# Trend Analysis of the Sex Ratio at Birth in Greece

## TL;DR

This study tracks changes in the male-to-female birth ratio in Greece from 1956 to 2023, finding a significant decline in recent decades.

## Contribution

The study provides a comprehensive trend analysis of Greece's sex ratio at birth over a 68-year period using statistical regression methods.

## Key findings

- The overall sex ratio at birth in Greece from 1956 to 2023 was 1,068 male births per 1,000 female births.
- A statistically significant decline in the sex ratio occurred from 1982 to 2023, with an annual decrease of -0.297 male births per 1,000 female births.
- The lowest sex ratio in the period was recorded in 2023 at 1,051 male births per 1,000 female births.

## Abstract

Introduction: The sex ratio at birth, defined as the ratio of male to female live births, is a key indicator in the study of human reproduction and demographic patterns. This study aims to systematically examine the sex ratio in Greece and analyze its temporal trends over the period from 1956 to 2023.

Materials and methods: Data on the total number of live births in Greece, categorized by sex, were obtained from the Hellenic Statistical Authority based on birth certificate records. The sex ratio for each year was calculated as the number of male births per 1,000 female births. Trend analysis was conducted using joinpoint regression and supplemented with linear regression. The annual percent change (APC) and the beta coefficient were computed, along with 95% confidence intervals (95% CIs).

Results: Between 1956 and 2023, a total of 8,215,934 live births were recorded in Greece. The overall sex ratio at birth across all years was 1,068 male births per 1,000 female births, resulting in 269,468 excess male neonates. The gender ratio at birth ranged from a low of 1,047 in 1996 to a high of 1,085 in 2001. In all reported years, the sex ratio at birth was above 1,050, except for 1996. In the most recent year, 2023, the male-to-female ratio at birth was the second lowest of the entire period, at 1,051. Trend analysis revealed that the sex ratio at birth remained stable from 1956 to 1982 (p = 0.862) and showed a statistically significant downward trend from 1982 to 2023, with an annual percent change of -0.0274 (p = 0.004), or an average annual decrease of -0.297 (95% CI: -0.504 to -0.090, p = 0.006) male births per 1,000 female births.

Conclusions: The sex ratio at birth in Greece has significantly declined over the past four decades, reflecting similar trends observed in other developed nations. Further research is required to investigate the complex biological, demographic, and social factors influencing these trends, providing deeper insight into key aspects of human reproduction.