Estudio multidisciplinar de la Muerte Súbita e Inesperada del Lactante en la Comunidad Valenciana. 2006-2017. Estrategia de análisis y prevención
Sudden Infant’s Death Syndrome (SIDS) is defined as the death of an infant less tan one year of age that apparently occurs during sleep and remains without an explanatory cause after a thorough post-mortem investigation that includes autopsy and circumstances surroundig the causes of death and review of the clinical record. The pathogenesis of SIDS has been understood using the triple risk hypothesis. The incidence rate of SIDS has undergone a brisk reduction amounting at present 0,2-0.5 cases per 1000 live births while keeping stable in the latter years. Risk factors associated with infant’s sleep that generate an insecure environment include sleeping in prone position, sharing bed with parents and/or family members especially if the latter are tired or smoke, consume alcoholic beverages, illegal or sedative, co-sleeping outside the bed and overheating. Protective factors that prevent SIDS include sleeping in supine position, upon a hard mattress, avoiding pillows and other objects inside the crib, exclusive breastfeeding, sleeping in a crib in the same room as the parents, aerated room, the use of pacifier, to avoid smoking during gestation and/or and complete the vaccinations schedule. San Diego’s classification renders extremely useful for certification, epidemiological studies and SIDS classification in categories. Autopsy is mandatory for the investigation of SIDS since it may have legal, health and social-family implications. SIDS is multifactorial and complex, and requires a multidisciplinary team for an adequate approach. Aims. To investigate and analyze the characteristics and proceed to classify SIDS in infants less than one year of age deceased in the Community of Valencia and obtain an epidemiological profile of the victims, and evaluate the degree of knowledge of SIDS in the general population upon the risk and protective factors. Material and Methods This is a prospective, observational, transversal, and descriptive cohort study performed in the Community of Valencia from September 2006 to December 2017 and subjected to a multidisciplinary approach applying San Diego’s Classification after performing legal autopsy in the Legal Medicine and Forensic Science of Valencia, Alicante and Castellon, and that has included the closing of every case. In those cases, in which it was considered necessary, the study was completed in the Unit of Evaluation of Risk of Sudden Familiar Death. The clinical, epidemiological and inherited cardiopathies were centralized in the Division of Neonatology, and Cardiology of the University and Polytechnic Hospital La Fe, and studies related with the legal autopsy, medical-legal procedures and closing of the cases in the Institute of Legal Medicine and Forensic Sciences of Valencia. To investigate the level of acquaintance with SIDS risk and protective factors of the general population, we undertook a prospective, observational and descriptive study in the Maternity Ward of the University and Polytechnic Hospital La Fe during the months of December 2019 and January 2020 using an anonymized survey pre-and-post formative intervention during their hospital stay after birth and right before hospital discharge. Results A total of 132 infants dead at less of one year of age were analyzed. In 56 cases (42%), an explanatory cause for death was found, and not in 76 infants (58%). The latter were included in the group of SIDS and the former in the group of Explained Sudden Infant Death Syndrome (ESIDS). Males were predominant in both groups. Age was significantly lower in the group of SIDS with a median of 3 months as compared to 4 months in the ESIDS group. Almost all cases of SIDS occurred during sleep time and predominantly in the colder months. The incidence of SIDS in the Community of Valencia, with a median rate of mortality of 0,14 per 1000 live births, has a mean of 0,24 per 1000 live births. We didn’t find familiar background of any mild condition before SIDS in 99% of the cases while it was of 78% in ESIDS (p<001). No significant differences between both groups in relation to the presence of familiar background of sudden death, abortions, hospital delivery, type of delivery or chorioamnionitis. A total of 75% of the deceased infants in the SIDS group were sleeping in an insecure environment versus 38,5% in the ESIDS group (0.002). A total of 97% of the infants of the SIDS group died during sleep versus 59% in the ESIDS group (p<0.001). 47% of the infants of the SIDS group were in prone position while only 5,4% in the ESIDS group (p<0.001). 49% of the infants in the SIDS group reported co-sleeping versus 25% in the ESIDS group (p=0.01). Analyzing risk factors for death, infants practicing co-sleeping face a significantly greater risk of unexplained death, and an age at death significantly lower as compared to those that didn’t practice co-sleeping. Toxic ingestion during pregnancy (tobacco, alcohol, ilegal drugs) was significantly higher in the SIDS group tan in the ESIDS group although not statistically significant. In relation to co-sleeping and breastfeeding (BF), the percentage of babies fed with BF exclusively was slightly higher than formula fed in the SIDS group as compared to the ESIDS group, although not statistically significant (p = 0.66). Judicial lifting of the body was performed in 69% of cases in the SIDS group, while only in 47% (p=0.046) of the corpses in the ESIDS group. A 49% of the infants in the SIDS group died at home and 26,5% in the ESIDS group. Cardiorespiratory resuscitation maneuvers were performed in 95,5% in the ESIDS group and 87% in the SIDS group. Cooling during judicial lifting was significantly higher (P=0.008) in the SIDS group. Prone position was significantly more frequent in the SIDS group compared to the ESIDS group (p=0.002). Histologic and microbiologic infection findings were significantly higher in the ESIDS group as compared to the SIDS group (p=0.01). Toxicological analysis rendered positive in 6 cases of SIDS and 1 of ESIDS. Alveolar bleeding in the histologic examination of the lung revealed a significant difference (p=0.03) in favor of the unsecure sleep as compared to the secure sleep group. Similar findings were evident for congestion and severe congestion with renal bleeding (p=0.03). According to the San Diego Classification, in the ESIDS group, 81% pertained to the Category II, 7% to the Category IB, 12% to the indetermined and no cases were classified as Category IA. The most frequent finding in the ESIDS group were infectious conditions, found in 51% of the cases followed by cardiac conditions in 35% and malformations in 14%. A total of 36 index cases and 94 family members were studies under the suspicion of channelopathies or potential inheritable cardiac conditions. A total of 15 genetic studies were performed and in 4 cases objective genetic alterations were detected which represents 26% of the cases studied. In relation to the degree of information related to the risk and protective factors for SIDS, the mean scoring for correct responses was 5,08 (± 2,9) for the pre-intervention period and 6,10 (± 2,5) for the post-intervention period representing a statistically significant difference (p <0,001) Conclusions 1. Mortality rate for SIDS is of 0,24 per 1000 live births. 2. Male sex is predominant. The highest incidence occurs bewteen 1 and 3 months of age. The great majority of cases of SIDS occur in the coldest months. 3. In the secure sleeping environment, prone position, co-sleeping and overheating have rendered as risk factors for SIDS. There is a higher risk of dying of SIDS for babies who practice co-sleeping or in prone position. 4. SIDS is a multifactorial and complex entity. Its study requires a multidisciplinary team that includes forensic doctors, pathologists, pediatricians, cardiologists, geneticists, microbiologists, and other specialists that contribute to provide with key information that allow to establish the categories that are followed in San Diego’s Classification, confirm risk factors that permit the design of preventive strategies and direct the cardiological studies that includes parents and family for genetic counseling before future gestations take place. 5. Mothers, fathrs and family members of newborn infants have a low level of knowledge for the prevention of SIDS. It is necessary to promote informative population campaigns, and formative campaigns for mothers, fathers and family members especially along gestation and during the neonatal period. Risk and protective factors should also be spread out among health care givers.