Pregnancy stretch marks are specific atrophic skin changes caused by the destruction of connective tissue under the influence of gestation factors. They have the appearance of soft bluish-purple stripes located parallel or radially on the skin of the chest, abdomen. They are diagnosed during the examination, if necessary, the level of hormones in the blood and the histological structure of the biopsy from the defect area are examined. Effective treatment in pregnancy is not offered. The leading one is prevention with diet correction, the appointment of multivitamin complexes, reducing the load on the skin, improving microcirculation processes.
ICD 10
L90.6 Atrophic stripes (striae)
General information
Stretch marks (striae, linear skin atrophy, striated atrophoderma) occur during pregnancy in 50-90% of patients. Such atrophic changes are classified as secondary physiological. Although references to stretch marks of pregnant women are found in ancient Egyptian papyri, stripe-like atrophy was first described in detail in the XVIII century by the famous German anatomist, professor of midwifery Johann Roederer. Subsequent studies by dermatologists Ferdinand Gebra and Moritz Kaposi confirmed that changes at the level of the deep layers of the skin and subcutaneous tissue play a leading role in the development of the disorder. Currently, specialists in the field of gynecology consider pregnancy striae not as a disease, but as a cosmetic defect.
Causes
The etiology of the occurrence of pregnancy stretch marks has not been definitively established. Presumably, the reason for their formation is an increased load on inherently untenable connective tissue fibers. The defect is significantly more often detected in the presence of anamnestic data on the appearance of gestational stretch marks in relatives of a pregnant woman. A prerequisite for the formation of striae may be subclinical forms of connective tissue dysplasia caused by a violation of collagen synthesis, its excessive degradation, a change in the ratio between different collagens with a predominance of less durable fibers of types III-IV, similar elastin anomalies. During pregnancy, there are additional factors contributing to the formation of stretch marks:
- Hormonal restructuring. By the end of the gestational period, the cortisol level increases physiologically from 200-230 to 850-1140 nmol/l. Being a glucocorticoid, the hormone inhibits the proliferation of fibroblasts and their secretion of collagen fibers. Progesterone has a similar, albeit less pronounced effect, the content of which increases by more than 10 times by the 34-40 weeks of pregnancy. With an increase in the concentration of estrogen in the skin cells, the amount of amino acids necessary for the synthesis of collagen and elastin decreases.
- Mechanical stretching of the skin. Stretch marks appear more often on the abdomen and chest. Fetal growth contributes to an increase in the circumference of the abdomen. This indicator changes especially noticeably from 16-18 weeks of gestational age. Under the pressure of the growing uterus, the skin of the abdomen is excessively stretched, which is accompanied by the rupture of weakened connective tissue fibers. The likelihood of striae increases with polyhydramnios and multiple births. The increase in breast volume is associated with the development of alveolar tissue, and after childbirth — with the lactation process.
Excess weight during pregnancy plays a certain role in the formation of pregnancy stretch marks. Obesity, in which the volume of subcutaneous fat increases, contributes to stronger tension and damage to connective tissue fibers. In addition, adipose tissue is actively involved in the synthesis of estrogen, enhancing the effect of the hormone on the skin of a pregnant woman.
Pathogenesis
The mechanism of stretch marks formation during pregnancy is associated with an imbalance in the processes of synthesis and degradation of connective tissue fibers of the dermis. Under the influence of glucocorticosteroids and progestins, the synthesis of elastin and collagen by fibroblasts is inhibited, however, the ability of fibroblasts to produce collagenase and elastase is preserved. In conditions of relative amino acid deficiency caused by the estrogen effect, this weakens the mesh layer of the dermis. As a result, the strength and elasticity of the skin decreases, when it is mechanically stretched, collagen and elastin fibers are torn, defects are formed. Since the degradation products of fibrillar proteins have a fibrogenic effect, destruction is replaced by the processes of organization and sclerosis with the formation of scar tissue.
In the area of damage, a reaction resembling an inflammatory one occurs – the vessels are paretically expanded, around which lymphocytic infiltration begins. To replace the defect, fibroblasts produce connective tissue fibers, but their microarchitectonics is broken under stretching — collagen fibrils are arranged in bundles parallel to the epidermis, mixing with a large amount of immature elastin. Subsequently, the number of vessels and fibroblasts decreases in the stria area, and fibrous tissue prevails. In the center of the focus, elastin fibrils are almost completely absent, along the periphery they are arranged in the form of curls and dense lumps. The epidermis and dermis are thinning, which is typical for atrophy.
Symptoms
A characteristic sign of striated atrophoderma during gestation is the appearance of cyanotic—purple linear stripes on the abdominal wall, chest. Fresh striae are usually formed from the 25th week of pregnancy, although they may occur at earlier stages, especially with a sharp increase in the volume of the abdomen. Soft stripes run radially or parallel to each other level with the rest of the skin, much less often have a convex relief. The width of the stretch marks is usually from 1 to 5 mm, the length is from 0.8 to 10 cm. After pregnancy, as the damaged area ages, it gradually brightens, acquires a whitish, whitish-yellow, whitish-blue, mother-of-pearl hue. Stretch marks are not covered with a tan. Their relief eventually becomes drawn in (“sinking”). There are usually no subjective sensations in the uncomplicated course of linear skin atrophy.
Complications
Pregnancy stretch marks in the vast majority of cases do not pose any danger to the mother or fetus, although their appearance during pregnancy can serve as an impetus to the formation of an inferiority complex. In 0.41-0.83% of cases, the destruction of protein fibrils occurring during the formation of striae provokes an autoimmune response with the development of polymorphic dermatosis of pregnant women in the 3rd semester of gestation, accompanied by the appearance of itchy rash elements. A long-term consequence of stretch marks that have arisen during pregnancy is a persistent irreversible cosmetic defect that can cause neurosis, subdepression, obsessive states.
Diagnostics
With the formation of characteristic purple-cyanotic stripes on the skin of the chest and abdomen in the second half of pregnancy and the absence of other symptoms, diagnosis usually does not present any difficulties. A more thorough examination is required in cases where the presence of endocrine pathology or the onset of neoplastic processes can be suspected. The survey plan includes:
- Determination of hormone levels. Stretch marks are more often formed with an increased content of cortisol, ACTH, somatotropic hormone, a violation of the production of thyroxine and triiodothyronine. In some pregnant women, there is an excessive concentration of estradiol, progesterone in the blood.
- Examination of a skin biopsy. The deformation of elastin fibrils in the middle and deep layers of the dermis is characteristic: there are fragments of elastin, individual fibers are thickened, thinned, twisted, woven together. Infiltration of varying intensity is detected around the vessels.
If endocrine-active tumors are suspected, an additional study of the hypothalamic-pituitary region, thyroid gland, and adrenal glands is prescribed. Striated skin atrophy is differentiated with anethoderma, pathomimia, linear scleroderma, keloid scars, hypercorticism, Itsenko-Cushing’s disease, Marfan diencephalic syndrome, idiopathic Pasini-Pierini atrophoderma, Lawrence-Moon-Bardet-Bidl syndrome. Dermatologist, endocrinologist, neuropathologist, neurosurgeon, oncologist may be involved in the diagnostic search.
Prevention
Effective methods of treating fresh striae during gestation have not been proposed. The presence of stretch marks does not affect the choice of delivery method, pregnancy is usually completed by natural childbirth, when obstetric and extragenital contraindications are detected, a caesarean section is performed. The main efforts of an obstetrician-gynecologist and a pregnant woman are aimed at preventing the appearance of striae. Special attention is paid to women with burdened heredity, endocrine disorders, banded atrophoderma due to obesity or pubertal changes. To reduce the likelihood of stretch marks are recommended:
- Correction of the diet. Since during pregnancy one of the factors of striae formation is the relative deficiency of amino acids in the skin, the diet must be supplemented with protein products. It is important for predisposed patients to monitor the dynamics of weight gain, exclude overeating, and reduce the consumption of high-calorie carbohydrates and fats.
- Reception of vitamin and mineral complexes. For the prevention of stretch marks, supplements and medications containing tocopherol, retinol, ascorbic acid, vitamins of group B. The use of magnesium preparations can reduce the degradation of collagen, increase the strength of the dermis, weaken the processes of granularization of connective tissue.
- Reducing stress on the skin. To avoid overstretching of connective tissue fibers, it is recommended to perform exercises to strengthen the abdominal muscles, after the 18th-22nd week of pregnancy, wear a supportive bandage. To protect the mammary glands during gestation and breastfeeding, you should use a comfortable bra.
- Improvement of microcirculation in the skin. With a more intensive blood supply, the synthesis of protein fibrils increases, repair processes accelerate and normalize. To improve blood flow in the vessels of the skin, gentle massage of problem areas, contrast shower is used. Nourishing and moisturizing emollients have a definite, but not decisive effect.
Aesthetic cosmetology procedures that make stretch marks less noticeable are prescribed after the end of pregnancy. They are as effective as possible in the fight against fresh striae that exist no longer than 6 months. Mesotherapy, laser polishing, chemical peeling, electrophoresis or phonophoresis with collagen, hyaluronic acid, enzyme therapy, cosmeceuticals are most often used. With a significant change in the skin relief, it is possible to perform plastic surgery, contouring, injections of drugs based on hyaluronic acid.
