Background: Due to the choice of postponing motherhood, the average age of women giving birth in Poland has moved into older age groups. This study was conducted to assess pregnancy complications and birth outcomes in women of advanced maternal age (AMA, over 35 years of age) compared with women aged 35 years. Material and Methods: Data on births was obtained from two third-degree hospitals in Warsaw, Poland for the years 2017 – 2019. Maternal and perinatal outcomes for women of advanced maternal age (n = 3,766) were analyzed using Chi-square tests and the ANOVA Kruskal-Wallis test. Comparisons between the following age groups of women were conducted: age 35 (control group), 36 – 39, 40 – 44 and over 45 years of age. Results of the analysis are presented with unadjusted odds ratios, 95 percent confidence intervals and p-values. Results: The incidence of pregnancy-induced hypertension (PIH) was found to increase with age in the 36 – 39 (OR 1.76, CI 1.09 – 2.87), 40 – 44 (OR 2.72, CI 1.56 – 4.73) and in the over 45 (OR 6.34, CI 2.04 – 19.69) age groups. The risk of gestational diabetes was seen to increase in women aged 40 – 44 (OR 1.49, CI 1.13 – 1.97) and increases almost three times in women over the age of 45 (OR 2.88, CI 1.41 – 5.87). The frequency of births by Cesarean section was observed to increase by one quarter in the 36 – 39 age group (OR 1.26, CI 1.07 – 1.48), by half in the 40 – 44 age group (OR 1.5, CI 1.28 – 1.96) and almost three times in women over 45 (OR 2.88, CI 1.41 – 5.87). There was no statistical significance for the incidence of preterm delivery, induction of labor and postpartum anemia or the health status of newborns in the studied age groups. Conclusions: Maternal age of over 35 years old is an independent risk factor for higher rates of pregnancy and perinatal complications in the Polish population.
