Third trimester amniocentesis: a tool to aid choices concerning place of delivery and intrapartum management in haemophila carriers

Haemophilia A is an X linked recessive disorder with an annual incidence of 1 in 5,000 live male births.We report the case of a G2P1+0 (previous normal vaginal delivery), a...