Abstract
Introduction In recent decades, there has been a continuous rise in the average age at which women
give birth. A maternal age of 35 years and above is considered an independent risk
factor in pregnancy and birth, due to higher rates of intervention. This study investigates
the influence of maternal age on birth procedure, gestational age, and rate of interventions
during delivery. The influence of maternal parity is also analyzed.
Material and Methods Data from the Austrian Register of Births was retrospectively collected and evaluated.
The collected data was the data of all singleton live births in Austria between January
1, 2008 and December 31, 2016 (n = 686 272). Multiple births and stillbirths were
excluded from the study. Maternal age and parity were analyzed in relation to predefined
variables (birth procedure, gestational age, episiotomy in cases of vaginal delivery,
epidural anesthesia in both vaginal and cesarean deliveries, and intrapartum micro-blood
gas analysis). Statistical data was evaluated using (1) descriptive univariate analysis,
(2) bivariate analysis, and (3) multinomial regression models.
Results The cesarean section rate and the rate of surgically-assisted vaginal deliveries
increased with advancing maternal age, especially in primiparous women, while the
rate of spontaneous deliveries decreased with increasing maternal age. A parity of
≥ 2 had a protective effect on the cesarean section rate. The rate of premature births
also increased with increasing maternal age, particularly among primiparous women.
Discussion Although higher maternal age has a negative effect on various obstetric parameters,
it was nevertheless not possible to identify a causal connection. Maternal age should
not be assessed as an independent risk factor; other factors such as lifestyle or
prior chronic disease and parity must be taken into consideration.
Key words
maternal age - obstetric outcome - advanced maternal age - high-risk pregnancy - parity
