Impact on spina bifida screening of shifting prenatal Down syndrome maternal serum screening from the second trimester to the first.

OBJECTIVES: Shifting screening for trisomy 21 to the first trimester has resulted in the loss of maternal serum alpha-fetoprotein screening for spina bifida. The aim of this study was to study the impact on open spina bifida prenatal screening. STUDY DESIGN: We reviewed prenatally diagnosed cases of spina bifida over three years: 2009 (only second-trimester screening, MSM2T), 2010 (transient period) and 2011 (majority first-trimester screening, MSM1T). Cases were assigned to three groups based on maternal serum markers (MSM2T, MSM1T and 'not performed'). Gestational age at diagnosis of spina bifida was compared between these three groups and between the years 2009 and 2011. RESULTS: Median gestational ages at diagnosis of the 742 spina bifida cases between the three groups were 22 weeks [18+6 -23], 22+1  weeks [21+3 -23] and 21+4  weeks [14+1 -23], respectively (P < 0.005). The diagnosis was made at 14-20 weeks in 34.7% for MSM2T group versus 8.5% for MSM1T (P < 0.001). Spina bifida diagnosis at 14-20 weeks declined from 38.8% in 2009 to 13.3% in 2011 (P < 0.001). CONCLUSION: Loss of maternal serum alpha-fetoprotein had a tangible effect on the gestational age at diagnosis of spina bifida and resulted in a decrease of 25% of cases of spina bifida detected before 20 weeks. © 2017 John Wiley & Sons, Ltd.

Prenatal diagnosis of Bartter syndrome: amniotic fluid aldosterone.

OBJECTIVE: Bartter syndrome is a severe inherited tubulopathy characterized by postnatal salt wasting, severe polyuria, dehydration, failure to thrive and secondary hyperaldosteronism. Prenatally, the disease is usually discovered following the onset of severe polyhydramnios in the second trimester. We studied amniotic fluid aldosterone concentration in Bartter syndrome and in controls. METHODS: Amniotic fluid aldosterone was assayed by radioimmunoassay. We undertook a retrospective case-control study based on 36 cases of prenatally suspected and postnatally confirmed Bartter syndrome (22 with identified mutations): and 72 gestational age matched controls presenting with polyhydramnios and 72 without polyhydramnios. Amniotic fluid aldosterone was compared between the three groups. RESULTS: The median amniotic fluid aldosterone concentration in the Bartter syndrome group (90 pg/mL) was not different from that in the controls with polyhydramnios (90 pg/mL, P = 0.33) or without polyhydramnios (87 pg/mL, P = 0.41). CONCLUSION: Amniotic fluid aldosterone assay cannot be used for prenatal diagnosis of Bartter syndrome. © 2015 John Wiley & Sons, Ltd.

Impact of Including or Removing Nuchal Translucency Measurement on the Detection and False-Positive Rates of First-Trimester Down Syndrome Screening.

INTRODUCTION: First-trimester Down syndrome (DS) screening combining maternal age, serum markers (pregnancy-associated plasma protein-A and beta-human chorionic gonadotropin) and nuchal translucency (NT) gives an 85% detection rate for a 5% false-positive rate. These results largely depend on quality assessment of biochemical markers and of NT. In routine practice, despite an ultrasound quality control organization, NT images can be considered inadequate. The aim of the study was to evaluate the consequences for risk calculation when NT measurement is not taken into account. MATERIAL AND METHOD: Comparison of detection and false-positive rates of first-trimester DS screening (PerkinElmer, Turku, Finland), with and without NT, based on a retrospective study of 117,126 patients including 274 trisomy 21-affected fetuses. NT was measured by more than 3,000 certified sonographers. RESULTS: There was no significant difference in detection rates between the two strategies including or excluding NT measurement (86.7 vs. 81.8%). However, there was a significant difference in the false-positive rates (2.23 vs. 9.97%, p < 0.001). DISCUSSION: Sonographers should be aware that removing NT from combined first-trimester screening would result in a 5-fold increase in false-positive rate to maintain the expected detection rates. This should be an incentive for maintaining quality in NT measurement.

Amniotic fluid biochemistry in isolated polyhydramnios: a series of 464 cases.

OBJECTIVE: To report amniotic fluid biochemistry in a large series of 464 cases of isolated polyhydramnios in order to analyze both the outcome and the benefit of amniotic fluid biochemistry. METHODS: This retrospective cohort (2008-2012) included polyhydramnios cases for which amniotic fluid samples were sent to our laboratory for biochemical analysis (total protein, alpha-fetoprotein and gamma-glutamyl transpeptidase) so as to investigate the etiology. A Bartter index and an esophageal atresia index were defined. Final diagnoses were compared between groups to determine the association between these indices and the frequency and type of adverse outcomes. RESULTS: Among 464 cases of polyhydramnios considered isolated at ultrasound examination, severe fetal diseases were diagnosed in 136 (29.3%): 46 (9.9%) chromosomal anomalies, 28 (6%) Bartter syndrome, 23 (4.95%) other genetic syndromes, 22 (4.75%) swallowing disorders and 17 (3.7%) uro-nephrological disorders. Amniotic fluid biochemistry identified esophageal atresia with 66.6% (10/15) sensitivity and 100% specificity and Bartter syndrome with 85.7% (24/28) sensitivity and 84.2% specificity. CONCLUSION: Isolated polyhydramnios is associated with a high risk of severe fetal diseases. Molecular cytogenetics and amniotic fluid biochemistry are helpful tools.

First-trimester combined screening for trisomy 21 in women with renal disease.

OBJECTIVE: To evaluate the results of first-trimester combined screening for Down syndrome in women with chronic renal disease. METHOD: Fifty-five pregnant women with renal disease were compared with 110 patients matched for maternal age, maternal weight, smoking status, and gestational age. Maternal renal function was assayed at the time of the combined screening, and renal insufficiency was defined by serum creatinine >90 µmol/L and renal clearance <80 mL/min. We defined three groups: kidney disease and normal renal function (group 1), kidney disease and renal insufficiency (group 2), and a control group (group 3). The values of nuchal translucency, pregnancy-associated plasma protein A, human ß-chorionic gonadotrophin (hCGß), and false-positive rates for Down syndrome screening were compared. RESULTS: There were 39 (71%) and 16 (29%) cases in groups 1 and 2, respectively. Nuchal translucency and multiple of the median (MoM) pregnancy-associated plasma protein A were similar in the three groups. However, MoM hCGß levels were higher in group 2 than in groups 1 and 3 (5.37 vs 1.1 vs 0.98 MoM, p = 0.0001). The resulting screen-positive rate was also higher in group 2 than in groups 1 and 3 (43.7% vs 10.2% vs 5.5%, p = 0.0001). CONCLUSION: Trisomy 21 first-trimester screening using hCGß is not suitable in the case of maternal renal failure. © 2014 John Wiley & Sons, Ltd.

Performance of prenatal diagnosis in esophageal atresia.

OBJECTIVE: The aim of this study was to evaluate the performance of prenatal diagnosis of esophageal atresia (EA) and its associated abnormalities. METHODS: We conducted a retrospective study from a pediatric database of EA managed postnatally in a single center. Prenatal data included ultrasound and magnetic resonance imaging parameters including amniotic fluid (AF) volume, stomach visualization, AF biochemistry, and associated malformations. Postnatal data included type of EA, mortality, and postnatal diagnosis of associated malformations. RESULTS: One hundred twenty-two cases were included. The diagnosis was suspected prenatally in 39/122 (32%) cases. Polyhydramnios was noted in 64/122 (52.4%), and the stomach was not visualized or small in 39 (32%). There was 14 (11.5%), 2 (1.6%), 101 (82.8%), 5 (4.1%), and 0 (0%) types I, II, III, IV, and V, respectively. EA was suspected prenatally in 12/14 (85.7%) in type I and in 27/108 (25%) in cases with tracheoesophageal fistula (II + III + IV + V). Magnetic resonance imaging was performed in 28 cases, which confirmed EA in 19/28 (sensitivity 67.8%). AF biochemistry was performed in 17 cases, which confirmed EA in 15/17 (sensitivity 88.2%) cases. Of the 69 syndromic associations, 41/69 (59.4%) cases were detected prenatally. Associated malformation was a strong predictor of postnatal death [19/69 vs 3/53, odds ratio 6.33 (1.76; 22.75), p < 0.01]. CONCLUSION: Prenatal diagnosis of EA remains challenging. MRI and AF biochemistry may prove useful in the diagnosis of EA. Prenatal ultrasound and MRI examination should also focus on associated anomalies. © 2015 John Wiley & Sons, Ltd.

Down syndrome maternal serum marker screening after 18 weeks of gestation: a countrywide study.

OBJECTIVE: The objective of the study was to evaluate the efficacy of maternal serum markers in detecting Down syndrome after 18 weeks of gestation in women who book late for maternity care in a large national retrospective study. STUDY DESIGN: During the period 2007-2012, 27,648 women, regardless of maternal age (17.4% were 35 years old and over), were included in a late Down syndrome screening program (18(+0) to 35(+6) weeks) using the maternal serum markers alpha-fetoprotein and human chorionic gonadotrophin-beta. Samples were assayed in a single laboratory. A dataset of median markers previously established in our laboratory was used for risk calculation. The control group consisted of 27,648 women (14(+0) to 17(+6) weeks) randomly selected from the routine database. RESULTS: When the later screening group was compared with the standard second-trimester control group, the median multiples of medians (1.01 vs 0.98 for alpha-fetoprotein, 1.03 vs 0.98 for human chorionic gonadotrophin-beta), median risks (1 of 2414 vs 1 of 2720), false-positive rates (11.1% vs 11.6%), and trisomy 21 detection rates (83.3% vs 85.7%) did not differ significantly. CONCLUSION: Late Down syndrome maternal serum screening is feasible with a good sensitivity/specificity compromise throughout gestation and is of clinical value in late-booking women.

Management strategy in pregnancies with elevated second-trimester maternal serum alpha-fetoprotein based on a second assay.

OBJECTIVE: To assess maternal-fetal outcomes in pregnancies associated with persistently elevated second-trimester maternal serum alpha-fetoprotein. STUDY DESIGN: A retrospective cohort study in 658 patients with maternal serum alpha-fetoprotein ≥2.5 multiple of median, performed at routine Down syndrome screening. Maternal serum alpha-fetoprotein was assayed a second time in 341 of them. Outcomes were recorded in all cases. RESULTS: The group with unexplained maternal serum alpha-fetoprotein persistently ≥2.5 multiple of median was associated with more pregnancy complications 37 of 92 (40.2%) as fetal death, preeclampsia, intrauterine growth restriction, and congenital nephrotic syndrome, compared with the group with maternal serum alpha-fetoprotein that returned to a normal level 37 of 226 (16.4%) (P < .001). CONCLUSION: When maternal serum alpha-fetoprotein returns to a normal level on a second assay, the risk of adverse outcome significantly decreases, but these pregnancies are still at risk of complications and therefore need close surveillance. Repeat maternal serum alpha-fetoprotein assay allows identification of patients who should be offered amniocentesis to evaluate the risk of nephrotic syndrome and epidermolysis bullosa. Alpha-fetoprotein should be monitored in pregnancies associated with unexplained high maternal serum alpha-fetoprotein. A management strategy based on ultrasound examination, second maternal serum alpha-fetoprotein assay and amniocentesis is proposed to improve prenatal counseling and management of such pregnancies. However, a prospective study remains necessary to evaluate it.

Specific biochemical amniotic fluid pattern of fetal isolated esophageal atresia.

BACKGROUND: Perinatal care of esophageal atresia (EA) may be improved by prenatal diagnosis. Ultrasound findings (polyhydramnios and/or nonvisualization of fetal stomach) lead to a detection rate of ~50%. An amniotic fluid (AF) biochemical pattern characterized by high total protein, γ-glutamyl transpeptidase (GGTP), and normal l-leucine-aminopeptidase (AMP) leads to a 100% detection rate. The aim of this study was to explain this specific pattern. METHODS: On the basis of enzyme activities assay, the following four objectives were sought: (i) comparing AF markers between EA and other digestive tract atresias, (ii) determining local GGTP synthesis in the esophagus (immunohistobiochemistry), (iii) determining the presence of a specific AF-AMP activity inhibitor, and (iv) comparing AF-AMP and AF-GGTP half-lives. RESULTS: The AF-EA pattern was similar to that observed in upper duodenal atresia (above the Oddi sphincter). No local synthesis of GGTP was observed in the esophagus. No AF-AMP activity inhibitor was found. AF-GGTP had a longer half-life than AF-AMP. CONCLUSION: Due to the swallowing anomaly observed in EA, GGTP and AMP values physiologically observed at 18 wk will decrease on the basis of the half-lives of markers, with a flat slope for GGTP and a sharp slope for AMP, therefore explaining the differences observed in the AF-EA pattern.

Outcome and etiologies of fetal megacystis according to the gestational age at diagnosis.

OBJECTIVE: To investigate the gestational age-specific outcomes and the different etiologies of megacystis diagnosed at screening ultrasound. METHODS: A retrospective single-center study was conducted between 1989 and 2009. We identified all consecutive cases of megacystis prenatally diagnosed during routine ultrasound screening. Outcome, final diagnosis, and renal function were recorded. RESULTS: Eighty-four patients were included. An isolated lower urinary tract obstruction was observed in 38/84 (45.2%), ureterovesical reflux in 9/84 (10.7%), an associated congenital abnormality in 32/84 (38.1%) and a normal bladder in 5/84 (6%). Increased gestational age at diagnosis was correlated with an increased rate of live born children (P < 0.01). No cases of megacystis diagnosed in the first trimester were born alive. When diagnosis of posterior urethral valves (PUV) was made in the third trimester, the ultimate survival rate was 11/13 (84.6%) compared with 3/12 (25%) for a diagnosis made in the second trimester (P = 0.02). CONCLUSION: Lower urinary tract obstruction is the main etiology of megacystis. Megacystis can also be part of more complex malformations. Outcome of megacystis detected in the first trimester is poor. PUV detected in the third trimester had a better overall survival rate than PUV detected in the second trimester.

Methylation metabolites in amniotic fluid depend on gestational age.

OBJECTIVE: Methylation metabolism is essential for fetus development. However, normative data for amniotic fluid (AF) concentrations of methylation metabolites at different gestational ages are lacking. We aimed to determine in AF reference values of 14 intermediates involved in methylation. METHODS: Two hundred sixty-eight AFs sampled between 14 and 39 weeks of gestation were retrospectively selected in our AF bank. Next, we measured methionine (Met)-cycle intermediates [S-adenosyl Met (AdoMet), S-adenosyl-l-homocysteine (AdoHcy), total Hcy, Met, and methyl malonic acid] and methyl donors and methyl acceptors (betaine, dimethylglycine, sarcosine, free and total choline, free and total ethanolamine, creatine, and guanidinoacetate) by liquid chromatography coupled with tandem mass spectrometry. RESULTS: Reference ranges according to gestational age were determined for each parameter. Strong correlations between metabolites directly connected in their metabolic pathway and between total Hcy and betaine were observed. CONCLUSION: Methionine, an essential amino acid required for protein synthesis, is the only parameter that dramatically decreases with gestational age. The AdoMet/AdoHcy ratio exponentially increases from 25 weeks of gestation, which could reflect increasing methylation capacities. The negative correlation between betaine and total Hcy together with a constant betaine to dimethylglycine ratio during gestation suggests that betaine may be used as a methyl donor during fetal life.

Fetal serum α-1 microglobulin for renal function assessment: comparison with ß2-microglobulin and cystatin C.

OBJECTIVE: To compare the prognostic value of fetal serum α1-microglobulin with that of ß2-microglobulin and cystatin C for postnatal renal function. METHOD: Retrospective study of α1-microglobulin, ß2-microglobulin, and cystatin C in fetal serum from 126 fetuses with congenital abnormalities of the kidney and urinary tract (73 and 53, respectively). Two groups were defined: group with normal renal function and group with renal failure. For live born infants, renal function was assessed on the basis of serum creatinine (cutoff 50 µmol/L) or glomerular filtration rate (cutoff 75 mL/min/1.73 m2) or both. In case of infant or fetal death, histological kidney lesions were considered. RESULTS: Significant differences (p < 0.001) were observed for the three markers between fetuses with good renal prognosis and those with renal failure (34.4 mg/L vs 67.6 mg/L for α1-microglobulin, respectively; 3.9 mg/L vs 7.35 mg/L, for ß2-microglobulin, respectively; and 1.67 mg/L vs 2.12 mg/L for cystatin C, respectively). Areas under receiver operator curves were used to compare the three markers, 0.96, 0.90, and 0.74 for ß2-microglobulin, α1-microglobulin, and cystatin C, respectively. CONCLUSION: Although α1-microglobulin is significantly different in fetuses with good renal prognosis and those with renal failure, overall, it is a less reliable prognostic marker than fetal serum ß2-microglobulin.

Biochemical amniotic fluid pattern for prenatal diagnosis of esophageal atresia.

Prenatal diagnosis of esophageal atresia (EA) may improve the outcome of affected neonates by allowing optimization of both prenatal and postnatal care. Prenatal sonographic detection is based on polyhydramnios and/or nonvisualization of the fetal stomach bubble, two signs with a large number of etiologies. We evaluated a biochemical approach to improving diagnostic efficiency. We compared amniotic fluid biochemical markers in 44 EA cases with 88 polyhydramnios and 88 nonpolyhydramnios controls. Both matched for GA with cases. Total proteins, alpha-fetoprotein (AFP), and digestive enzyme activities were assayed, including gamma-glutamyl transpeptidase (GGTP). We defined an EA index (AFP multiplied by GGTP). A significant difference (p < 0.0001) was observed for total protein, AFP, GGTP, and EA index between the EA group and each of the two control groups. No statistical difference was observed for any marker between the two most frequent EA subgroups (type I and type III) or between the two control groups. Using a cutoff of 3 for the EA index, 98% sensitivity and 100% specificity were observed for amniotic fluid prenatal diagnosis of EA, whatever the anatomical type. A large prospective series is required to confirm these results.

Down syndrome maternal serum screening in patients with renal disease.

OBJECTIVE: The objective of the study was to determine the value of maternal serum Down syndrome screening in patients affected by renal disease. STUDY DESIGN: A study group of 54 pregnant women with renal diseases defined before pregnancy, was compared with a control group of 108 patients matched for maternal age, maternal weight, smoking status, and gestational age. Maternal serum markers (free beta-human chorionic gonadotropin [hCG], total hCG, alpha-fetoprotein) expressed in multiple of median and maternal renal function markers (creatinine, beta2-microglobulin, alpha1-microglobulin) were assayed. RESULTS: The percentage of patients in the Down syndrome at-risk group (>1:250) using free beta-hCG was significantly higher (P < .02) in the renal disease group (48%) than in the control group (12%). No significant difference was observed for total hCG (25% vs 15%). CONCLUSION: Down syndrome screening using free beta-hCG is not applicable in patients with renal disease whatever the maternal serum creatinine and can be used with caution when total hCG is used.

Prenatal diagnosis of Bartter syndrome: amniotic fluid aldosterone.

Bartter syndrome is a severe inherited tubulopathy characterized at birth by salt wasting, severe polyuria, dehydration, growth retardation and secondary hyperaldosteronism. Prenatally, the disease is usually discovered following onset of severe polyhydramnios. We studied amniotic fluid aldosterone concentration in cases of Bartter syndrome and in control groups. Amniotic fluid aldosterone was assayed by radioimmunoassay. We undertook a retrospective case-control study based on 36 cases of postnatally diagnosed Bartter syndrome and 144 controls matched for gestational age. Two controls groups were defined: controls with polyhydramnios (n=72) and control without polyhydramnios (n=72). Amniotic fluid aldosterone was compared between the three groups. The median amniotic fluid aldosterone concentration in the Bartter syndrome group (90 pg/mL) did not differ significantly from that in the controls with polyhydramnios (90 pg/mL, p=0.33) or the controls without polyhydramnios (87 pg/mL, p=0.41). In conclusion, amniotic fluid aldosterone assay cannot be used for prenatal diagnosis of Bartter syndrome.

Fetal urine biochemistry in antenatal Bartter syndrome: a case report.

Bartter syndrome is a severe inherited tubulopathy responsible for renal salt wasting, and hence electrolyte disorders and dehydration. Prenatally, it is characterized by severe polyhydramnios caused by fetal polyuria. We studied for the first time fetal urine in a Bartter syndrome case and demonstrated that the tubulopathy is already present at 24 weeks of gestation.

Inflammation of choriodecidua induces tumor necrosis factor alpha-mediated apoptosis of human myometrial cells.

The present study investigated the ability of human choriodecidua to induce myometrial cell apoptosis through the secretion of tumor necrosis factor alpha (TNF). The secretion of TNF was evaluated in the culture supernatants of amnion and choriodecidua explants that were exposed to the bacterial endotoxin lipopolysaccharide (LPS) to mimic inflammation. The choriodecidua explants produced more TNF than the amnion explants in response to LPS stimulation, despite the fact that the choriodecidua had lower levels of TLR4 expression. Moreover, conditioned medium obtained from LPS-treated choriodecidua explants, but not that from amnion explants, decreased the number of viable cultured myometrial cells and induced cell apoptosis by inducing the overexpression of the proapoptotic protein BAX and by decreasing the expression of the anti-apoptotic protein BCL2. Neutralization of TNF in the choriodecidua-conditioned medium reversed this effect. Exogenous TNF mimicked LPS-treated choriodecidua-conditioned medium in that it induced myometrial cell apoptosis, reduced BCL2 expression, and increased BAX expression. Using neutralizing antibodies against both subtypes of TNF receptors, we found that only TNFRSF1A participates in TNF-induced myometrial cell apoptosis. Our in vitro model of LPS-induced inflammation of human fetal membrane explants suggests a mechanism by which TNF secreted by choriodecidua governs human myometrial cell apoptosis at the end of pregnancy. These data support the hypothesis that TNF participates in the complex network of signaling processes associated with uterine involution.