Impacto de la introducción en el primer trimestre del cribado combinado de trisomía 21 en la tasa de procedimientos invasivos

Objective

To study the impact of introducing first-trimester combined Down syndrome screening on invasive prenatal testing for prenatal diagnosis, together with the criteria change from 35 to 38 years old as the indication for obtaining the fetal karyotype.

Material and methods

A retrospective population-based study was carried out of invasive tests for prenatal diagnosis performed at the Cabueñes Hospital in Gijón (Spain). A first period from 31-1-2004 to 30-1-2006 (without the screening program) was compared with a second period from 31-1-2006 to 30-1-2008 (with the screening program). During the second period the impact of screening (31-1-2006 to 30-1-2007) was differentiated from that linked to changing the maternal age criteria to 38 years old as the indication for invasive testing (31-1-2007 to 30-1-2008).

Results

During the second period there was an overall reduction of 31.2% in invasive testing; 21.6% was exclusively attributable to first-trimester combined Down syndrome screening. In expectant mothers aged 35 or more at delivery, the number of amniocentesis performed in the second period was reduced by 30.74%; this tendency was maintained for pregnant women aged 38 years or more, showing a reduction of 25.92%. In the second period, 30% of the expectant mothers aged 38 years or more chose to have an invasive test due to their age compared with 61.53% in the first period.

Conclusions

First-trimester combined Down syndrome screening had a major impact on invasive testing, increasing its efficiency and, moreover, allowing detection rates to be improved.     

Efectividad del doble test bioquímico como prueba de cribado de síndrome de Down en el segundo trimestre

Several screening tests are available to identify the population at risk of Down syndrome. This population should then be recommended to undergo an invasive technique to obtain a fetal karyotype. In our hospital, screening is done by the combined test (maternal age + nuchal translucency + β subunit of human chorionic gonadotropin [β-HCG] + pregnancy-associated plasma-A [PAPP-A]) during the first trimester of pregnancy. When this test is not feasible, we request the double test (alpha-fetoprotein [AFP] + β-HCG) as a second trimester screening test.The results of the double test in our hospital were unsatisfactory because the detection rate was 0% with a false positive rate of 7.7%. Therefore, we believe alternative criteria should be used to select women at risk of having a child with Down syndrome in the second trimester.     

Cribado de aneuploidía en gestación gemelar: resultados de la aplicación del test combinado

Objective

To evaluate the effectiveness of the Combined Test for trisomy 21 screening in twin pregnancies. To assess the performance of biochemical markers and nuchal translucency (NT) measurement in pregnancies with euploid fetuses and in twin pregnancies with one or two affected fetuses. To compare the value of markers according to chorionicity and the mode of conception.

Material and methods

Retrospective study including 161 twin pregnancies. Maternal serum fß-hCG and PAPP-A were determined at 8 to 12 weeks and fetal NT was measured at 11 to 14 weeks. The individual risk of trisomy 21 was calculated in each fetus using the Combined Test. In monochorionic pregnancies, the single risk for the pregnancy was obtained with the largest NT. An invasive diagnostic procedure was offered when the risk was 1:250 or more in one or both of the fetuses.

Results

All trisomy 21 pregnancies were identified (three pregnancies and four fetuses) by the combined testfor a false-positive rate of 6.4% of pregnancies and 3.5% of fetuses. The median fß-hCG level, expressed in MoM, was 1.72 and the median PAPP-A level was 2.01. The median NT was 1.05 MoM. Both fß-hCG and PAPP-A levels were significantly decreased in monochorionic pregnancies and PAPP-A was significantly decreased in pregnancies resulting from assisted reproduction. No significant differences were observed in NT measurement between monochorionic and dichorionic fetuses or between those conceived naturally or by assisted reproduction.

Conclusions

The combined test shows high sensitivity and specificity in screening for trisomy 21 in twin pregnancies. The differences obtained in the biochemical markers according to chorionicity or the mode of conception require confirmation in further studies with a larger number or cases.     

Cribado combinado del síndrome de Down: validación del riesgo estimado por Fetaltest

Objective

To validate empirically the risk for Down syndrome estimated by Fetaltest using biochemical markers in the first trimester (PAPP-A and free beta subunit of hCG) and nuchal translucency.

Material and methods

We performed a retrospective study of the data from 15,009 pregnant women screened for Down Syndrome in the first trimester, included in the database prospectively maintained by the Fetaltest multicenter study, and completed before December 31, 2007. The study included 39 cases of Down syndrome detected either prenatally or postnatally, and used a previously established analysis method.

Results

The correlation between predicted risk and the observed prevalence of Down syndrome was very high (r = 0.999967).

Conclusions

The risk estimated by Fetaltest agrees closely with the observed prevalence of Down syndrome. Therefore, this calculation system is valid and can be used with confidence when counseling pregnant women in our environment.     

Cribado combinado para la detección de trisomía 21 en el primer trimestre de la gestación. Impacto sobre la tasa de procedimientos invasivos de diagnóstico prenatal tras 5 años de implementación

Objective

To assess the effectiveness of first-trimester combined screening in the prenatal detection of Down syndrome after 5 years of use in our hospital and its impact in reducing invasive diagnostic tests.

Material and methods

The risk of fetal chromosomal anomalies was assessed in 10,669 pregnancies with first-trimester combined screening between May 2006 and December 2010. The cut-off to indicate an invasive diagnostic test was 1/270. The amniocenteses performed between 2005 and 2010 were also analyzed.

Results

The detection rate of screening for trisomy 21 was 90% and the false-positive rate was 3.56%. In pregnant women aged 35 years or more, the detection rate was 96.7%. In 2005 there were 496 amniocenteses. In 2010, 5 years after the introduction of screening, 148 amniocenteses were performed, representing a 70% reduction in invasive procedures.

Conclusions

The introduction of combined screening in our environment has proven effective for the detection of trisomy 21 and has substantially reduced the use of invasive prenatal diagnostic procedures. The use of advanced maternal age as an isolated criterion to indicate invasive techniques to study fetal karyotype should be questioned if high-quality universal screening is to be offered.     

Resultados obstétricos en cribado combinado de las aneuploidías en el primer trimestre superior al corte con resultado de amniocentesis con cariotipo fetal normal

Introduction

To evaluate whether there are adverse pregnancy outcomes in pregnant women with a risk index above the cut-off point in first-trimester screening for fetal chromosomal abnormalities and an amniocentesis result of normal fetal karyotype in a sample of pregnant women attending our clinic at the beginning of pregnancy.

Subjects and methods

We performed a case-control study. A series of patients who underwent first-trimester combined screening as part of antenatal care between January 2009 and January 2010 were selected.

Results

Of the maternal complications registered during the pregnancy, gestational diabetes was more frequent among cases.

Conclusions

The incidence of the remaining complications analyzed (intrauterine restricted growth, preeclampsia, oligoamnios) was similar in the two groups. In most of the pregnant women, delivery occurred after 37 weeks through the vaginal route.     

Cribado cromosómico del primer trimestre. Resultados en gestaciones tras reproducción asistida

Objective

To determine the effectiveness of the combined test for aneuploidies in the first trimester of spontaneous pregnancies in comparison with pregnancies following assisted reproductive technology (ART).

Materials and methods

We performed a retrospective study of 1675 triple tests performed in the first trimester in our center, including pregnancy-associated plasma-A (PAPP-A) and the free fraction of the β subunit of human chorionic gonadotropin (free β-hCG), maternal age and nuchal scan. Of these, 1299 (77.5%) were spontaneous pregnancies and 376 (22.5%) were pregnancies following ART. The cut-off point for recommending an invasive test was 1/270.

Results

The combined test was carried out in 74 twin pregnancies, with two false-positive results. Among single pregnancies, 70 positive triple tests were obtained, 3.79% of spontaneous pregnancies and 6.84% of ART pregnancies. Eleven chromosomal abnormalities were found, nine in spontaneous pregnancies and two in ART pregnancies. The sensitivity of the test was 89% in spontaneous pregnancies and 100% in ART pregnancies. The specificity was 96% and 93.77%, respectively.

Conclusions

The first trimester triple test has high sensitivity and specificity in single pregnancies, whether spontaneous or following ART. The rate of positive triple tests is higher in pregnancies following ART.     

Translucencia nucal y ductus venoso: valores de referencia en el primer trimestre de la gestación

Objective

To establish the reference ranges for nuchal translucency (NT) and ductus venosus (DV) pulsatility index for veins (PIV) in our population.

Methods

During a 4-year period, pregnancies originated from the general population undergoing 11.1-14.0 weeks ultrasound examination were studied. Reference intervals were constructed following the methodology described by the National Committee for Clinical and Laboratory Standards. According to the conclusion of the partition test, gestational age-related reference intervals were estimated using linear regression models for the NT. Deviances from linearity in the estimated models were evaluated using fractional polynomials of 1st or 2nd degree.

Results

2,612 pregnancies were studied. No significant differences were found for DV PIV between gestational age groups. There was a significant difference of the NT values between age groups (p < 0.001) and the gestational age-related estimation of reference intervals showed a no-linear increase.

Conclusion

A significant increase was found for NT with gestational age, whereas the DV PIV remained constant.     

Inseminación artificial intrauterina en mujeres con síndrome de ovario poliquístico resistentes al citrato de clomifeno

Objective

To evaluate the results of ovulation induction cycles with gonadotropins and intrauterine insemination (IUI) carried out in women with polycystic ovary syndrome (POS) resistant to clomiphene citrate.

Material and methods

We performed an observational retrospective study of 462 ovulation induction cycles with IUI in women with SOP and clomiphene citrate resistance.

Results

The clinical pregnancy rate was 11.9% per cycle initiated and 14.74% per insemination and 45.45% of the pregnancies terminated in abortion. The effective accumulative percentage of term pregnancies per cycle initiated was 8% for the first cycle and 10.23% for insemination, increasing to 26.15% from the fifth cycle and to 32.24% from the fifth insemination. A total of 19.26% of the cycles was cancelled.

Conclusions

IUI is a useful method in women with SOP who are resistant to clomiphene citrate, with similar results to those obtained with other indications. These patients have high abortion and cycle cancellation rates. The high abortion rate should prompt research into ways of reducing reproductive loss.     

Amniocentesis genéticas durante los últimos 6 años en nuestro hospital

Introduction

Identification of fetal congenital chromosomal abnormalities is undoubtedly one of the main challenges faced by obstetricians involved in the prenatal diagnosis of congenital anomalies.

Objective

To evaluate the diagnostic yield of genetic amniocentesis in our hospital and its associated complications.

Patients And Methods

We performed a retrospective analysis of all genetic amniocenteses performed in our hospital in the last 6 years, focusing on diagnostic yield, the most common associated complications, and the indications for this procedure. We also reviewed the various population-based screening programs currently applied.

Results

The main indication for amniocentesis was maternal age-associated risk. A total of 2.161% of procedures led to diagnosis of chromosomal abnormalities, with a complications rate of 1.028%.

Conclusion

Although our results are similar to those reported in other published series, current screening strategies should be revised, mainly in older pregnant women.     

Síndrome de Meckel. Diagnóstico prenatal y diagnóstico diferencial

Meckel syndrome is an infrequent and lethal syndrome characterized by multiple malformations. Inheritance is autosomal recessive. The incidence of this syndrome ranges from 1:1,300 to 1:140,000 births. The most common malformations are those affecting the central nervous system (usually occipital meningoencephalocele), bilateral renal cystic dysplasia, fibrotic changes of the liver and polydactyly. The associated genomic alteration can involve distinct loci. Prenatal diagnosis is feasible with ultrasound findings and, in numerous cases, with fetal DNA analysis. We present the case of a woman who had two consecutive pregnancies with a diagnosis of Meckel syndrome.     

Síndrome obstructivo congénito de las vías aéreas altas (síndrome de CHAOS). Causa infrecuente de hídrops fetal

Congenital high airway obstruction syndrome (CHAOS) is an uncommon malformation. Prenatal diagnosis of this malformation by ultrasound has previously been described. Prenatal identification will allow us to offer patients the possibility of prenatal counseling and to substantially improve perinatal outcomes in comparison with those in fetuses without a prenatal diagnosis, in which emergency maneuvers must be performed with unpredictable results. Currently, most of the cases described in the literature correspond to pregnancies with a prenatal diagnosis, which has allowed cesarean section to be successfully performed with the EXIT procedure (ex utero intrapartum treatment). Excellent results have sometimes been obtained.     

Prevención de la hemorragia posparto en una gestante afectada de síndrome de Hermansky-Pudlack

Hermansky-Pudlak syndrome is a multisystemic disease with autosomal recessive inheritance, mainly characterized by oculo-cutaneous albinism and impaired platelet aggregation. We describe the follow–up and end of pregnancy in a 30-year-old woman with this syndrome, as well as the measures carried out during labor to avoid bleeding complications due to platelet dysfunction. The pregnancy ended at 38.2 weeks through vaginal delivery, without epidural anesthesia and good maternal and fetal outcome.     

Síndrome de Fraser

The Fraser syndrome is an infrequent recessive autosomal disease. Two major criteria and one minor criterion or one major and at least four minor criteria are required for the diagnosis (provided by Thomas et al in 1986). We present the case of a newborn with Fraser syndrome, born after a no - risk pregnancy, that was not detected before the delivery. This case shows numerous diagnostic criteria (cryptophthalmos, syndactyly, abnormal genitalia...) and some very infrequent malformations as a part of this syndrome as the ovarian absence. We should think about this syndrome when the ecography shows oligohydramnios, hyperechogenic and voluminous lungs, renal agenesis and/or ocular malformations.     

Control de calidad de la translucencia nucal. Experiencia en 6 centros del ámbito de primaria

Objective

To apply quality control to nuchal translucency (NT) measurements in the scans performed in two primary care health regions (Vallès and Centre de Catalunya) in Catalonia, Spain.

Subjects and methods

We evaluated 7,386 TN measured in 2009 in the prenatal care centers of two health areas (Vallès and Centre de Catalunya) of the Catalan health service. We applied two methods of quality control: the method proposed by the Fetal Medicine Foundation (FMF) and that proposed by the Women and Infants’ Hospital, Rhode Island (WIHRI) group.

Results

The FMF method showed that 68% of sonographists underestimated NT when the 50^th percentile was assessed. For the 95^th and 5^th percentiles, the underestimation rates were 89% and 32%, respectively. When the WIHRI method was applied to the overall series, all parameters were within the normal range. Results by individual sonographists showed that 43% underestimated the median value of the multiple of the median (MoM) measurements.

Conclusions

NT quality control was not useful when applied to the entire series. Instead, its application in individual sonographists allows those that significantly deviate from the expected values to be identified and corrections to be proposed.     

Trombosis del seno venoso cerebral en gestante con síndrome de Job

Cerebral venous sinus thrombosis is uncommon. Pregnancy is a major risk factor for the development of this entity. We report the case of a patient with Job’s syndrome and protein C and S deficiency who developed cerebral venous sinus thrombosis and dural fistula at 36 weeks’ gestation. After heparinization, the treatment of choice, pregnancy termination to eliminate the prothrombotic status and embolization of the dural fistula were required to obtain complete remission of the neurological symptoms.     

Adenoma de células de Sertoli bilateral en paciente con síndrome de insensibilidad a los andrógenos

Androgen insensitivity syndrome is characterized by the presence of a female phenotype, masculine gonads, and 46,XY karyotype. This syndrome is the most common cause of masculine pseudohermaphroditism and is the third most frequent cause of primary amenorrhea after gonadal dysgenesis and congenital absence of the vagina. The importance of this entity lies in its early diagnosis in puberty because of the risk of testicular tumors. In this article, we present a case of late diagnosis of androgen insensitivity syndrome related to Sertoli cell adenoma.     

Cribado de parto pretérmino en el primer trimestre de la gestación

First-trimester combined screening for preterm delivery and the early initiation of preventive strategies in high-risk patients can effectively reduce preterm delivery rates.