Termination of pregnancy due to fetal central nervous system abnormalities performed after 24 weeks' gestation: survey of 57 fetuses from a single medical center

Parental magnetic resonance imaging for the evaluation of fetuses with brain anomalies

AIM

To evaluate the role of parental magnetic resonance imaging (MRI) in assessing fetuses with suspected brain anomalies and its use in prenatal counselling.

METHOD

A retrospective, multicentre chart review was conducted on fetuses who underwent brain MRI because of suspected brain abnormalities between January 2008 and December 2022, with one or both parents who underwent brain MRI (MRI-Trio) as part of prenatal counselling. Clinical and demographic data were collected, including fetal and parental MRI findings, prenatal counselling outcomes, genetic testing results, family and previous pregnancy history, neurological examinations of the born children up to 24 months of age, and autopsy reports of fetuses from terminated pregnancies. MRI-Trio concordance was defined as at least one abnormal brain feature identified with similarity in the fetus and the parents. The live-born children were assessed postnatally through either neurodevelopmental evaluations or telephone interviews.

RESULTS

Sixty pregnancies were included (41.7% with concordant and 58.3% with discordant MRI-Trio). Forty-two children were born (70%) and 17 pregnancies were terminated (28.3%). One case of in utero fetal death (1.7%) was reported. The most common brain findings were multiple anomalies (n = 26, 43.3%), isolated disorders of the corpus callosum (n = 17, 28.3%), atypical periventricular pseudocysts (n = 6, 10%), and anomalies of the anterior complex (n = 4, 6.7%). MRI-Trio enabled better prognostication. When MRI-Trio was concordant, counselling was more favourable (n = 22, 36.6%) and the majority of live-born children exhibited typical development (p < 0.001).

INTERPRETATION

MRI-Trio is a valuable tool for identifying dominantly inherited brain anomalies that may not hold developmental significance or are associated with favourable outcomes, acknowledging the potential for variable penetrance, which may result in more severe presentations. Concordant MRI-Trio findings can enhance the accuracy of prenatal counselling, potentially reducing the incidence of termination of pregnancy.

Overview of reproductive and pregnancy health principles and practice used by maternal-fetal medicine specialists for fetal-neonatal neurology consultants

Unique from other fetal anatomical systems, the central nervous system (CNS) starts development early in the embryonic period shortly after fertilization before most patients are even aware they are pregnant. Maturation throughout pregnancy involve complicated structural and functional changes, most likely below the resolution of testing to detect. During this time, the fetal CNS is susceptible to lesions that reflect trimester-specific adverse events. Neonatal neurological status with childhood sequelae can result from combinations of antenatal, peripartum and neonatal adverse events. Person-specific clinical management choices must consider the timing of multiple mechanisms that can alter neurodevelopment including genetic causes, aetiologies after conception as well as communicable and non-communicable conditions that result in anomalous or destructive brain lesions. The appearance of the fetal brain also changes significantly through gestation as different structures mature and the cerebral cortex in particular increases in size and complexity. Therefore, obstetrical imagers and maternal fetal medicine physicians need to be aware of the expected evolving appearances of the healthy fetal brain as the fetus advances in gestation. Often when fetal CNS pathology is detected or anticipated during pregnancy, there is understandably significant parental anxiety regarding the long-term implications of their child's neurodevelopmental prognosis. In these instances, Maternal Fetal Medicine specialists often collaborate with Pediatric Neurologists in the antenatal period regarding diagnoses that anticipate neonatal or later childhood neurologic sequelae. Potential adverse outcomes are discussed with prospective parents to be integrated into choices based on shared decisions.

Comparison of prenatal central nervous system abnormalities with postmortem findings in fetuses following termination of pregnancy and clinical utility of postmortem examination

OBJECTIVES

In this study, we aimed to compare prenatal ultrasound (USG) and postmortem examination findings of central nervous system (CNS) abnormalities in fetuses following termination of pregnancy (TOP).

METHODS

A total of 190 fetuses with USG-confirmed fetal CNS abnormalities of terminated pregnancies between January 2001 and January 2017 were retrospectively analyzed and USG and postmortem examination findings were compared.

RESULTS

The most frequent CNS abnormalities were acrania/anencephaly (n=45, 24%), spina bifida (n=43, 23%), and ventriculomegaly (n=35, 18%). In 144 of the 190 (76%) cases, there was total agreement between USG and postmortem examination diagnosis. Postmortem examination provided minor findings which did not change the major clinical diagnosis in two (1%) cases with spina bifida and ventriculomegaly. In six (3%) cases, the diagnosis changed after postmortem examination. In 25 of the 190 (13%) cases with multiple abnormalities as evidenced by USG, CNS abnormality was unable to be confirmed at postmortem examination.

CONCLUSIONS

Our study results show an overall high agreement (76%) between USG and postmortem examination findings for CNS malformations. Due to autolysis and fluid structure, USG-confirmed CNS diagnosis cannot be always confirmed by postmortem examination. This potential discrepancy should be explained to patients before considering TOP. Postmortem examination is the gold standard to confirm prenatal diagnosis.

Fetal periventricular pseudocysts: is MRI evaluation needed? What is the long-term neurodevelopmental outcome? Systematic review and meta-analysis

OBJECTIVE

To explore the value of magnetic resonance imaging (MRI) in fetuses with periventricular pseudocysts (PVPC) and the neurodevelopmental outcomes of these fetuses via meta-analysis.

METHODS

MEDLINE and EMBASE database were searched for studies reporting on the MRI assessment of fetuses diagnosed with PVPC on neurosonography. The neurosonography was conducted according to the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG) guidelines or standard axial, coronal and sagittal planes for advanced central nervous system (CNS) assessment. Single-shot fast spin-echo T2-weighted sequences of MRI technique in three orthogonal planes were necessarily performed. The pooled proportion of CNS anomalies missed on neurosonography and detected only at prenatal MRI was calculated. Subanalysis was performed according to the types of intracranial anomalies. The pregnancy outcomes (including normal, abnormal, termination of pregnancy, and perinatal death) of PVPC fetuses were also analyzed.

RESULTS

Five studies comprising 136 fetuses were included in this meta-analysis. Mean gestational age was 29.8 weeks (16-38 weeks) at ultrasonography and 31.5 weeks (25-37 weeks) at MRI. Overall, MRI detected exclusively CNS anomalies in 25.2% (95% CI 15.9-35.8%) of cases. Among them, the highest incidence was white matter abnormalities with the pooled proportion of 16.3% (95% CI 9.7-24.2%). When getting rid of white matter abnormalities, the risk of associated CNS anomalies only detected on MRI was reduced to 9.1% (95% CI 1.8-21.4%). Meanwhile, 130 cases were studied to assess the pregnancy outcomes with the scope of 1 month to 10 years. The pooled proportion of normal outcomes in isolated PVPC fetuses was as high as 95.0% (95% CI 83.9-99.8%). When analyzing the neurodevelopmental outcomes in non-isolated PVPC fetuses, the incidence of normal neurodevelopmental outcomes was about 22.1% (95% CI 5.6-45.5%) with mild and single additional abnormalities, the rate of abnormal neurodevelopmental outcomes was 19.5% (95% CI 11.0-29.7%) with apparent and/or multiple abnormalities. Besides, 53.6% (95% CI 35.4-71.3%) of non-isolated PVPC cases were terminated mainly due to infections, genetic anomalies, metabolic disorders and hemorrhage.

CONCLUSIONS

MRI assessment of PVPC fetuses is recommended to detect associated intracranial anomalies that may be missed on dedicated neurosonography. White matter abnormalities on MRI account for the majority of additional anomalies, which might to be the clue of CMV infection, aminoacidopathy or white matter disease. Moreover, the neurodevelopmental outcome of isolated PVPC fetuses remains favorable, while the neurodevelopmental outcomes of non-isolated PVPC fetuses depend on the accompanying anomaly.

Temporal changes in epidemiological profile and fetal indications for late termination of pregnancy: a retrospective single-center study

PURPOSE

To explore whether epidemiological shifts regarding reproduction and pregnancy have influenced the spectrum of indications for late termination of singleton pregnancies (TOP) above 17 weeks of gestation and to evaluate temporal changes in maternal demographics and fetal indications over the last 16 years.

METHODS

Retrospective single-center cohort study involving all late TOPs preceded by feticide between 1 January 2004 and 31 December 2019 at a tertiary referral hospital in Austria. Outcome variables were retrieved and a time trend assessed between two 8-year intervals (2004-2011 versus 2012-2019).

RESULTS

Between January 2004 and December 2019, a total of 209 singleton pregnancies (50.7% male; 46.9% female fetuses, 2.4% no disclosed sex) were terminated medically at a median gestational age of 25⁺¹ (17⁺³-37⁺¹) weeks at our institution. Predominant conditions legally justifying the late medical abortion were abnormaltities of the brain/central nervous system (n = 83; 39.7%), chromosomal aberrations (n = 33; 15.8%), complex malformations (n = 31; 4.8%) and abnormaltities of the musculosceletal system including diaphragmatic hernias (n = 18; 8.6%), as reflected by the ICD-10-categories "Congenital malformation of the central nervous system", "Other congenital malformations" and "Chromosomal abnormalities". No changes were observed with regards to maternal age (30.1 ± 5.9 vs. 31.0 ± 6.0 years;  p = 0.315) nor frequency of assisted reproductive technologies (7.0% vs. 8.5%; p = 0.550). Despite a 2.5-fold increase in incidence of late TOPs, no epidemiological changes in maternal or fetal characteristics were observed over the last 16 years.

CONCLUSION

Population profile and indications for late TOPs followed by feticide remain unchanged over time.

Autopsy Findings of Central Nervous System Anomalies in Intact Fetuses Following Termination of Pregnancy After Prenatal Ultrasound Diagnosis

OBJECTIVES

Central nervous system (CNS) anomalies are the second most frequent category of congenital anomalies after congenital heart defects (CHDs). In this study, the aim was to investigate the distribution of different CNS anomalies with associated anomalies and karyotype in a fetal autopsy population of terminated pregnancies over a 30-year period and to correlate the ultrasonographic diagnoses of CNS anomalies with autopsy findings.

MATERIALS AND METHODS

This study includes 420 intact fetuses with CNS anomalies terminated at gestational ages 11^+ 0 to 33^+ 6 over a 30-year period from 1985 to 2014. An ultrasound (US) examination was performed at the National Centre for Fetal Medicine, St. Olavs Hospital, Trondheim. The autopsies were performed at the Department of Pathology at the same hospital or a collaborating hospital. The anomalies were subcategorized according to the classification by the World Health Organization.

RESULTS

Neural tube defects such as anencephaly (22.4%, 107/477) and spina bifida (22.2%, 106/477) constituted the most common CNS anomalies, followed by congenital hydrocephalus (17.8%, 85/477). In total, the karyotype was abnormal in 21.0% of all termination of pregnancies (TOPs), with trisomy 18 as the most frequent abnormal karyotype. CHDs, skeletal anomalies, and urinary anomalies were the most common associated organ anomalies. Throughout the study period, there was full agreement between US and postmortem findings of CNS anomalies in 96.9% (407/420) of TOPs.

CONCLUSION

In this study of autopsy findings of CNS anomalies in intact fetuses terminated after prenatal US diagnosis, neural tube defects were most common. About half of the fetuses had isolated serious CNS anomalies, while the other half were CNS anomalies associated with structural and/or chromosomal anomalies. The prenatal US diagnoses were in good concordance with autopsy findings. In particular, due to challenges of diagnoses made early in pregnancy, it is necessary to continue the validation practice.

The association between severe fetal congenital heart defects and placental vascular malperfusion lesions

OBJECTIVE

Studies have shown an association between infant with congenital heart defects (CHD) and the risk of preeclampsia. We aimed to characterize placental histopathology from pregnancies who underwent termination of pregnancy (TOP) because of severe CHD.

METHODS

This was a case control study. The medical files of all TOPs due to fetal congenital malformations were reviewed. Cases with CHD included hypoplastic left heart, transposition of great arteries, AV canal, tetralogy of Fallot, double outlet RV, and coractation of aorta. The controls included TOPs due to congenital central nervous system defects (CNS group) that were matched in a 1:1 ratio, by gestational age and maternal age. Placental lesions were classified to maternal and fetal vascular malperfusion (MVM and FVM) and inflammatory lesions.

RESULTS

Higher rates of any MVM or FVM lesion were observed in placentas from the CHD group (n = 32) as compared with the CNS group (n = 32), 40.6% versus 12.5% respectively, p = .02. As compared with the CNS group, the CHD group had more abnormal coiling of umbilical cord (p = .01).

CONCLUSION

Placental vascular malperfusion lesions are more common in pregnancies complicated with CHD as compared with CNS malformations. These findings support the hypothesis of similar etiopathogenetic factors, contributing to the development of preeclampsia and CHD.