Reproductive changes among women in their 40s: A cross-sectional study

Abstract

Introduction The aim was to describe and compare changes in the reproductive pattern of women in their 40s observed over a decade in Scandinavia.

Material and Methods Cross-sectional study using the total population of women aged 40–49 years between 2008–2018 in Denmark, Norway and Sweden (on average n = 1.5 million). Aggregated data concerning birth and induced abortion rate were collected and analyzed from national health registers. National data on redeemed prescriptions of hormonal contraceptives in the three countries were collected from prescription registers. Births after spontaneous and assisted conceptions were identified by using cross-linked data on deliveries from the Medical Birth Registers and National Registers of Assisted Reproduction in the three countries.

Results Use of hormonal contraception increased among women aged 40–44 years in Denmark from 24% to 31%, in Sweden from 27% to 30%, and in Norway from 22% to 24%. The levonorgestrel-releasing intrauterine device was the most frequently used method in all countries. Birth rates among women 40–44 years increased continuously from 9.5 to 12/1000 women in Denmark and from 11.7 to 14.3/1000 in Sweden, but remained stable in Norway at ~11/1000 women. There was a doubling of assisted conceptions in Denmark from 0.71 to 1.71/1000 women, Sweden from 0.43 to 0.81/1000 and Norway from 0.25 to 0.53/1000 women 40–49 years of age. Sweden had the highest induced abortion rate (7.7 to 8.1/1000 women) in women aged 40–49 years during the study period.

Conclusions From 2008 to 2018, birth rates continuously increased among women aged 40–49 years in Denmark and Sweden and births resulting from assisted reproductive technology doubled in all three countries.