Causes of intrauterine arrest

Intrauterine developmental arrest is unfortunate news for any mother and family. Intrauterine developmental arrest literally means that the embryo stops developing in the uterus. I believe everyone understands what this means. Although intrauterine growth arrest is not common in clinical medicine, it does not mean that it will not happen. The main causes of intrauterine growth arrest are chromosomal reasons, uterine abnormalities and reproductive infections. If the pregnancy cannot be saved, the intrauterine growth arrest will eventually tend to result in spontaneous abortion.

1. Chromosomal abnormalities

Chromosome abnormalities are generally divided into quantitative abnormalities and structural abnormalities; quantitative abnormalities include polyploidy and aneuploidy, among which the most common abnormal karyotype is aneuploidy triploidy. Many triploidies are often lethal, and most of them are bound to result in miscarriage. Haploidy and tetraploidy can also cause the embryo to stop developing.

Common structural abnormalities include balanced chromosomal translocations. Regardless of which spouse has a balanced chromosomal translocation, duplication or loss of chromosomal fragments may occur when the embryo forms chromosome fusion. This abnormality may cause the embryo to stop developing.

2. Uterine abnormalities

The uterus is like the land that nurtures the embryo. When the fertilized egg reaches the uterine cavity and begins to grow and develop, the internal environment of the uterus and the overall environment of the uterus may affect the embryo.

The internal environment is the endometrium. If it is too thin or too thick, it will affect implantation. Congenital abnormalities in the uterine morphology and development, such as unicornuate uterus, bicornuate uterus, didelphic uterus and septate uterus, etc., may cause the embryo to be unable to implant and develop normally due to the narrow uterine cavity and insufficient blood supply caused by the abnormal morphology.

Insufficient overall uterine space is also not good. Uterine adhesions will cause the uterine cavity to become smaller, making it impossible to provide sufficient development space for the embryo, thereby affecting embryonic growth and placental implantation, and ultimately leading to fetal arrest. Uterine fibroids and endometriosis may also cause insufficient blood supply to the embryo and abnormal implantation. Some fibroids may also cause hormonal changes, which can also cause the embryo to stop developing.

3. Endocrine disorders

The implantation and continued development of the embryo depend on the coordination of a complex endocrine system. Any abnormality in any link may lead to fetal growth retardation.

Three important hormones are needed during the early development of the embryo: progesterone, estrogen and human chorionic gonadotropin. If the mother does not produce enough hormones to meet the needs of the embryo, it may cause fetal arrest and miscarriage. The most common cause is luteal dysfunction. Due to luteal insufficiency, the luteal phase will be shortened and the endometrium will develop slowly, thus affecting the implantation of the fertilized egg or early pregnancy miscarriage. Luteal insufficiency may also be accompanied by other glandular dysfunctions, such as hyperthyroidism or diabetes, hyperprolactinemia and hyperandrogenism, etc. These factors are not conducive to embryonic development.

4. Reproductive tract infection

Severe TORCH infection in early pregnancy can cause fetal death, while milder infection may cause fetal malformation. For example, cytomegalovirus. After the mother is infected, the pathogen can infect the placenta through the blood, causing damage to the chorionic and capillary endothelium, destroying the placental barrier. The pathogen enters the fetus and causes miscarriage, embryonic development cessation, and fetal malformations.