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Recent decelerated decline in perinatal mortality rate of unlike‐sexed twins in Japan
Author(s) -
Kato Noriko
Publication year - 2004
Publication title -
paediatric and perinatal epidemiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.667
H-Index - 88
eISSN - 1365-3016
pISSN - 0269-5022
DOI - 10.1111/j.1365-3016.2004.00555.x
Subject(s) - medicine , perinatal mortality , demography , gestational age , obstetrics , infant mortality , mortality rate , pregnancy , fetus , population , biology , genetics , sociology , environmental health
Summary The effect of assisted reproductive technology is more pronounced in unlike‐sexed twins than in like‐sexed. Trends in perinatal mortality of twins were compared between the two types of sex combination. Certificates for births (478 276 cases), stillbirths (50 542 cases), and early neonatal deaths (8747 cases) were the subjects of this analysis. Since 1984, the decline in the perinatal mortality of unlike‐sexed twins has been slower than that of like‐sexed twins. In both light‐for‐dates (LFD) and non‐LFD, the decline in the gestational age standardised mortality ratio has been slower in unlike‐sexed twins. We suggest this is due to the introduction of assisted reproductive technologies.