Prenatal Brain MR Imaging: Reference Linear Biometric Centiles between 20 and 24 Gestational Weeks

BACKGROUND AND PURPOSE

Evaluation of biometry is a fundamental step in prenatal brain MR imaging. While different studies have reported reference centiles for MR imaging biometric data of fetuses in the late second and third trimesters of gestation, no one has reported them in fetuses in the early second trimester. We report centiles of normal MR imaging linear biometric data of a large cohort of fetal brains within 24 weeks of gestation.

MATERIALS AND METHODS

From the data bases of 2 referral centers of fetal medicine, accounting for 3850 examinations, we retrospectively collected 169 prenatal brain MR imaging examinations of singleton pregnancies, between 20 and 24 weeks of gestational age, with normal brain anatomy at MR imaging and normal postnatal neurologic development. To trace the reference centiles, we used the CG-LMS method.

RESULTS

Reference biometric centiles for the developing structures of the cerebrum, cerebellum, brain stem, and theca were obtained. The overall interassessor agreement was adequate for all measurements.

CONCLUSIONS

Reference biometric centiles of the brain structures in fetuses between 20 and 24 weeks of gestational age may be a reliable tool in assessing fetal brain development.

Diagnostic Value of Prenatal MR Imaging in the Detection of Brain Malformations in Fetuses before the 26th Week of Gestational Age

BACKGROUND AND PURPOSE

In several countries, laws and regulations allow abortion for medical reasons within 24-25 weeks of gestational age. We investigated the diagnostic value of prenatal MR imaging for brain malformations within 25 weeks of gestational age.

MATERIALS AND METHODS

We retrospectively included fetuses within 25 weeks of gestational age who had undergone both prenatal and postnatal MR imaging of the brain between 2002 and 2014. Two senior pediatric neuroradiologists evaluated prenatal MR imaging examinations blinded to postnatal MR imaging findings. With postnatal MR imaging used as the reference standard, we calculated the sensitivity, specificity, positive predictive value, and negative predictive value of the prenatal MR imaging in detecting brain malformations.

RESULTS

One-hundred nine fetuses (median gestational age at prenatal MR imaging: 22 weeks; range, 21-25 weeks) were included in this study. According to the reference standard, 111 malformations were detected. Prenatal MR imaging failed to detect correctly 11 of the 111 malformations: 3 midline malformations, 5 disorders of cortical development, 2 posterior fossa anomalies, and 1 vascular malformation. Prenatal MR imaging misdiagnosed 3 findings as pathologic in the posterior fossa.

CONCLUSIONS

The diagnostic value of prenatal MR imaging between 21 and 25 weeks' gestational age is very high, with limitations of sensitivity regarding the detection of disorders of cortical development.

Cesarean section plus delayed cord clamping approach in the perinatal management of congenital high airway obstruction syndrome (CHAOS): a case report

In this case, we describe a newborn with prenatal diagnosis of congenital high airway obstruction syndrome (CHAOS), successfully managed with a cesarean section with delayed cord clamping 180 seconds. In case of prenatal diagnosis of CHAOS, prompt airway intervention at delivery allows survival of this otherwise fatal condition. Ex utero intrapartum treatment (EXIT) is considered the elective procedure to secure the fetal airway before the baby is completely separated from the maternal circulation. In cases where the EXIT procedure is not possible for maternal reasons (Ballantyne's syndrome), delayed cord clamping may serve as an alternative method to manage CHAOS.

Outcome of congenital diaphragmatic hernia: analysis of implicated factors

AIM

Congenital diaphragmatic hernia remains a significant challenge for neonatologists and pediatric surgeons. Over the last years, new therapeutic approaches, as high-frequency oscillatory ventilation, inhaled nitric oxide, permissive hypercapnia, extracorporeal membrane oxygenation, have been used for the management of these newborns. We conducted a retrospective study of all infants who were managed for congenital diaphragmatic hernia in our NICU in order to identify possible clinical characteristics which were predictive for survival.

METHODS

We reviewed a single institution's experience with 42 consecutive neonates with congenital diaphragmatic hernia admitted to our NICU from 1993 to 2009.

RESULTS

Prenatal data and side of congenital diaphragmatic hernia were similar in survivors and no-survivors infants except for the lung-to-head ratio (LHR), which was higher and measured later in survivors than non-survivors. Multiple regression analysis showed that a gestational age ≥39 weeks, Apgar score at 5 min ≥7, FiO2<0.35, MAP<13 cmH2O, OI<10 and AaDO2 >282 before surgical repair, and the absence of persistent pulmonary hypoplasia were independent predictive factors of survival.

CONCLUSION

Our study suggests that the outcome of newborns with congenital diaphragmatic hernia still depends on the severity of lung hypoplasia, despite the different respiratory and therapeutical approaches.

Prognostic markers of symptomatic congenital human cytomegalovirus infection in fetal blood

OBJECTIVE

To identify fetal cord blood prognostic markers of symptomatic congenital human cytomegalovirus infection (HCMV).

DESIGN

Retrospective observational study.

SETTING

Fetal medicine unit in Milan and Medical virology unit in Pavia, Italy.

POPULATION

HCMV-infected and -uninfected fetuses of mothers with primary HCMV infection during the period 1995-2009.

METHODS

Overall, 94 blood samples from as many fetuses of 93 pregnant women experiencing primary HCMV infection were examined for multiple immunological, haematological and biochemical markers as well as virological markers. Congenital HCMV infection was diagnosed by detection of virus in amniotic fluid, and symptomatic/asymptomatic infections were determined by ultrasound scans, nuclear magnetic resonance imaging, histopathology or clinical examination at birth. Blood sample markers were retrospectively compared in symptomatic and asymptomatic fetuses with congenital infection.

MAIN OUTCOME MEASURES

A statistical analysis was performed to determine the value of each parameter in predicting outcome.

RESULTS

Univariate analysis showed that most nonviral and viral markers were significantly different in symptomatic (n = 16) compared with asymptomatic (n = 31) fetuses. Receiver operator characteristics analysis indicated that, with reference to an established cutoff for each marker, the best nonviral factors for differentiation of symptomatic from asymptomatic congenital infection were β(2) -microglobulin and platelet count, and the best virological markers were immunoglobulin M antibody and DNAaemia. β(2) -Microglobulin alone or the combination of these four markers reached the optimal diagnostic efficacy.

CONCLUSIONS

The determination of multiple markers in fetal blood, following virus detection in amniotic fluid samples, is predictive of perinatal outcome in fetuses with HCMV infection.

Prenatal MR imaging detection of deep medullary vein involvement in fetal brain damage

Looking for anomalies distributed in DMV territory, we reviewed 78 fetal MR imaging examinations performed at our institution reporting unequivocal cerebral clastic lesions. We selected 3 cases, all of which had severe cardiocirculatory failure and parenchymal frontoparietal WM hemorrhagic lesions with characteristic fan-shaped distribution. Brain edema and other signs of venous hypertension were also evident. Our data suggest that in utero transient venous hypertension may be responsible for the onset of atypical frontal-located PVL.

Conotruncal anomalies in prenatal life

This retrospective multicenter study represents an analysis of the intrauterine determinants of the prognosis for conotruncal anomalies. Data regarding reason for referral, presence of chromosomal or extracardiac anomalies, pregnancy and surgical outcome were recorded in 67 cases of conotruncal anomalies from three Italian referral units. Chromosomal aberrations effected 11 of the 60 (18.3%) fetuses in which a karyotype was available. Extra-cardiac malformations were present in 25/67 cases (37.3%). No chromosomal anomalies were present in fetuses with complete or corrected transposition of the great arteries. However, tetralogy of Fallot and double-outlet right ventricle were associated with chromosomal anomalies in 22% and 38% of cases, respectively, and with extracardiac anomalies in 45% and 46% of cases, respectively. Only 20 of the 67 (31%) cardiac malformations were associated with an abnormal four-chamber view. There were 28 (41.7%) terminations of pregnancy, six (8.9%) intrauterine deaths and 16 (23.8%) neonatal deaths. Seventeen neonates (25.3%) are currently alive, and 15 of these have undergone reparative surgery. The prognosis of conotruncal anomalies is poorer when the conditions is diagnosed in utero. This is mainly due to the frequent association with chromosomal and/or extracardiac anomalies, often leading to intrauterine or early neonatal death.

[The indications for the management of fetuses with choroid plexus cysts]

Choroid plexus cysts (CPC) in the fetus are still the subject of considerable debate in the literature. Because of their association with aneuploidy, and especially with trisomy 18, of which they are an ultrasonographic marker, the detection of fetal CPC now poses the problem of how these cases should be managed, since most occur in young women (there being no correlation between CPC and age), and since the incidence among the general population is fairly high (around 1%). With the aim of contributing further to the debate, a retrospective study was performed of all cases of fetal CPC diagnosed in our Centre between January 1984 and August 1994, together with a review of the relevant literature. There were 95 cases of fetal CPC with complete neonatal and necroptic data available. These cases included women recruited in the course of routine screening for congenital malformations carried out in our Centre at 14 and 21 weeks gestation, women referred to us from other Centres, and women recruited in the course of amniocentesis indicated for those aged over 35. In all cases in which fetal CPC was detected, a careful ultrasonographic examination was performed to exclude the presence of even the smallest morphologic anomaly. Whenever the fetus was found to have an anomaly karyotyping was done. If the CPC was not associated with any morphologic anomaly, karyotyping was proposed only to those women at risk of aneuploidy because of their age. There were 11 cases of trisomy 18, all of which presented morphologic anomalies associated with CPC. Some of these anomalies where "minor", however, and therefore difficult to assess even when a careful ultrasonographic examination was performed by an experienced operator (Intra ventricular septal defect, single umbilical artery). In 2 cases, CPC was associated with trisomy 21. Both women were aged over 35. All the other cases of CPC not associated with morphologic anomaly were normal on postnatal examination. From a meta-analysis of the literature, two distinct management protocols emerge for the problem of "isolated CPC detected at ultrasonographic examination". One group of authors recommends karyotyping for all women with fetal CPC, considering the presence of CPC in itself a risk factor for aneuploidy. The second group, to which we ourselves belong, believes it is sufficient to perform a careful ultrasonographic examination so as to exclude the presence of other morphologic anomalies associated with the CPC. Karyotyping should be proposed only to women at risk of aneuploidy because of their age (> 35). A review of the biggest series reported in the literature shows that, of a total of 1670 fetuses with CPC, 94 were trisomy 18. None of the cases of CPC "in isolation" emerged as being associated with this aneuploidy. However, numerous cases of trisomy 18 have been described in which CPC is associated with "minor" morphologic anomalies in the fetus which may be difficult to detect. It is therefore essential to perform a careful ultrasonographic examination in all cases of CPC, preferably in a Centre with specialist knowledge of ultrasonography. If this option is not available, then karyotyping of all women with fetal CPC is clearly advisable.

[Seasonal incidence of extrauterine pregnancy]

Ectopic pregnancy (EP) is becoming a more and more frequent problem in many developed countries, but the cause of such increase is not fully understood. Improved diagnosis certainly explains part of it, but also the changing lifestyle and sexual habits might play an important role. During the years 1990-1993, 56 women were admitted into the Divisione di Ostetricia e Ginecologia of the Istituto per l'Infanzia of Trieste because of EP diagnosed on the basis of clinical history and signs, transvaginal echography and serum HCG levels. 33 of them underwent surgical operation for the presence of severe abdominal pain, hemoperitoneum greater than 50 cc, and increases HCG level. The other 23 women were treated conservatively. Taking into account the approximate date of conception both for ectopic and other pregnancies, the monthly incidence of EP was computed and showed a statistically significant peak during the summer period (14.4%) compared to the other periods (6%). The increased frequency of EP among pregnancies started during the warmer months is interesting not only as a descriptive result, but also because it may contribute to a better understanding of the conditions under which the ectopic development of the fertilized ovum may take place.

Endometrial assessment by transvaginal sonography and histological findings after D & C in women with postmenopausal bleeding

A total of 149 women with postmenopausal bleeding underwent transvaginal sonography, hysteroscopy and dilatation and curettage in order to study the diagnostic accuracy of several ultrasound parameters in assessing endometrial pathology and to determine the most sensitive cut-off value of endometrial thickness for the exclusion of endometrial lesions. In distinguishing pathological from normal endometrium, transvaginal sonography showed a sensitivity of 69.3%, specificity of 82.7%, positive predictive value of 74.1% and negative predictive value of 72.1%. In detecting premalignant and malignant endometrial pathology, transvaginal sonography showed a sensitivity, specificity, positive predictive value and negative predictive value of 55%, 96.1%, 68.7% and 93.2%, respectively. Considering endometrial thickness as a single parameter, the most sensitive cut-off for defining normality was 4 mm; nevertheless, in the group of patients that had an endometrial thickness less than 4 mm, there was one case of malignancy (sensitivity, 95.2%; specificity, 49.4%; positive predictive value, 57.3%; and negative predictive value, 93.5%). Transvaginal sonography combined evaluation (morphology, thickness and color Doppler) showed a poor diagnostic accuracy in detecting endometrial pathology and in differentiating between endometrial benign lesions, endometrial polyps and adenocarcinoma in women with postmenopausal bleeding. Endometrial thickness evaluated with transvaginal sonography was preferable but not sensitive enough to exclude endometrial pathology.

[The diagnostic capacities of transvaginal echography and hysteroscopy in the characterization of endometrial pathology]

The diagnostic accuracy of transvaginal sonography (TVS) and hysteroscopy in the assessment of endometrial pathology was studied comparing retrospectively both methods with the results of histologic findings after dilatation and curettage (D&C) performed in the last four years on 467 patients, 155 of whom were in postmenopause. Endometrial thickness, tissue texture, myometrial invasion and haemodynamic characteristics were studied with TVS. Uterine cavity, endometrial patterns and superficial vascularization were evaluated by hysteroscopy. For the purpose of this study all histologic findings were subdivided to a) normal (206 cases); b) benign lesions (240 cases); c) atypical hyperplasia or adenocarcinoma (21 cases). In our experience hysteroscopy was superior to TVS in detecting endometrial pathology. Both techniques were more sensitive in detecting premalignant and malignant lesions. Considering endometrial thickness evaluated with TVS as a single parameter in patients in postmenopause, we found that the most sensitive cut-off for defining normality was 3 mm; nevertheless, in the group of patients that had an endometrial thickness equal to or less than 3 mm there were 2 cases of malignancy. Therefore, neither TVS nor hysteroscopy are sufficiently reliable to replace curettage in the diagnosis of endometrial pathology.