Blastocyst Transfer: A Risk Factor for Gestational Diabetes Mellitus in Women Undergoing In Vitro Fertilization

Background The risk of developing gestational diabetes mellitus (GDM) is higher in women undergoing assisted reproductive treatment than in women conceiving spontaneously. Objectives To determine whether the GDM risk after day-3 embryo transfer differs from the GDM risk after day-5 blastocyst transfer. Methods Prospective observational study in women becoming pregnant after first fresh embryo or blastocyst transfer. Results A total of 1579 women got pregnant and had live birth; 1300 women got day-3 embryo transfer only, whereas 279 women received at least 1 blastocyst. Of 1579 women, 252 developed GDM. Age, body mass index, baseline estradiol, baseline high-density lipoprotein, and progesterone on the day of human chorionic gonadotropin injection were not different in women receiving day-3 embryos only vs women receiving at least 1 blastocyst. The number and quality of retrieved oocytes were not different in women receiving day-3 embryo transfer from those receiving blastocysts. Our study confirmed already established GDM risk factors such as age and body mass index, baseline estradiol, and high-density lipoprotein, as well as progesterone after ovarian stimulation. We furthermore demonstrate that the GDM incidence in women receiving day-5 blastocyst transfer was significantly higher than those who received day-3 embryo transfer (21.15% vs 14.85%; P = 0.009). Considering confounding factors, we likewise saw that blastocyst transfer was an independent procedure-related GDM risk factor [P = 0.009, Exp (B): 1.56, 95% CI: 1.12-2.18]. Conclusion Blastocyst transfer after in vitro fertilization/intracytoplasmic sperm injection increases the risk of developing GDM.