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ORIGINAL ARTICLE
Year : 2012  |  Volume : 39  |  Issue : 2  |  Page : 81-84

Anencephaly: A pathological study of 41 cases


Department of Pathology, KLE University's Jawaharlal Nehru Medical College, Belgaum, Karnataka, India

Date of Web Publication1-Oct-2012

Correspondence Address:
C Panduranga
Department of Pathology, J. N. Medical College, Belgaum - 590 010, Karnataka
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0974-5009.101852

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  Abstract 

Background : Anencephaly is a lethal neural tube defect which is due to the defective closure of rostral pore of neural tube. In more than 50% of cases it is associated with other systemic anomalies. Hence this study was undertaken to assess pathological parameters associated with anencephaly in particular attention to associated systemic anomalies. Materials and Methods: It is a study on 41 anencephaly fetuses conducted in the Department of Pathology. The period of study is from January 2001 to December 2011. Results: Out of 41 cases, 30 (73%) cases showed presence of systemic anomalies, 48.5% of the cases were observed in primigravida. Most common associated anomaly was spina bifida followed by gastrointestinal anomalies. Conclusion: Pathological examination of the abortus is essential to document the associated anomalies.

Keywords: Anencephaly, fetal autopsy, neural tube defects, systemic anomalies, spina bifida


How to cite this article:
Panduranga C, Kangle R, Suranagi VV, Pilli GS, Patil PV. Anencephaly: A pathological study of 41 cases. J Sci Soc 2012;39:81-4

How to cite this URL:
Panduranga C, Kangle R, Suranagi VV, Pilli GS, Patil PV. Anencephaly: A pathological study of 41 cases. J Sci Soc [serial online] 2012 [cited 2017 Sep 21];39:81-4. Available from: http://www.jscisociety.com/text.asp?2012/39/2/81/101852


  Introduction Top


Anencephaly is a common and lethal neural tube defect (NTD) which occurs due to the defective closure of rostral pore of neural tube. It is also known by other names like acrania (absence of skull), acephaly (absence of head), merocrania and meroanencephaly. Anencephaly can be diagnosed by ultrasound examination (USG) and by elevated maternal alpha feto protein level, but pathological examination of the abortus is needed, as in most of the cases anencephaly is associated with systemic anomalies. [1] On reviewing the literature there are only few studies of this kind from India. [2] Hence this study was undertaken to assess the pathological parameters associated with anencephaly with particular attention to associated systemic anomalies.


  Materials and Methods Top


This is a study on 41 cases of anencephaly conducted in the department of pathology at a medical college and teaching hospital for a period of 11 years from January 2001 to February 2011. The study was retrospective from January 2001 to July 2010 (9 years, 6 months) and prospective from August 2010 to December 2011 (one year, six month). For retrospective cases autopsy findings were retrieved from the autopsy files of the department. For prospective cases after obtaining informed consent, autopsies were performed or supervised by one of the above authors by a standard protocol. The autopsies included reading of the clinical findings, external examination, photography and internal examination. All the observations were recorded paying more attention to associated systemic anomalies. The cases were originated from still birth, spontaneous and therapeutic abortion. The statistical analysis was performed by using frequency and percentage.


  Results Top


  1. Age: Minimum age of the mother observed in our study was 19 years and maximum was 28 years with mean of 23 years.
  2. Parity: Out of 41 mothers 20 were primigravida (48.5%), four were gravida 2 (10%), 13 were gravida 3(31.5%) and four case were gravida 4(10 %).
  3. Sex: Out of 41 fetuses, 27 were female, nine were male and five fetuses had ambiguous genetalia.
  4. Gestational age: Gestational age ranged from 16 to 34 weeks with mean of 21 weeks.
  5. Head circumference: It ranged from 9 to 14 cms with mean of 11.4 cms
  6. Associated anomalies: Out of 41, 30 cases showed associated systemic anomalies constituting 73%. The brain was replaced by angiomatous tissue and cerebellum was rudimentary to absent [Figure 1]. Other Central nervous system (CNS) anomalies observed were spinabifida in 11 cases and craniospinal rachinoschisis in five cases [Figure 2]a. The only anomaly identified in the face was cleft lip and palate in one case. The only anomaly observed in lung was simple cyst in one case. The six gastrointestinal anomalies observed were absence of intestinal coils, diaphragmatic hernia, marked ascites, imperforate anus and situs inversus each in one case and omphalocele in two cases [Figure 2]b. The six skeletal anomalies observed were achondroplasia [Figure 3], kyphoscoliosis, equinovarus, absent femur and absent vertebral column [Figure 4]a-b each in one case. Long fingers were observed in two cases. The cardiovascular anomalies noted are single umbilical artery in five cases and one case of segmental duplication of umbilical artery [Table 1]. We did not observe any urinary anomalies in our study.
Figure 1: Photograph showing angiomatous tissue in place of developing brain.

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Figure 2: (a) Photograph showing anencephaly with craniospinal rachinoschisis. (b) Photograph showing anencephaly with omphalocele.

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Figure 3: Photograph showing anencephaly with achondroplasia.

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Figure 4: (a) Photograph showing anencephaly with agenesis of vertebral column and spinal cord. This on dissection showed absence of intestinal coils. (b) Microphotograph from the mass in the vertebral region of Figure 4a, showing rudimentary intestine, cartilage, and neural tissue. (H and E, ×400)

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Table 1: Systemic anomalies associated with anencephaly

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  Discussion Top


The prevalence of anencephaly shows great variation in time and space. It is 12 per 10,000 in Iran, 10.4 per 10,000 in china, 0.01 to 7.42 per 10,000 in Rijeka Crotia, 1.49/1000 in Santos Dumout, [3] 0.5 to 0.6 per 1000 live births in Singapore [4] and 0.5 to 6.5 per 1000 live births in India. [5],[6],[7],[8],[9]

The commonest child bearing age of women in India is 20- 28 year. [10] Mean age of the mother observed in our study is 23 years (ranged from 19-28 years) and our findings are consistent with published literature. [2] In contrast, Caffy et al. [11] Edward [12] and Golalipour et al. [3] observed prevalence of anencephaly more in women aged above 35 years. 48.5% of our cases were primigravida and findings are comparable to the literature. [2] Parity and maternal age did not have any association with the etiology and outcome with respect to neural tube defects except for open neural tube defects which are observed more in primigravida same as also been observed in our study. [6]

Female fetuses outnumbered the male fetuses (0.33) as observed by previous authors. Out of 41 cases, 30 showed presence of anomalies constituting 73%. The reported incidence of associated anomalies range from 9.4 to 43%. [2],[3],[4],[13],[14],[15] We have observed more number of associated anomalies than reported in literature. We have observed 11 cases of spina bifida, out of which five were isolated spina bifida and six were associated with systemic anomalies, and our findings are in consistent with the literature. [15] Outside the C.N.S, skeletal and GIT anomalies were common constituting 14.5% each and our findings are consistent with Vare et al. [2] and Tan et al. [4] Incontrast, Goliapure et al. [3] and Nielson et al. [13] observed skeletal anomalies as the most common second anomalies. David et al. [14],[15] in his two studies on anencephaly in Bristol and Lancashire observed renal anomalies (16.3%) in the later and cardiovascular (10.9%) in the former as the most common anomalies. They also suggested that the differences may be due to different time of the study and also due to genetic and racial differences. We have also observed cardiac anomalies in 6 cases but all of them were Umbilical cord defect none showed structural cardiac defects. In addition, we have identified a rare case of absent spinal cord, vertebral column and GIT simulating like meningocele but, microscopy showed developing three germ layers which is not observed in the literature. The comparison of anomalies observed in the literature is shown in the [Table 2].
Table 2: Shows comparison of pathological parameters (values in percentage)

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NTDs are considered to be polygenic, multifactorial condition wherein many genes, nutrients, environmental factors including infections, drugs and maternal disease like diabetes individually or in combination play a role. [10] The maternal risk factors that are associated with anencephaly are illiteracy, increasing gravidity, history of previous miscarriages, positive history of birth defects, high or low age of mothers during pregnancy, increased stress, women employed in industry or agriculture, low socio-economic status and maternal antipyretic consumption. However there was no association with paternal age and paternal exposure to chemical or physical agents. [3]

The major thrust of primary prevention of NTDs has been on nutritional supplementation with folic acid apart from controlling the maternal diseases like diabetes and avoiding medications. Role of 0.4 mg of periconceptional folic acid leading to reduction in NTDs was demonstrated by MRC, [16] and also by Kulkarni et al. in India. [17] Currently there is no national program for primary prevention of NTD in India. National anemia prevention program provides 0.5 mg of folic acid along with 100mg of elemental iron from third month of pregnancy. The recent National Family Health Survey (NFHS-3) revealed that about 56% of pregnant women sought antenatal care after 16 weeks of gestation as observed in our study also. Thus only a small percentage of women receive Periconceptional folic acid supplementation. [10]

Fifty four countries including India are practicing fortification of flour with folic acid. There was a decline in the incidence of anencephaly after fortification in USA, South Africa, Canada and Singapore. Fortification of flour in India is not uniform; it varies from state to state with highest percentage in Gujarat. The benefit of fortification of flour still needs to be established in India. Fortification of folic acid is a two edge sword as it may cause prevention of anencephaly but is a risk factor for colorectal cancer and neuro-cognitive decline [3],[4],[10]

Even though anencephaly can be diagnosed as early as 11-14 weeks of gestation by USG and by measuring the values of serum alpha feto protein level in maternal blood but autopsy is the gold standard to document the associated systemic anomalies. [1],[2],[4]


  Conclusion Top


Anencephaly is commonly associated with other systemic anomalies; the observed percentage in the present study is 73%, Gastrointestinal and skeletal system are more commonly involved. Even though USG can detect this anomaly as early as 14 weeks neonatal autopsy is needed to document all associated anomalies. Prospective studies of more number of cases with genetic analysis will uncourten the possible association of associated anomalies.


  Acknowledgement Top


We acknowledge, all faculty members of Dept of OBG, JNMC for providing fetuses for study.

 
  References Top

1.Moore LK, Persaud TV. Editors. The developing Human. Philadelphia: Saunders; 1998. p. 478-9.  Back to cited text no. 1
    
2.Vare AM, Bansal PC. Anencephaly. An Anatomical study of 41 anencephalies. Indian J Pediatr 1971;38:301-5.  Back to cited text no. 2
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3.Golalipour MJ, Najafi L, Keshtkar AA. Prevalence of Anencephaly in Gorgan, northern Iran. Arch Iran Med 2010;13:34-7.  Back to cited text no. 3
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4.Tan KB, Tan SH, Tan KH, Yeo GS. Anencephaly in Singapore: a ten-year series 1993 - 2002. Singapore Med J 2007;48:12-5.   Back to cited text no. 4
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5.Bhat BV, Babu L. Congenital malformations at birth- A prospective study from south India. Indian J Pediatr 1998;65:873-81.  Back to cited text no. 5
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6.Mahadevan B, Bhat BV. Neural tube defects in Pondicherry. Indian J Pediatr 2005;72:557-9.  Back to cited text no. 6
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7.Agarwal SS, Singh U, Singh PS, Singh SS, Das V, Sharma A, et al. Prevalence and spectrum of congenital malformation in a prospective study at a teaching hospital. Indian J Med Res 1991;94:413-9.  Back to cited text no. 7
    
8.Sood M, Agarwal N, Verma S, Bhargava SK. Neural tubal defects in an East Delhi hospital. Indian J Pediatr 1991;58:363-5.  Back to cited text no. 8
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9.Kulkarni ML, Mathew MA, Ramachandran B. High incidence of Neural tube defects in south India. Lancet 1987;8544:1260.  Back to cited text no. 9
    
10.Coffey VP, Jessop WJ. A study of 137 cases of anencephaly. Br J Prev Soc Med 1957;11:174-80.  Back to cited text no. 10
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11.Edward JH. Congenital malformations of the central nervous system in Scotland. Br J Prev Soc Med 1958;12:115-30.  Back to cited text no. 11
    
12.Wei PY, Chen YP. Congenital malformations, especially anencephalus, in Taiwan. Am J Obstet Gynecol 1965;91:870-6.  Back to cited text no. 12
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13.Nielsen LA, Maroun LL, Broholm H, Laursen H, Graem N. Neural tube defects and associated anomalies in a fetal and perinatal autopsy series. Acta Pathol Microbiol Immunol Scand 2006;114:239-46.  Back to cited text no. 13
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14.David TJ, McCrae FC, Bound JP. Congenital malformations associated with anencephaly in the Fylde peninsula of Lancashire. J Med Genet 1983;20:338- 41.  Back to cited text no. 14
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15.David TJ, Nixon A. Congenital malformation associated with anencephaly and inencephaly. J Med Gen 1976;13:263-5.  Back to cited text no. 15
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16.MRC Vitamin Study Research Group. Prevention of neural tube defects: Results of the Medical Research Council Vitamin Study. Lancet 1991;338:131-7.  Back to cited text no. 16
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17.Kulkarni ML, Jose S. Folic acid prevents neural tube defects in high prevalence area. Indian Pediatr 1997;34:561-2.  Back to cited text no. 17
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    Figures

  [Figure 1], [Figure 2], [Figure 3], [Figure 4]
 
 
    Tables

  [Table 1], [Table 2]



 

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Abstract
Introduction
Materials and Me...
Results
Discussion
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Acknowledgement
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