The endometrium is the soil in which the embryo is planted and developed. A successful pregnancy cannot be achieved without a good embryo and the endometrium that receives the embryo, but we have found that a good egg or a good quality embryo does not necessarily guarantee a successful pregnancy, and after eliminating the cause of the seed, we need to consider the factor of the land, that is, the endometrium. Under normal circumstances, the uterine lining is thickened and shed periodically under the action of estrogen and progesterone, forming our menstrual cycle. During menstruation, the lining is shed, when it is at its thinnest, and as the follicle develops, the lining thickens with the secretion of estrogen. About 5 days after ovulation, the lining allows or is suitable for embryo implantation, half of which lasts for two or three days, which is also known as the “window period” for implantation. The thickness of the endometrium at this time varies from person to person, some people’s endometrium is always very thin, in the case of follicular development or even external medication can not make the endometrium thickening, which is called intractable endometrium, at present, there is no international standard for thin endometrium, most of the viewpoints are inclined to be less than 7mm. and if the maximum thickness of the endometrium is greater than 14mm, generally referred to as the endometrium is too thick. So, how does the thickness of the lining affect pregnancy? Thin endometrium Whether it is normal menstruation or successful embryo implantation can not be separated from fertile soil, research has found that less than 7mm endometrium pregnancy rate decreased significantly, just like the figure below, too thin endometrium in the formation of small hands (blood vessels) to grasp the endometrium will be very difficult, and may not be enough blood supply after the implantation of bed, so compared with the normal thickness of the endometrium, the thin endometrium implantation failure and early abortion will be more likely to occur. Therefore, thin endometrium is more likely to cause failure of conception and early miscarriage than normal endometrium. Thick endometrium: Does a thick endometrium affect embryo implantation? Some studies have found that 7-14mm is the optimal thickness of the endometrium for embryo implantation, and a thick endometrium can also affect pregnancy. So if your endometrium is found to be too thick, more than 14.mm or even 16mm before the transfer or during ovulation induction, you may be advised to give up the cycle, on one hand, because too thick endometrium may affect the blood supply to the endometrium, which will affect the embryo’s implantation, and on the other hand, the most important thing is to be alert to some benign and malignant endometrial lesions. Therefore, as the source of menstruation and the soil for embryo implantation, the thickness of the endometrium directly affects our menstruation and conception, and is an important sign of women’s health. Of course, these research data are only based on the majority of the population, too thin or too thick lining also have a chance of successful pregnancy, so do not be too nervous, listen to the doctor, take good care of, will certainly be able to get pregnant!