Trends of Twin Birth in Korea, 1991-2018

Abstract

pairs), provided by Statistics Korea. Weinberg's differential rule was used to estimate the number of MZ and DZ twin births. The impact of assisted reproductive technologies (ART) on MZ and DZ twinning was analyzed by examining data after the introduction of the national support program for infertile couples. The odds ratio (OR) and 95% confidence intervals were calculated to describe the trend in the MZ and DZ twinning ratio. Results: From 1991 to 2018, the DZ/MZ ratio increased significantly from 0.45 to 3.30. Prior to the introduction of the national support program for infertile couples (1991-1994 years), the DZ/MZ ratio was 0.54, but after its introduction, the DZ/MZ ratio was 1.

Familial Risk of Inflammatory Bowel Disease: A Population-Based Cohort Study in South Korea

“…Among twins, same-sex twins had a significantly higher risk compared with opposite-sex twins for both UC and CD (Supplementary Table 11). Although we do not have the breakdown of monozygotic to dizygotic twins, based on estimation for zygosity, 15 we can estimate that these same-sex twins had a higher ratio of monozygotic twins (Supplementary Methods and Supplementary Table 12).…”

Pregnancy outcomes in twin pregnancies over 10 years

“…The ratio of dizygotic to monozygotic twins also went up from 2.4 in 2006 to 2.97 in 2017 [7][8][9].…”

“…As a result, two or more gestational sacs were identified in 21.4% of pregnant women in 2017. The ratio of dizygotic to monozygotic twins also went up from 2.4 in 2006 to 2.97 in 2017 [ 7 – 9 ].…”

“…In Korea, ARTs were introduced in 1986, and the government has provided financial support for infertile couples since 2006 [ 6 ]. After the provision of government support, the twin birth rate sharply increased, by 7–10% per year [ 7 ]. Despite the increase, data on twin pregnancy outcomes in Korea are lacking.…”