Department of Reproductive and Perinatal Medicine, Hamamatsu University School of Medicine, Shizuoka, Japan.
Tawara IVF Clinic, Shizuoka, Japan.
PLoS One. 2023 Jun 23;18(6):e0287752. doi: 10.1371/journal.pone.0287752. eCollection 2023.
The sex of the conceived child is a significant concern for parents. To verify whether there women have pregnancy bias toward boys or girls, we investigated whether the history of continuous same-sex pregnancy was associated with the subsequent child's sex. We prospectively analyzed data from the Japan Environment and Children's Study, a birth cohort study. We included all cases of singleton live births (n = 98 412). Women with pregnancy due to infertility treatment were excluded (n = 6255); Similarly, women with a history of miscarriage, artificial abortion, stillbirth, and multiple pregnancies, and those with missing data on the sex of the previous child were excluded. Altogether, 62 718 women were included. For the first live birth, a male-biased sex ratio of 1.055 was observed. Further, no significant difference was found in the sex ratio of the conceived child between women with one boy and those with one girl previously. However, when there were more than two children previously, the subsequently conceived child's male/female sex ratio was significantly higher among boy-only mothers than among girl-only mothers. The results indicated that several pregnant women are biased toward conceiving either boys or girls.
孩子的性别是父母非常关注的问题。为了验证女性是否存在怀孕性别偏好，我们研究了连续怀同性别的妊娠史是否与随后孩子的性别有关。我们前瞻性地分析了日本环境与儿童研究（一项出生队列研究）的数据。我们纳入了所有单胎活产（n=98412）的病例。排除了因不孕治疗而怀孕的女性（n=6255）；同样，排除了有流产、人工流产、死产和多胎妊娠史以及之前孩子性别数据缺失的女性。总共纳入了 62718 名女性。对于第一胎活产，观察到男性偏性的性别比例为 1.055。此外，先前有一个男孩和一个女孩的女性所怀孩子的性别比例没有显著差异。然而，当之前有两个以上的孩子时，只有男孩的母亲随后所怀孩子的男/女性别比例明显高于只有女孩的母亲。结果表明，一些孕妇存在怀男孩或女孩的性别偏好。
