Introduction
Cytomegalovirus (CMV) is a virus of the Herpesviridae family and subtype of beta-Herpes virus that are found sporadically everywhere [1]. The name of the virus is rooted in an cytomegalic inclusion disorder, which is caused by the enlargement of the virus-infected cells. Cytomegalic Inclusin Disease is a type of infectious neonatal infection that infects the baby at birth (2). Cytomegalovirus is the genetically richest source of the most virulent viruses in the family of human herpes virus, with a DNA content of 240 kb. The virus with Fc, like a receptor, binds to cell surface glycoproteins, and can non-specifically stick to Fc immunoglobulins. Its proliferation cycle is slower than herpes simplex of I and II, but the virus is more dependent on the infectious cell [2]. The virus is transmitted from person to person and requires close contact with the substance containing the virus. Its transmission is through body fluids, urine, breast milk, blood, sexual contact, and so on. The Incubation period is about 4 to 8 weeks, resulting in a syndrome similar to that of infectious mononucleosis [1, 2]. The CMV, similar to all other herpes viruses, has two latent and lytic lives [1]. In people with immune deficiency (cancer patients and HIV / AIDS), the virus is excreted long distances from the body, and it spreads to the form of infection, that the most common complication is pneumonia. Usually the host's immune response causes the virus to be hidden in the infected person. Typically, ductal epithelial cells of the body are more infected than fibroblasts, while in vitro, the virus replicates only in fibroblasts. The point is that most people have been infected with the virus throughout their lives and have antibodies to it, but the initial contact with it in the pregnancy period, can cause fetal death. CMV pathogenicity mechanism is the production of proteins that affect the supply of antigen (MHCI) as well as the function of cytotoxic T cells, the production of interferon and interculin 10 immune system, and cause impairment of immunity [2].
HCMV Human Cytomegalovirus is a type of infectious virus at the births, which is one of the most important causes of fetus death before birth. The virus during pregnancy is one of the main causes of deformity and neonatal anomalies [3]. Advanced PCR is a major and important method for detecting various types of genetic disorders that are used to detect many of the viruses that are hidden, such as herpes and the HIV virus [4-6]. CMV is also the most commonly reported infection in patients with immunodeficiency, and one of the main causes of death in these patients [6, 7]. CMV can cause microcephaly, vision problems, hydrocephalus, cardiomegaly and other severe problems in the fetus; it also causes pneumonia, central nervous system (CNS) involvement and heart disease, as well as retinitis in patients with immunological defects.
Clinical signs and CMV complications: Nearly 1% of infants born are infected with the CMV virus (the most common congenital infection in the United States). Of these, 10% have birth symptoms, and 10% to 15% have neurological symptoms or developmental abnormalities during the first year of life [8, 9]. The most common symptoms of this infection are liver and spleen enlargement, brain calcification, jaundice, birth weight loss, coronoid, hearing loss, thrombocytopenia, skin rashes and seizures.
Complications of CMV in infants depend on the time of infection. In the third trimester of pregnancy, the possibility of transmitting infection and severity of conflict is more [8, 9]. Amniocentesis is the most obvious method for diagnosis of CMV infection during pregnancy. The severity of the infection and its complications in ultrasound are revealed by microcephaly, enlargement of the ventricles (ventriculomegaly, calcification, TUGR and oligohydramnios. Each pregnant woman who first contact with CMV and infected, have the possibility of transfer of the virus with ratio of 1 to 3. However, if the virus recurs in the mother's body (recurrent infection), only 1% is likely for fetus to get the infection.
Patient and methods
The report relates to a 27-month-old fetus from a 27-year-old mother in Sarem Hospital, who had not underwent perinatology. In the findings of advanced fetal ultrasonography, regular cardiac movements, and active gastrointestinal movements and organs were observed, and in assessing the location and thickness of the placenta, the characteristics were normal, and in other studies, the amount of amniotic fluid was normal as well. However, signs of brain atrophy and ventriculomegaly were observed. There was no anomalies in the spine and no specific cases were seen in other areas. In a cytogenetic study in the Department of Genetics, a male embryo with normal karyotype was observed, but in autopsy, fetal hydrocephalus and cardiomegaly were observed. Also, in lung examination, large and accumulated pneumocystis were found in PAS staining. According to the pathologic findings of the stained samples by H & E and PAS method, , molecular tests were performed to detect cytomegalovirus in the pathology department, and samples were sent to the molecular pathology department for molecular analysis (Fig. 1).
 

Figure 1) 27-week-old fetus karyotype

 
DNA extraction was then performed on a paraffin block of the embryo with a DNA kit (QIAGEN DNA MiniKi).
After paraffinization, paraffin blocks and extracted DNA were prepared for polymerase chain reaction (PCR) with CMTR1, CMTR2, CMTR3 and CMTR4 primers using Nested method in two steps. The sequence of primers was as follows:
CMTR1: 5-CTGTCGGTGATGGTCTCTTC-3
CMTR2: 5-CCCGACACGCGGAAAAGAAA-3
CMTR3: 5-TCTCTGGTCCTGATCGTCTT-3
C M TR4: 5-GTCACCTACCAACGTAGGTT-3

Description of the steps of PCR: In the first step, with the CMTR1 and CMTR2 primer pair, after preparation of Maste Mix (containing: Taq DNA, dNTP, mgcl2 and polymerase) and adding λ10 from DNA extracted from embryo tissues, the reaction product is obtained according to the following protocol which is used in the next step of the reaction (Table 1).

After obtaining the product of the first step, using the λ5 of this product and preparing Master Mix, the performance was as in the previous step, with the CMTR3 and CMTR4 primers according to the first protocol, except that this time the test steps were performedwith 20 cycles in thermo cycler. As a result, the bp168 band was obtained which indicated the presence of CMV (Fig. 2).

Fig. 2) Observing 168bp band in patient samples compared to positive and negative controls on both sides of the 50bp Ladder

 
Discussion
Similar results have been obtained from previous studies on the symptoms and complications of cytomegalovirus virus. For instance, a case report of a 31-week -old neoplasm with hepatosplenomegaly and thrombocytopenia, without abnormalities can be mentioned who died after birth due to respiratory problems on the 14^th day of the birth. After autopsy and microscopic examination on the organs of the infant, it was shown that cytomegalic cells were present in the liver, spleen, adrenal and thyroid gland, as well as large eosinophilic cells in the kidney,  but cellular changes in the lung were not observed [10] . In that report, the applied method was the Nested-PCR reaction on dead infant tissues that was used after extraction of DNA from paraffin tissues (FFPE) [10, 11].

Conclusion
Considering the healthy karyotype and the absence of genetic problems and molecular studies, the main cause of the changes in the fetus, including cardiomegaly and hydrocephalus, as well as the cause of death in the 27-week –old fetus, is cytomegalovirus.

Acknowledgments
The case was not found by the authors.
Ethical permissions
The case was not found by the authors.
Conflict of Interest
The case was not found by the authors.
Financial support
This study was supported by Sarem Fertility and Infertility Research Center.
Contribution of authors
Masoomeh Hassani (First author), author of the article/main author (%50); Kian Bagher (Second author), author of the article/methodology/main author/author of discussion (%50).