Management of Prenatally Diagnosed Malformations of the Central Nervous System: Factors Influencing Decision-making and the Time of Termination of Pregnancy

Abstract

Introduction

CNS malformations are among the most common malformations diagnosed prenatally and one of the main reasons for late terminations of pregnancy. Making the correct diagnosis and prognostic counseling a33re complex. The aim of this study was to analyze pregnancy outcomes with regard to specific malformations, the factors which affect decision-making, and the time between diagnosis and termination as well as the causes of late diagnosis and late termination.

Patients and Method

A retrospective examination was carried out of all pregnancies with fetal CNS malformations treated at a perinatal center between 2003 and 2014. Termination rates, type of malformation, and gestational age at initial diagnosis and at termination were recorded. The factors influencing decision-making and the time between diagnosis and termination were analyzed statistically. A case-by-case analysis was carried out of any terminations performed after week 26+0 of gestation.

Results

In 139 of 251 cases (55.44%), the pregnancy was terminated between week 13+1 and week 38+2 of gestation (median: 22+4 GW). The median time from the initial diagnosis to the start of termination (Δtermination) was 10 days (range: 1 to 94 days). Relevant factors influencing the decision to terminate the pregnancy were the type of malformation compared to isolated ventriculomegaly (non-isolated ACC [aOR 17.5; p < 0.001], holoprosencephaly [aOR 24.4; p < 0.001], spina bifida [aOR 7.24; p < 0.001], other neural tube defects [aOR 62.5; p < 0.001]) and the presence of additional genetic anomalies (aOR 6.38; p = 0.014). The decision to terminate the pregnancy occurred less often when the diagnosis was made at or after week 22+0 of gestation (aOR 0.24; p < 0.001). Significant factors which affected the time between diagnosis and the start of termination (Δtermination) were: having a fetal MRI (HR 0.41; p = 0.003) and maternal age (HR 0.95 per additional year; p = 0.034). The interval between diagnosis and termination was significantly shorter if a destructive abnormality (HR 10.5; p = 0.004) or a (non-spina bifida) neural tube defect (HR 3.86; p = 0.002) was present. A known chromosomal aberration (p = 0.87), non-CNS anomalies (p = 0.58), or a diagnosis ≥ 22+0 GW (p = 0.74) affected the time between diagnosis and termination. The analysis of particularly late terminations from week 26+0 of gestation onwards found that avoidable delays in making the diagnosis or terminating the pregnancy only occurred in a few individual cases.

Conclusion

The diagnostic and prognostic complexity of cerebral malformations means that delayed diagnosis and prolonged decision-making are common, even under optimal conditions of care. Early introduction of standardized prenatal diagnostic examinations is needed for to ensure that the pregnant woman receives open-ended, informed counseling as soon as possible. But late termination of pregnancy is not necessarily negative as, in most cases, this is due to the need for a differentiated prenatal diagnostic evaluation – for example, a fetal MRI – and the ethical requirement of sufficient time to provide informed, well-considered decision-making.

Keywords

late termination - fetocide - fetal CNS malformation - fetal neural tube defect

Publication History

Received: 14 February 2025

Accepted after revision: 22 June 2025

Article published online:
02 September 2025

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