Introduction. Pregnancy in women of extreme ages has become a global problem. The notion of extreme age unites in itself, two great periods in a woman's life, adolescence and old age. According to the World Health Organization, a teenage pregnancy is defined as a pregnancy that occurs in girls aged between 10 and 19 years old. Each year, an estimated 21 million girls aged 15-19 years in developing countries become pregnant and about 12 million of them give birth, and 777,000 births occur to adolescent girls younger than 15 years. Over the last 30 years, although the birth rate has been decreasing considerably, the age at which women become pregnant has gradually increased, the fertility rate in European countries being 51.0 births per 1,000 women, Italy being in first place. In today's modern society, many women postpone pregnancy to an older age for various reasons, such as late marriage, longer life expectancy, the use of modern methods of contraception, and modern infertility treatment. Both teenage pregnancy and pregnancy in old age establish associations with a number of unfavorable outcomes and complications, such as anemia, poor nutritional status, preeclampsia, labor and premature birth, sexually transmitted infections, urinary tract infections, higher rate of assisted birth, as well as placental dysfunction, perinatal mortality, hypertensive disease, gestational diabetes, placenta praevia and abruptio placentae. Aim of the study. Research the particularities of the evolution of pregnancy and birth in primiparous women up to 19 years of age and after 35 years. Materials and methods. The study was conducted during 2018 and 2019, on a sample of 130 medical records in the Clinical Municipal Hospital No.1 Chisinau, Republic of Moldova. The research study presented is a descriptive, retrospective one. The patients included in the study were divided into two groups: Group I - 62 patients aged ≤19 years; Group II - 68 patients ≥35 years of age. Results. Following the research carried out, in pregnant women the most frequently determined extragenital pathologies were diseases of the CV system (11.76±0.42%) and of the CNS (10.29 ± 0.21%), while in adolescents reported more frequently anemia (33.87±0.33%) and diseases of the urinary system (24.19 ± 0.38%) (p <0.001). In the group I of pregnant women, the obstetrical and gynecological history was complicated by: irregular menstrual cycle (35.4±0.66%), PID (12.90± 0.21%) and TORCH infections (9.68±0,26%), and in pregnant women of the group II - late menarche (17.65±0.50%) and uterine myoma (11.76±0.21%) (p <0.001). The results of the study revealed that pregnancy in pregnant women in group I was conceived naturally in 100% of cases, while in research group II - only in 76.47±1.21% of cases (p <0.05 ), and in 23.53±0.16% of cases, the pregnancy occurred through IVF. We also determined a discrepancy in the data when analyzing the mode of birth, so the primiparous adolescents gave birth naturally in 83.87±2.38% of cases, compared to those of advanced age, in which vaginal birth occurred only in 51.47±0.92% of cases, and in 48.53±0.62% of cases, by C-section (p <0.05), the main indications being cephalopelvic disproportion, dynamic dystocia, acute fetal hypoxia and IVF. Conclusions. Following our research, we determined that maternal age is a major factor in the occurrence of pregnancy in women, having consequences on fertility with the onset of aging. We also noticed that in primiparous women with extreme ages, extragenital history complicated by (CV diseases, CNS diseases, anemia, urinary tract infections) and obstetrical and gynecological history complicated by (irregular menstrual cycle, TORCH-infections, late menarche, uterine myoma) have become important determinants in the evolution of pregnancy and childbirth. The results of the study revealed that maternal age is a risk factor for intrauterine development and the condition of the newborn at birth, as well as for the occurrence of maternal and fetal complications. In particular, adolescent age is associated with low birth weight of the fetus and advanced maternal age is associated with macrosomia (≥3999 g), thus increasing the incidence of shoulder dystocia, fetal trauma, such as cephalohematoma and clavicle fracture.