Neural tube defects (NTDs) are among the most common congenital malformations, occurring in about 0.5–2 per 1,000 live births [1]. They result from failure of the neural tube to close during the third to fourth week of embryonic development [2]. Spinal dysraphism, particularly meningocele and myelomeningocele, forms a major group of NTDs, with outcomes varying according to the site, size, and associated anomalies [3].

Meningocele is characterized by a cerebrospinal fluid (CSF)-filled sac protruding through a vertebral defect, enclosed by meninges but without herniation of neural tissue [4]. Although regarded as a less severe form of NTD compared with myelomeningocele, its recognition remains clinically significant [5]. Prenatal diagnosis facilitates timely parental counseling, assessment for associated anomalies, and informed decisions regarding pregnancy management and specialized perinatal care [6].

Conventionally, most spinal anomalies are identified during the second-trimester anomaly scan (18–22 weeks) [7]. With recent advances in ultrasonography, including high- resolution transvaginal probes and three-dimensional imaging, subtle structural abnormalities can now be detected as early as the late first trimester (11–14 weeks) [8].

Early diagnosis of meningocele at this stage enables timely intervention, closer surveillance, and more informed reproductive decision-making [9].

Despite this, published literature on first-trimester detection of meningocele remains limited, especially regarding longitudinal follow-up and correlation with pregnancy outcomes. Larger case series are needed to validate diagnostic accuracy, clarify prognostic implications, and inform future clinical guidelines [10].

Research Objectives

The present study aims to:

1. Evaluate the sonographic characteristics of meningocele detected at even 11–14 weeks of early gestational age (NT scan).
2. Assess the incidence and distribution of meningocele in a cohort of approximately 100 pregnancies with suspected anomalies about neurology.
3. Correlate first-trimester findings with pregnancy outcomes, including continuation, termination, and neonatal prognosis.
4. Highlight the role of first-trimester ultrasound as a reliable tool for early detection of spinal dysraphism

Study Design: A prospective observational case series conducted in a tertiary care fetal medicine and radiology center.

Study Population:

• Inclusion criteria: Pregnant women undergoing routine first-trimester scan (11–14 weeks) with fetuses diagnosed with meningocele.
• Exclusion criteria: Incomplete data, loss to follow-up, or absence of definitive meningocele diagnosis.

Sample Size: 100 pregnancies with suspected anomalies about neurology with 3 confirmed meningocele diagnosis including one case of a small (sub centimeter) meningocele.

Imaging Protocol:

• Transabdominal ultrasound with high-frequency probes; transvaginal scan when lesion characterization was suboptimal.
• Parameters recorded: gestational age, size of sac, lesion location (cervical, thoracic, lumbar, sacral), associated anomalies, and nuchal translucency.

Data Collection:

• Maternal demographics (age, parity, medical history).
• Follow-up outcomes: continuation of pregnancy, elective termination, perinatal survival, and neonatal neurological status.

In our series of 100 pregnancies with suspected anomalies about neurology, 3 cases of meningocele were diagnosed at 11–14 weeks, including one case of a small (even sub centimeter size) meningocele, which was particularly challenging to detect at an early gestational age, yet successfully diagnosed at our center. The distribution by location, size, and outcomes was analyzed. The majority of lesions were located in the lumbosacral region. In our study, associated anomalies were, Hydrocephalus and ductus venosus flow abnormalities. Pregnancy continuation was seen in 33% of cases, while 33% opted for elective termination. In our Research study after few days we did follow up and outcome was Intrauterine Fetal Death.

Table 1: Relative frequency of major neural tube defects (as per previous studies and data acquisition).

Table 2: Distribution of meningocele cases by lesion site (as per previous studies and data acquisition).

Table 3: Pregnancy outcomes in the study population (as per previous studies and data acquisition).

Flowchart: Neural Tube Defects – Classification and Detection Pathwa

Foetal lower spine: shows hypoechogenicity (Cystic lesion) of size 9.3mm x 4.3 mm along the lower lumbo-sacral spine with probably underlying Spina bifida.

This prospective case series highlights the feasibility of early detection of even small (sub centimeter) size meningocele during the first-trimester scan. Our findings are consistent with existing literature, where spinal dysraphism is most commonly observed in the lumbosacral region. The ability to diagnose meningocele at 11–14 weeks allows earlier counseling and reproductive decision-making compared to the conventional second- trimester anomaly scan.

In our study, approximately 33% of couples opted for elective termination, reflecting the significant psychosocial impact of early diagnosis. Live births accounted for 33% of the cohort, with most survivors having varying degrees of neurological impairment. Compared with myelomeningocele, isolated meningocele may have a relatively favorable prognosis if no additional anomalies are present. However, the risk of associated abnormalities, including hydrocephalus and Chiari malformations, necessitates detailed follow-up.

Strengths of this study include the relatively large sample size for a first-trimester series and prospective data collection. Limitations include absence of genetic testing in all cases, limited neonatal follow-up, and single-center design. Further multicentric studies with standardized follow-up protocols are required to refine prognostic counseling.

First-trimester ultrasound provides a reliable modality for early detection of even small (sub centimeter size) meningocele and other neural tube defects. The ability to detect anomalies as early as 11 to 14 weeks offers families the opportunity for timely counseling, reproductive choice, and optimized perinatal planning. Our study underscores the importance of incorporating detailed spinal evaluation into the routine first-trimester scan.

1. Greene, Nicholas D. E., and Andrew J. Copp. "Neural Tube Defects." Annual Review of Neuroscience, vol. 37, 2014, pp. 221–242. https://doi.org/10.1146/annurev-neuro-062012-170354.
2. Zaganjor, Ibrahim, et al. "Describing the Prevalence of Neural Tube Defects Worldwide: A Systematic Literature Review." PLoS ONE, vol. 11, no. 4, 2016, e0151586. https://doi.org/10.1371/journal.pone.0151586.
3. Syngelaki, Athina, et al. "Challenges in the Diagnosis of Fetal Non-Chromosomal Abnormalities at 11–13 Weeks." Prenatal Diagnosis, vol. 31, no. 1, 2011, pp. 90–102. https://doi.org/10.1002/pd.2631.
4. Volpe, Pasquale, et al. "Diagnosis of Open Spina Bifida at 11–13 Weeks." Ultrasound in Obstetrics & Gynecology, vol. 50, no. 1, 2017, pp. 23–29. https://doi.org/10.1002/uog.17457.
5. Souka, Aphrodite P., et al. "Assessment of Fetal Anatomy at the 11–14-Week Ultrasound." Ultrasound in Obstetrics & Gynecology, vol. 28, no. 7, 2006, pp. 922–926. https://doi.org/10.1002/uog.3869.
6. International Society of Ultrasound in Obstetrics and Gynecology (ISUOG). "Practice Guidelines: Performance of First-Trimester Fetal Ultrasound Scan." Ultrasound in Obstetrics & Gynecology, vol. 41, no. 1, 2013, pp. 102–113. https://doi.org/10.1002/uog.12342.
7. Nicolaides, Kypros H. "Screening for Fetal Abnormalities at 11 to 13 Weeks." Prenatal Diagnosis, vol. 31, no. 1, 2011, pp. 7–15. https://doi.org/10.1002/pd.2684.
8. Chaoui, Rabih, et al. "Assessment of Intracranial Translucency in the Detection of Spina Bifida at the 11–13-Week Scan." Ultrasound in Obstetrics & Gynecology, vol. 34, no. 3, 2009, pp. 249–252. https://doi.org/10.1002/uog.6413.
9. Salomon, Ludovic J., et al. "Practice Guidelines for Performance of the Routine Mid-Trimester Fetal Ultrasound Scan." Ultrasound in Obstetrics & Gynecology, vol. 37, no. 1, 2011, pp. 116–126. https://doi.org/10.1002/uog.8831.
10. Rossi, Angela C., and Federico Prefumo. "Accuracy of Ultrasonography at 11–14 Weeks of Gestation for Detection of Fetal Structural Anomalies: A Systematic Review." Obstetrics & Gynecology, vol. 129, no. 6, 2017, pp. 1021–1030. https://doi.org/10.1097/AOG.0000000000002059.