ملخص
Abstract Background: The growing trend of delaying pregnancy creates new challenges for obstetric care, as older mothers have an increased risk of obstetric complications and perinatal morbidity and mortality. Quantitative histological studies of the placenta will be of clinical significance as well as advance the knowledge about the placental function and help to reveal the causes of these complications. Study design: A case-control study was conducted between June 2018 and April 2019 at the Department of Histology and Genetics, Faculty of Medicine, University of Tripoli and the Department of Obstetrics and Gynaecology, Ali Omer Asker hospital, Libya. Aim of the study: This study was carried out to evaluate the microscopic structure of the full-term human placenta and neonatal outcome in relation to advanced maternal age. (AMA). Materials and Methods: A total of 40 full-term human placentae of primiparous healthy Libyan women were obtained from the Department of Obstetrics and Gynaecology in Ali Omer Asker hospital. The placentae were divided into two groups; the control group (30 placentae from pregnant women of age between 20 and 35 years) and the study group (10 placentae from pregnant women 35 years of age and older). Whole-thickness placental section of size 1cm × 1cm was taken from the central part of each placenta and after proper fixation in 10% neutral buffered formalin, the tissues were dehydrated in ascending graduated concentrations of alcohol 50%, 70%, 80%, 96%, and 100%, followed by clearing in xylene and embedding in paraffin. Five-micron serial sections were generated with the help of a rotator microtome. The tissue sections were stained with hematoxylin and eosin stain and Mallory’s trichrome then were examined for morphological changes. Furthermore, a quantitative analysis of placental parenchyma (fetal blood capillaries, intervillous space, collagen, and syncytiotrophoblast) was done using Leica Quantitative Image Analysis System. Results: The median age of mothers was 25?years with an Inter Quartile Range of (23–35.5). There was an increasing demand for assisted reproductive techniques with increasing age. Women at AMA had a higher risk for caesarean section. In addition, there was no significant difference in neonatal birth weight, Appearance; Pulse; Grimace; Activity; Respiration (APGAR) score at the 5 th minute, Neonatal Intensive Care Unit (NICU) admission rate, and placental weight between the two study groups (P>0.05). However, the placental weight/birthweight ratio in elderly mothers was significantly higher with respect to younger mothers (P=0.021). The histomorphometry study showed a highly significant reduction (P=0.009) in the lumen area of fetal blood capillaries in mothers at AMA compared to the control group. The area of intervillous space of placentae in older pregnant women compared to younger ones was significantly increased (P=0.003) while the syncytiotrophoblast thickness and collagen expressed in chorionic villi of two examined groups of pregnant women were not significantly different (P>0.05). Conclusion: AMA was associated with histological changes in the full-term human placenta and these changes explain the capability of older pregnant women’s placenta to induce compensational mechanisms, whose main role is maintaining normal fetal growth and development.