Fetal intra-abdominal bowel dilation in prediction of complex gastroschisis.

OBJECTIVE: To investigate intra-abdominal bowel dilation (IABD) in the prediction of complex gastroschisis. METHODS: This was a retrospective study of 174 singleton pregnancies with isolated fetal gastroschisis, resulting in live birth and with available ultrasound images from visits at both 20-22 and 30-32 weeks' gestation. IABD was measured as the greatest transverse diameter of the most dilated intra-abdominal bowel segment, by an operator blinded to postnatal outcome. The distribution of IABD measurements in those with complex and those with simple gastroschisis was determined and the best cut-off value to predict complex gastroschisis was selected using receiver-operating characteristics (ROC) curves. The area under the ROC curve (AUC), detection rate (DR), false-positive rate (FPR), positive predictive value (PPV) and negative predictive value (NPV) were determined. RESULTS: The study population included 39 (22.4%) cases of complex and 135 (77.6%) cases of simple gastroschisis. In the prediction of complex gastroschisis, the AUC at 20-22 weeks' gestation was 0.742 (95% CI, 0.628-0.856) and the respective value for 30-32 weeks was 0.820 (95% CI, 0.729-0.910). At the IABD cut-off of 7 mm at 20-22 weeks, DR, FPR, PPV and NPV for complex gastroschisis were 61.5%, 6.7%, 72.7% and 89.4%, respectively, and at IABD cut-off of 14 mm at 30-32 weeks, the respective values were 64.9%, 5.9%, 75.0% and 90.7%. CONCLUSION: Measurement of IABD at 20-22 or at 30-32 weeks' gestation is useful in the prediction of complex gastroschisis. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Vaginal progesterone decreases preterm birth and neonatal morbidity and mortality in women with a twin gestation and a short cervix: an updated meta-analysis of individual patient data.

OBJECTIVE: To assess the efficacy of vaginal progesterone for the prevention of preterm birth and neonatal morbidity and mortality in asymptomatic women with a twin gestation and a sonographic short cervix (cervical length ≤ 25 mm) in the mid-trimester. METHODS: This was an updated systematic review and meta-analysis of individual patient data (IPD) from randomized controlled trials comparing vaginal progesterone with placebo/no treatment in women with a twin gestation and a mid-trimester sonographic cervical length ≤ 25 mm. MEDLINE, EMBASE, POPLINE, CINAHL and LILACS (all from inception to 31 December 2016), the Cochrane Central Register of Controlled Trials, Research Registers of ongoing trials, Google Scholar, conference proceedings and reference lists of identified studies were searched. The primary outcome measure was preterm birth < 33 weeks' gestation. Two reviewers independently selected studies, assessed the risk of bias and extracted the data. Pooled relative risks (RRs) with 95% confidence intervals (CI) were calculated. RESULTS: IPD were available for 303 women (159 assigned to vaginal progesterone and 144 assigned to placebo/no treatment) and their 606 fetuses/infants from six randomized controlled trials. One study, which included women with a cervical length between 20 and 25 mm, provided 74% of the total sample size of the IPD meta-analysis. Vaginal progesterone, compared with placebo/no treatment, was associated with a statistically significant reduction in the risk of preterm birth < 33 weeks' gestation (31.4% vs 43.1%; RR, 0.69 (95% CI, 0.51-0.93); moderate-quality evidence). Moreover, vaginal progesterone administration was associated with a significant decrease in the risk of preterm birth < 35, < 34, < 32 and < 30 weeks' gestation (RRs ranging from 0.47 to 0.83), neonatal death (RR, 0.53 (95% CI, 0.35-0.81)), respiratory distress syndrome (RR, 0.70 (95% CI, 0.56-0.89)), composite neonatal morbidity and mortality (RR, 0.61 (95% CI, 0.34-0.98)), use of mechanical ventilation (RR, 0.54 (95% CI, 0.36-0.81)) and birth weight < 1500 g (RR, 0.53 (95% CI, 0.35-0.80)) (all moderate-quality evidence). There were no significant differences in neurodevelopmental outcomes at 4-5 years of age between the vaginal progesterone and placebo groups. CONCLUSION: Administration of vaginal progesterone to asymptomatic women with a twin gestation and a sonographic short cervix in the mid-trimester reduces the risk of preterm birth occurring at < 30 to < 35 gestational weeks, neonatal mortality and some measures of neonatal morbidity, without any demonstrable deleterious effects on childhood neurodevelopment. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Longitudinal reference range for umbilical cord cross-sectional area in twin pregnancies at 18-32 weeks of gestation.

OBJECTIVES: The objectives of this study were to establish gestational age-specific reference ranges for cross-sectional area of the umbilical cord, and its components, in twin pregnancies and to compare them with previously reported singleton reference ranges. METHODS: This was a prospective longitudinal study involving uncomplicated dichorionic twin pregnancies. Sonographic measurements of the cross-sectional area of the umbilical cord, umbilical vein and arteries and Wharton's jelly were obtained in a plane adjacent to the fetal abdomen, every 3 weeks, between 18 and 32 weeks of gestations. Multilevel regression analysis was used to determine gestational age-specific reference ranges for each parameter, and these were plotted against singleton pregnancy references. RESULTS: Three hundred and thirty four ultrasound scans were performed in 44 twin pregnancies, between 18 and 32.9 weeks (mean: 3.8 ± 0.7 scans/pregnancy and mean interval between scans: 3.3 ± 0.9 weeks). All umbilical cord cross-sectional areas (total, vein, artery and Wharton's jelly) showed a significant increase with gestational age. Compared with singleton pregnancy ranges, mean values were considerably lower in twin pregnancies and resemble the lower limits observed in singletons. CONCLUSION: In twin pregnancies, cross-sectional area of the umbilical cord, and its components, increases between 18 and 32 weeks, and mean values are substantially lower compared with singleton pregnancies.

Placental transfer of IgG antibodies specific to Klebsiella and Pseudomonas LPS and to group B Streptococcus in twin pregnancies.

Group B Streptococcus (GBS), Klebsiella spp. and Pseudomonas spp. are important aetiological agents of neonatal infections in Brazil. There is a lack of data in the literature regarding the specific transport of immunoglobulin G (IgG) against these pathogens in multiple pregnancies. Maternal (n = 55) and umbilical cord (n = 110) blood samples were prospectively collected at birth from 55 twin pregnancies. The factors associated with cord levels and transfer ratios of IgG against GBS, Klebsiella and Pseudomonas were examined. The IgG umbilical cord serum levels specific to GBS, Klebsiella LPS and Pseudomonas LPS were significantly associated with maternal-specific IgG concentrations and the presence of diabetes. The anti-Klebsiella IgG cord serum concentrations were also related to birthweight and the presence of hypertension. The transfer ratios against GBS and Pseudomonas LPS were associated with maternal-specific IgG concentrations. The transfer ratios for GBS and Pseudomonas LPS were associated with gestational age at delivery and the presence of diabetes, respectively. None of the examined parameters were related to Klebsiella LPS transfer ratios. We conclude that in twin pregnancies, specific maternal IgG serum concentrations and diabetes were the parameters associated with umbilical cord serum IgG concentrations reactive with the three pathogens investigated. All the other parameters investigated showed different associations with neonatal-specific IgG levels according to the antigen studied. There was no uniformity of the investigated parameters regarding association with placental IgG transfer ratios against the GBS, Pseudomonas LPS and Klebsiella LPS.

Conjoined twins pregnancies: experience with 36 cases from a single center.

OBJECTIVE: To review a single center's experience in the management of twin pregnancies with conjoined fetuses. METHODS: Retrospective study describing prenatal findings, delivery details, surgical treatment and perinatal outcome. RESULTS: The study included 36 twin pregnancies with conjoined twins seen over a period of 12 years in a single tertiary hospital: 69.4% were thoracopagus, 13.9% parapagus, 8.3% omphaloischiopagus 5.6% omphalopagus and 2.8% cephalopagus. Cardiac defects were present in 91.6% of twin pairs and associated malformations were present in 61.8% of the cases: limb abnormalities in 36.1%, abdominal wall defects in 25.0%, cleft lip and/or palate in 13.9% and congenital diaphragmatic hernia in 5.5%. Surgical separation was considered not feasible and prognosis lethal in 30 (83.3%) cases. Termination of pregnancy was performed in 12 pregnancies of poor prognosis. Cesarean section was performed in all remaining cases. Five sets of twins underwent surgical separation and six children survived. Overall survival in our series was 8.3% and, among the livebirths, 13.6%. CONCLUSION: Conjoined twin pregnancies should be referred to tertiary centers for detailed fetal anomaly and echocardiographic assessment to evaluate prognosis and determine the possibility of postnatal surgical separation.

Sonographic markers of exencephaly below 10 weeks' gestation.

We report two cases of exencephaly diagnosed by transvaginal ultrasonography at 8 weeks 4 days and at 9 weeks 3 days of gestation. Both cases presented an irregular cephalic pole, and, in the case seen at 8 weeks 4 days, brain vesicles were also absent, whereas in the case seen at 9 weeks 3 days, the midline echo was indistinguishable with disorganized choroid plexuses. In both cases, anencephaly was evident at 11 and 12 weeks' gestation and the postmortem confirmed the diagnosis.

Ductus venosus blood flow assessment at 11 to 14 weeks of gestation and fetal outcome.

OBJECTIVE: To evaluate the association between abnormal ductus venosus (DV) at 11-14 weeks' gestation and chromosomal abnormalities, structural defects and fetal outcome. METHODS: DV flow-velocity waveform (DV-FVW) and nuchal translucency thickness (NT) were prospectively evaluated in 1217 singleton pregnancies. RESULTS: The DV-FVW was abnormal in 84 fetuses, NT was above the 95th centile in 160 fetuses and both markers were observed in 41 fetuses. Chromosomal defects were diagnosed in 22 fetuses. The sensitivity, specificity and positive and negative predictive values for an abnormal karyotype were 86.4%, 86.9%, 11.9% and 99.7%, respectively, for an increased NT. These values were 68.2%, 96.9%, 31.3% and 99.3%, respectively, for DV-FVW abnormalities and 68.2%, 97.6%, 36.6% and 99.3%, respectively, when both markers were found simultaneously. Regarding structural defects, these values were 43.8%, 92.9%, 8.3% and 99.1% for an abnormal NT, 25.0%, 92.6%, 4.8% and 98.8% for DV-FVW abnormalities and 25.0%, 97.9%, 15.4% and 98.9% for both together. Considering those cases of unexplained fetal demise, the values were 44.4%, 85.9%, 5.0% and 98.9% for NT abnormalities, 22.2%, 92.6%, 4.8% and 98.6% for an abnormal DV-FVW and 22.2%, 98%, 15.4% and 98.7% for both. In cases with increased NT, the percentage of live births with normal karyotype and no major fetal structural defects decreased from 93.8% in normal DV-FVW fetuses to 77.3% in abnormal ones. CONCLUSION: DV assessment at 11-14 weeks' gestation is useful in screening for fetal chromosomal abnormalities and may help to reduce the false-positive rate when combined with NT measurement. Abnormal DV-FVW is also associated with an increase in adverse perinatal outcome in fetuses with enlarged NT. However, the value of DV-FVW assessment in cases with normal NT is unclear.

Structural and functional cardiac abnormalities identified prior to 16 weeks' gestation in fetuses with increased nuchal translucency.

OBJECTIVE: To determine the accuracy and practicality of fetal echocardiography in the identification of structural and functional cardiac abnormalities prior to 16 weeks' gestation in fetuses with increased nuchal translucency thickness (NT). METHODS: Between January 1996 and June 2002 early fetal echocardiography using the transvaginal route was performed at 12-16 weeks' gestation on 275 fetuses with increased NT. The abnormal cardiac findings were classified as either structural (congenital heart defects) or functional, defined as transient phenomena which might later disappear, such as isolated tricuspid regurgitation and an enlarged ascending aorta. The abnormal findings were related to pregnancy outcome, including autopsy results, karyotyping results, and late fetal and neonatal echocardiography. RESULTS: Cardiac abnormalities were present in 61 fetuses overall (22.2%); including structural cardiac defects in 37 fetuses (13.5%) and functional abnormalities in 24 fetuses (8.7%). Structural cardiac abnormalities were associated with abnormal karyotype in 24 fetuses and normal karyotype in 13 fetuses. Of the 24 fetuses with functional cardiac abnormalities, 2 (8.3%) had isolated tricuspid regurgitation and 22 (91.7%) had enlarged ascending aorta. Abnormal karyotype was present in this group in 4 cases (16.7%). CONCLUSION: Increased NT can be used to define a high-risk group that should receive specialized early fetal echocardiography. This is a reliable technique with great potential for the diagnosis of both structural and functional cardiac abnormalities.

Cervical length at 11-14 weeks' and 22-24 weeks' gestation evaluated by transvaginal sonography, and gestational age at delivery.

OBJECTIVE: To compare cervical length measurements obtained at 11 to 14 weeks and 22 to 24 weeks of gestation in an unselected group of pregnant women and to correlate the measurements with time of delivery. METHODS: This was a prospective study involving 529 pregnant women attending for routine antenatal care who underwent transvaginal scans at 11-14 weeks and 22-24 weeks for evaluation of cervical length. The mean cervical length was calculated at both stages of gestation and lengths were compared between groups which delivered at term or prematurely, this being defined as delivery before 37 completed weeks of gestation. RESULTS: The mean cervical lengths at 11-14 and 22-24 weeks were, respectively, 42.4 mm and 38.6 mm. Cervical length at 11-14 weeks was not significantly different between the groups which delivered at term (42.7 mm) and preterm (40.6 mm). However, at the 22-24-week evaluation, cervical length was significantly shorter in the group which had a preterm delivery than in that which had a term delivery (26.7 mm and 39.3 mm, respectively; P = 0.0001). In the group of women with a previous history of one or more preterm deliveries, there was a greater shortening in cervical length from the first to the second evaluation than there was in the group of women with no previous history of preterm delivery. This shortening was also more pronounced in the group which delivered prematurely (from 40.6 mm to 26.7 mm) than in that which delivered at term (from 42.7 mm to 39.3 mm). CONCLUSION: There is a spontaneous shortening in the pregnant cervix from the first to the second trimester of pregnancy. The shortening is more rapid in pregnant women who deliver prematurely and who have a history of previous preterm delivery.

Transvaginal ultrasonography in predicting placenta previa at delivery: a longitudinal study.

OBJECTIVES: To determine the extent of overlapping of the internal cervical os by the lower placental edge at 11-14 weeks' gestation which best predicts placenta previa at term. PATIENTS AND METHODS: This was a prospective study initially involving 381 singleton pregnancies with a live fetus at 11-14 weeks attending for routine antenatal care. The distance between the lower placental edge and the internal cervical os was longitudinally evaluated by transvaginal ultrasound examination at 11-14 weeks', 20-24 weeks', and 30-34 weeks' gestation. The first 203 cases were selected at random (first phase) and after this period only cases with the lower placental edge reaching and/or overlapping the internal cervical os were followed up (n = 170, second phase). Thus a total of 373 cases were analyzed, 351 of whom were examined in all three trimesters. Multiple regression analysis was used to estimate the probability of predicting placenta previa at term using the overlap of the lower placental edge over the internal cervical os in the first trimester of pregnancy. RESULTS: A change in the relative position of the placenta (placental migration) was observed in all 351 cases examined in the three trimesters of pregnancy. In the general population, represented by the 203 cases (first phase), the incidence of placenta previa at 11-14 weeks' gestation was 42.3% (86/203), at 20-24 weeks' 3.9% (8/203) and at term 1.9% (4/203). A total of 18 cases of placenta previa and 17 cases of marginal placenta were observed at term. It was estimated that when the lower placental edge overlaps the internal cervical os by 23 mm at 11-14 weeks the probability of placenta previa at term is 8% with a sensitivity of 83.3% and specificity of 86.1%. CONCLUSION: The present study establishes the probability of placenta previa at term depending on the relationship of the lower placental edge to the internal cervical os at 11-14 weeks.

Effect of maternal position on cervical length measurement in twin pregnancies.

OBJECTIVE: To compare cervical length measurements in twin pregnancies obtained from patients in the recumbent and standing positions. METHODS: Fifty women with uncomplicated twin pregnancies underwent monthly transvaginal ultrasound examinations for cervical length measurement in the recumbent and standing positions. The correlation between cervical length measurements obtained in the recumbent and standing positions, and between these measurements and gestational age, were examined. The significance of the differences between measurements obtained in the recumbent and standing positions was also analyzed. RESULTS: Based on data obtained at the first ultrasound examination, there was a significant correlation between cervical length measurements in the recumbent and standing positions (r = 0.77; t = 8.25; P < 0.0001) and both measurements showed a significant inverse correlation with gestational age (recumbent position: r = -0.60, P < 0.0001; standing position: r = -0.46; P = 0.0008). The mean of the differences (standing - recumbent) was -1.8 mm (95% confidence interval = -3.7-0.04; t = -1.96; P = 0.06) and the mean of percentage differences ((standing - recumbent)/recumbent x 100) was -2.9% (95% confidence interval = -8.6-2.7; t = -1.04; P = 0.3). When the data obtained at all examinations were examined by multiple regression analysis, cervical length measurement in the recumbent position was the only parameter that correlated significantly with the percentage difference between cervical length measurements (P < 0.0001). CONCLUSIONS: Cervical length in twin pregnancies decreases with gestation and there is a good correlation between measurements obtained from women in the recumbent and standing positions. No significant changes in cervical length were observed comparing measurements obtained in the two maternal positions.

Detection of fetal structural abnormalities at the 11-14 week ultrasound scan.

The aim of this study was to evaluate the detection of fetal structural abnormalities by the 11-14 week scan. 2853 pregnant women were submitted to a routine ultrasound scan between the 11th and 14th week and the fetal skull, brain, spine, abdominal wall, limbs, stomach and bladder were examined. Following the scans the patients were examined in the second or third trimester of pregnancy. An isolated increased nuchal translucency was not considered an abnormality. However, these patients had an early echocardiography assessment. Fetal structural abnormalities were classified as major or minor and of early or late onset. A total of 130 (4.6%) defects were identified and 29 (22.3%) of these were diagnosed at the 11-14 week scan, including nine cardiac defects associated with increased nuchal translucency. The antenatal ultrasound detection rate was 71.5%, and 31.2% were detected in the first-trimester assessment. 78.8% of the major defects were diagnosed by the prenatal scan and 37.8% by the 11-14 week scan. Fetal structural abnormalities at the 11-14 week scan were detected in approximately 22.3% of the cases, therefore, a second-trimester anomaly scan is important in routine antenatal care to increase the prenatal detection of fetal defects.

Trisomy 10: ultrasound features and natural history after first trimester diagnosis.

We report on the ultrasound features and natural history of trisomy 10. At 12 weeks' gestation in a routine scan examination, the fetus presented with increased nuchal translucency thickness, mild skin oedema, bilateral pleural effusion, marked micrognathia, cardiomegaly, unilateral talipes and reversed A-wave in the ductus venosus blood flow. Karyotyping on chorionic villus sampling (CVS) led to the diagnosis of trisomy 10, which was confirmed by fetal blood sampling at 22 weeks' gestation. As the parents opted to continue with the pregnancy, the natural history and following ultrasound features are described. This is the third case of trisomy 10 in the literature reporting on the physical features. The most frequent ultrasound findings presented in trisomy 10 are increased nuchal translucency, micrognathia, renal agenesis, facial cleft, limbabnormalities, cardiac defects and early severe growth retardation.

First-trimester screening for chromosomal abnormalities by fetal nuchal translucency in a Brazilian population.

OBJECTIVES: To examine the detection rate of chromosomal abnormalities using nuchal translucency (NT) thickness in a Brazilian population. METHODS: This was a prospective study of 2996 singleton pregnancies with a live fetus at 10-14 weeks of gestation attending for routine antenatal care in a teaching hospital in Brazil. Fetal crown-rump length (CRL) and NT thickness were measured and the risks for trisomy 21 were calculated by a combination of maternal age and fetal NT with the use of software provided by The Fetal Medicine Foundation. Sensitivity and positive predictive values for different risk cut-offs were calculated. RESULTS: Chromosomal defects were diagnosed in 22 cases, including 10 cases of trisomy 21. The estimated risk based on maternal age and fetal NT was 1 in 300 or greater in 222 (7.4%) cases and these included nine of 10 (90.0%) pregnancies with trisomy 21 and nine of 12 (75.0%) pregnancies with other chromosomal defects. The NT was above the 95th centile in 5.8% of cases and this group included 70% of the trisomy 21 cases. CONCLUSION: A combination of maternal age and fetal NT provides an effective method of screening for chromosomal defects. The performance of the test in a Brazilian population is similar to that in Britain.

Placental mRNA expression of alpha and beta human chorionic gonadotrophin in early trisomy 18 pregnancies.

The placental expression of human chorionic gonadotrophin (HCG) I- and beta-subunits was investigated in eight pregnancies presenting with trisomy 18 and in 30 normal pregnancies at 11-15 weeks gestation. In the control group, the median densitometric scores of placental beta-HCG and I-HCG mRNA were 1.23 and 1.74 respectively. In the trisomy 18 group the median beta-HCG mRNA was significantly lower (0.16, Z = 2.29, P < 0.05) but alpha-HCG [0.60, Z = 1.75, P = 0.08) was not significantly different from normal. These findings suggest that in trisomy 18 the decrease in maternal serum concentration of HCG subunits results from an impairment in the transcription of the corresponding gene which affects the beta subunit to a greater extent than the I subunit.

Cardiac gene expression of atrial natriuretic peptide and brain natriuretic peptide in trisomic fetuses.

OBJECTIVE: To investigate whether the increased nuchal translucency of trisomic fetuses is the consequence of heart failure by examining cardiac expression of atrial natriuretic peptide and brain natriuretic peptide genes. METHODS: Cardiac atrial natriuretic peptide and brain natriuretic peptide messenger RNA (mRNA) levels were measured in fetal hearts from 15 pregnancies affected by trisomy 21 or 18 at 12-16 weeks' gestation and from 30 normal controls at 10-20 weeks. RESULTS: In normal fetuses, mRNA levels of atrial natriuretic peptide decreased, but levels of brain natriuretic peptide did not change significantly with gestation. In trisomic fetuses, mRNA levels of both atrial natriuretic peptide and brain natriuretic peptide were significantly higher than in gestational age-matched normal controls. CONCLUSION: These data demonstrate that atrial natriuretic peptide and brain natriuretic peptide genes are transcribed prenatally, and the findings in trisomic fetuses suggest that the increased translucency of trisomic fetuses may be the consequence of heart failure.