Abstract:

Objective To discuss the pregnancy outcomes of the patients with different body mass index （BMI） underwent fresh embryo transfer cycles and frozen-thawed embryo transfer （FET） cycles after treated with long regimen controlled ovarian hyperstimulation （COH）， and to analyze the correlation between BMI and the pregnancy outcomes after treated with assisted reproductive technology （ART）. Methods The patients who underwent long regimen COH were divided into fresh embryo transfer cycle group （n=1 957） and FET cycle group （n=2 328）， according to their BMI， the patients in both groups were further classified into lean group（BMI <18.5 kg·m^－2）， normal group（18.5 kg·m^－2 ≤BMI <24.0 kg·m^－2）， overweight group（24.0 kg·m^－2 ≤BMI <28.0 kg·m^－2）， and obese group（BMI≥28.0 kg·m^－2）.The general informations， COH conditions， embryo conditions and clinical pregnancy outcomes of the patients in various groups were collected and analyzed. Results There were 1 957 patients， 1 957 cycles in fresh embryo transfer cycle group， which included 103 cycles in lean group， 1 254 cycles in normal group， 476 cycles in overweight group and 124 cycles in obese group. Compared with normal group， the levels of basal follicle-stimulating hormone （bFSH）， basal estradiol （bE2） and basal luteinizing hormone （bLH） of the patients in lean group were significantly increased （P<0.01）； the age of the patients in overweight group was increased （P<0.05）， the levels of bFSH， bE2， basal progesterone （bP） and bLH of the patients in overweight group were significantly decreased （P<0.01）； the levels of bFSH， bE2， and bLH of the patients in obese group were significantly decreased （P<0.01）， while the infertility time and basal testosterone （bT） level were significantly increased （P<0.05 or P<0.01）. Compared with lean group， the use time of gonadotropins（Gn） of the patients in overweight group was significantly increased （P<0.01）， the fertilization rates and transferrable embryo rates of the patients in normal， overweight and obese groups were decreased （P<0.01）. In FET cycle group， there were 1 914 patients， 2 328 cycles， including 128 cycles in lean group， 1 503 cycles in normal group， 557 cycles in overweight group and 140 cycles in obese group. Compared with lean group， the ages of patients in normal， overweight and obese groups were significantly increased （P<0.05 or P<0.01）. Conclusion For the infertile patients who are going to undergo the in vitro fertilization （IVF）， maintaining normal body weight could reduce the dosage of ovulation induction drugs， obtain more embryos， and offer more chances of pregnancy.

Key words: Body mass index, Long regimen, Fresh embryo transfer, Freeze thaw embryo transfer, Pregnancy outcome