Assisted reproductive technology has been used in clinic for many years, IVF-ET technology is also known as the "last hope" of many infertile couples. Missed abortion as an important factor to reduce the success rate of pregnancy brings the sense of frustration and disappointment to patients. Only clarifying the clinical influencing factors of missed abortion after IVF-ET can we provide a basis for etiological treatment. In this study, 8 independent influencing factors were discovered.
Our study found that there was abnormal coagulation function in people with missed abortion, such as the shortening of APTT and PT, suggesting the hypercoagulable state of blood. The possible reason is that the hypercoagulable state of blood can selectively affect the blood circulation of uterus and placenta, form microthrombus in the placenta, cause local placental infarction, decrease of placental blood supply, embryo or fetal ischemia and hypoxia, leading to embryo grow arrest[17].
The hypothalamus-pituitary-ovary axis regulates the complex endocrine system of the body. When any part of the axis is abnormal, it can lead to adverse pregnancy outcome. In this study, it was found that the level of PRL was also significantly increased in the observation group, and hyperprolactinemia was common in pituitary dysfunction or pituitary space occupying lesions. Increased prolactin can inhibit the synthesis and release of gonadotropin, affect the development of follicles, cause ovulation disorders, and affect the development of embryos, resulting in infertility or missed abortion[18]. In addition, the level of AMH in the placenta group decreased and was often accompanied by structural lesions of the ovary. Some studies found that AMH was negatively correlated with the risk of early spontaneous abortion[19], and the structural changes of the ovary would affect its function. Progesterone is an important condition for successful implantation of fertilized eggs and pregnancy, and good ovarian function is an important condition for normal pregnancy[20].
Age has always played an important role in the success of pregnancy. With the increase of age, the quality of oocytes decreases, mainly manifested in the occurrence of errors in the process of oocyte meiosis, the formation of aneuploidy, chromosome translocation, inversion and so on. Embryos formed by such gametes are at greater risk of spontaneously stopping development[21,22]. Our study not only confirms the above point of view, but also finds that male age is also an important influencing factor. Some other studies have shown that the male sperm quality decreases with the increase of male age, and the probability of gene mutation increases[23,24]. In our study, sperm abnormality has no effect on the results, the possible reason is that the standard of abnormal sperm in is based on clinical diagnosis, such as oligospermia, asthenospermia and sperm deformity. Rather than the quality of sperm for in vitro fertilization in the laboratory. Recently, China's three-child policy has been implemented but the reproductive desire of young women has been decreasing. The proportion of advanced pregnant women in China will increase. So it is worth thinking about what policies should be adopted to encourage women to give birth at the appropriate age.
Another finding of our study is that the level of FT4 in people with embryo termination was lower than that in normal people, and the positive rate of TPO-Ab increased significantly, suggesting that thyroid dysfunction may have adverse effects on embryos. Previous studies have shown that hypothyroidism may cause adverse effects such as embryo termination and fetal malformations[25]. TPO-Ab and TG-Ab are specific indicators of thyroid autoimmunity. Abnormal levels of TPO-Ab and TG-Ab can cause autoimmune hypothyroidism. Some studies[26,27] have shown that positive TPO-Ab early pregnant women have a corresponding increased risk of abortion. Therefore, we should pay attention to pre-pregnancy thyroid function examination, and give reasonable treatment to women who are diagnosed with thyroid diseases and abnormal laboratory indexes.
The last influencing factor is immune factor. ACA and ANA are human autoimmune antibodies. This study found that these two antibodies showed an increasing trend in missed abortion people. It was found that ACA may act on the membrane phospholipids of placental vascular endothelial cells and platelets in the early stage of pregnancy, block prostacyclin synthesis, and lead to placental embolism. ANA may be related to its influence on DNA replication and immune abnormalities[28].
Synthesize the above factors, our study attempts to establish a XGBoost-based missed abortion risk prediction model in patients treated with IVF-ET, and found that its prediction performance is better than the traditional logical regression model. Machine learning is a new field of artificial intelligence, the XGBoost algorithm in this study belongs to the integrated tree algorithm, and the integrated tree algorithm is a popular algorithm in the field of machine learning in recent years. It may replace the classical logistic model to predict the risk of missed abortion, and take this as a theoretical basis to make targeted preventive measures. When predicting the risk of missed abortion, doctors should intervene the high-risk factors in advance and monitor these people in time after confirming clinical pregnancy to avoid missing diagnosis leading to long-term retention of embryos in the uterus.
Limitations
One of the limitations of this study is that the inclusion index does not reach an ideal state. Embryonic chromosomes, bad living habits, history of close contact with pets and environmental factors are not included, because this study is a retrospective study. there are some deficiencies in clinical data, and the subjective indicators are difficult to be standardized. If there is an opportunity to complete the inclusion of indicators in the future, a more accurate forecasting model may be constructed. Another limitation is that the research population has strong regional characteristics and does not have wide representativeness. It is hoped that the data from multiple medical centers can be used for the external verification of the model.