Additional file 3: of The risk of secondary sex ratio imbalance and increased monozygotic twinning after blastocyst transfer: data from the Japan Environment and Childrenâ s Study

Odds ratios of male infants by method of fertilization and parental characteristics. CT (early cleavage-stage embryo transfer), BT (blastocyst transfer), smoking and alcohol consumption habits at pregnancy recognition, SF-8 score of 50 or less. Low education: defined by the highest academic background and categorized as high school graduation or lower, Low income: defined by the annual revenue of the household and categorized as an annual income of 4,000,000 Japanese yen or less. (XLS 42 kb)本数据集统计了不同受精方式与父母特征下的男婴优势比。其中CT（early cleavage-stage embryo transfer，早期卵裂期胚胎移植）与BT（blastocyst transfer，囊胚移植）为所涉及的受精方式；分析变量涵盖妊娠确诊时的吸烟与饮酒习惯、SF-8量表得分≤50分的情况。低学历界定标准：以最高学历为依据，归类为高中毕业及以下；低收入界定标准：以家庭年收入为依据，归类为年收入400万日元及以下。（文件格式：XLS，大小：42 KB）