ARTICLE INFO

Article Type

Original Research

Authors

Sarafzadeh   A. (*)
Jamalou   M. (1)
Roustaei   Z. (2)






(*) Sarem Fertility & Infertility Research Center (SAFIR)‎, Sarem Women’s Hospital, Tehran, Iran
(1) ‎Information Technology (IT) Department, Management Faculty‎, University of Tehran‎, Tehran, Iran
(2) Sarem Fertility & Infertility Research Center (SAFIR)‎, Sarem Women’s Hospital, Tehran, Iran

Correspondence

Article History

Received:  January  15, 2017
Accepted:  May 14, 2017
ePublished:  June 15, 2018

BRIEF TEXT


‎... [1]. Placenta is considered as the main source of oxygen supply and blood supply to the fetus and ‎plays a major role in its growth [2, 3].‎

Abnormal growth of placenta is associated with negative pregnancy outcomes, one of the most ‎important consequences of which is preterm labor. Preterm labor is birth before the 37th week of ‎pregnancy and is the leading cause of infant mortality [4] … [5]. Various studies have been done to find ‎effective factors in preterm labor, based on which maternal factors such as infection, bleeding, uterine ‎and cervical factors, history of previous pregnancies, demographic factors and factors such as ‎oligohydroamnios and polyhydroamnios, diabetes mellitus and high blood pressure in pregnancym ‎and fetal factors such as anomaly of the nervous system have been confirmed as effective factors in the ‎occurrence of preterm labor. [6-8]. All of these factors have a direct effect on the placenta.‎ These complications are sometimes to the extent that it causes the death of the fetus within the uterus ‎and, since one of the rare causes of sudden death of the fetus, is the infarction of the placenta at its ‎maternal level, in all cases of fetal death, placenta should be pathologically evaluated [9]. … [10-14]. Recently, targeted principles have been developed to examine placenta based on fetal-placenta ‎indication. For example, the American College of Obstetricians and Gynecologists (ACOG) has ‎suggested that studying all placenta is not justified and we must decide which placenta to choose for ‎pathological evaluation [15]. According to the protocol provided by the College of American Pathology ‎‎(CAP) in 1997, all placenta should be examined and triaged in the labor room, and abnormal placenta ‎‎(according to the indications provided) should be sent to the laboratory for pathological assessments ‎‎[10] (Table 1) . In the IUFD embryos where the cause of fetal death is unclear and parents are not ‎satisfied with autopsies, the pathologic evaluation of the placenta shows its value correctly [16].‎The aim of this study was to investigate the pathology of the placenta in preterm labor and prediction ‎of neonatal complications and outcomes.‎



This is a descriptive cross-sectional study.‎

In a one-year interval, the placenta samples of preterm labor that had occurred in the Sarem Women ‎Specialized Hospital were investigated.‎

The inclusion criteria included single pregnancy and maternal gestation before 37 weeks of gestation, ‎no history of smoking, non-alcohol and drug use, and age from 20 to 40 years. Of the total number of ‎placentas transmitted to the pathology laboratory, 118 placenta were indicative of preterm delivery, ‎and 120 cases were excluded due to ambiguity in the required indications, including positive cases of ‎screening tests for abnormalities and common trisomies, infectious diseases (TORCH) during ‎pregnancy and a history of severe trauma during pregnancy.‎

The pathological study of the placenta was performed according to international laws and medical ‎ethics, and according to agreed indices of the obstetrician and pathology department and ethically ‎confirmed and all samples were taken from deliveries performed at Sarem Specialized Hospital. All newborns were examined at birth and delivered to neonates department with Apgar equal to 7 and ‎above. All placentas were triaged in the labor room, those with any apparent anomalies were sent to ‎the Pathology Lab for clinical evaluation of pathology according to the CAP protocol. The placentas ‎were investigated in the formalin 10% macroscopically after one day [15]. According to the protocol of ‎the passing of the placenta (Ref) from maternal-embryo and umbilical cord area, each of them received ‎at least 3 pieces and placed in a tissue processing machine for processing, and after 18 hours of tissue ‎processing, blocking was performed and from each block two slides were prepared and The H & E ‎method was used for staining and was microscopically investigated by the pathologist. Macroscopic ‎features included size, maternal level, embryonic level, lobulation, membrane transparency, ‎hematoma and Umbilical length. The microscopic features also include trophoblastic cells, maternal ‎and fetal lungs, fibrinoid depilation, focal inflammation, basal plate necrosis, fetal vessels in chorionic ‎plate, fibrosis, fetal art, vasculature, syncytial knots, core angiogenesis, meconium staining, and ‎microcalcification.‎ The data were analyzed by the method of logistic regression analysis using the Forward field selection ‎method and in order to select the number of appropriate records (observations) for regression ‎analysis, all the records that were of high prevalence were selected and then the various diagnostic ‎tests for the pathology of their placenta were Checked out. Observations with an absent value were ‎considered as normal and other observations that were present were considered as abnormal class. ‎

The data of all the placenta that were sent to the pathology lab due to the preterm reason were analyzed ‎in three stages (Table 2).‎‎106 placentas had no other reasons to send, and the only reason for sending placentas was preterm ‎delivery, and in the case of other placentas, in addition to preterm delivery, there were other reasons ‎for sending. These placentas were set aside for further analysis. Therefore, out of 118 placentas ‎submitted for early delivery, 106 cases were entered into the next stages of analysis. Due to the low ‎number of samples due to the preterm delivery of mother, the prediction accuracy of the model was ‎‎68.6% (Table 2).‎ The logistic regression model was used to analyze the factors influencing the prevalence, including the ‎study of the effect of 14 independent input variables (variables examined in the pathology of the ‎placentas) on the predominant dependent variable. Input variables based on the results of pathologic ‎testing were 106 placentas of preterm labor, the only reason for their transmission to the pathology lab ‎was only preterm labor. In the study of pathologic results, the highest results were observed for ‎placentas that did not show pathological changes (absent), which contained 89.5% of the total ‎pathological outcomes and 10.10% of the results indicated positive presence of present pathological ‎changes in the resulting preterm placentas. The final model was able to predict 68.6% of the records, ‎so that 106 of the preterm cases were correctly diagnosed (Table 2).‎ In the group where the results of their pathological examination were positive and histological changes ‎were observed (of the 14 variables examined in the pathology of the placenta), three varices of ‎syncytial knot, core angiogenesis and microcalcification were effective variables that had the most ‎effect on the diagnosis of pathologic outcomes. The level of parent's statistic and their significant level ‎showed a significant relationship between their presences in the model. According to this, the increase ‎in a unit in the syncytial knot present increases the odds of generating a preterm by an average of ‎‎0.01percent. Also, the change in the amount of variance in the preterm core angiogenesis effects was ‎‎0.252 and the change in the amount of microcalcification variable from the normal to the abnormal ‎state increased the chance of a predominant occurrence by an average of 0.14 (Table 3). The diagnostic power of the model was to predict the effective pathologic changes in the tissue of the ‎placenta in the range of 67.6 to 71.2 with a mean of 69.12. Also, 3 independent variables of syncytial ‎knot, core angiogenesis and micro calcification in all models were considered as effective variables.‎ SE value = the standard deviation calculated based on the degree of freedom df and the parent's ‎statistic. Significance level or p-value indicates that all three parameters are statistically significant. The value of sig or p-value, which indicates that the three parameters are statistically significant The exp (B) as the ratio of odds indicates how much increase in this parameter can increase or ‎decrease the chance of occurrence of the target field.‎

‎... [17, 18]. Pathologic changes in the tissue of placenta are only observed in 10.0% of the placentas, ‎Therefore, it can be concluded that only preterm delivery cannot lead to histopathological changes in ‎the placenta, and, on the other hand, results in a group with histopathological changes (Present group) ‎also shows that the levels of syncytial knot, microcalcification and core angiogenesis in placenta can ‎have the greatest effect on pathological changes and are more effective than other variables in ‎determining the pathological changes in the placental tissue. Studies have shown that due to the importance of oxygenation and the transfer of food from the ‎placenta to the fetus [19], calcification of placenta, especially in preterm labor, causes complications ‎such as decreased fetal growth, Apgar's decline, etc. in the fetus, and can result in pregnancy [20]. ‎Therefore, calcification can be considered as a complication that affects the placental tissue and causes ‎pathological changes in the tissue and matches the findings of this study. ‎... [21]. Core angiogenesis is a complication that occurs in mild hypoxia of the fetus and causes ‎abnormalities in placenta. As previously mentioned, morphologic features of the placenta villus are ‎angiogenesis, which is called corneal angiogenesis if anorexia is exaggerated [22]. Syncytial node is said to be the focal concentration of syncytial nuclei in the placenta villi, which is ‎rarely seen in immature placenta and increases gradually with the advent of gestational age [23, 24] ‎and is one of the factors for the diagnosis of adult placentas. Therefore, in early preterm delivery, we ‎see the decrease of the amount of syncytial knot.‎





Pathologic changes including syncytial knot, microcalcification and core angiogenesis have the most ‎effect on the pathology of the placenta in preterm labor.‎





The pathology of the placenta was examined and ethically confirmed in accordance with international ‎laws and ethical medical considerations, with regard to the agreed indices of the gynecologist and ‎pathology department.‎



TABLES and CHARTS

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