Digestive system diseases during pregnancy

Hemostatic disorders and thrombophilia

Thrombophilia is a pathological predisposition to blood clot formation. During gestation, the risk of venous thrombosis physiologically increases 5–6 times due to the propensity for blood stasis and hypercoagulation. The presence of additional hemostatic defects multiplies the likelihood of vascular catastrophes.

There are two main groups of thrombophilias:

1. Acquired. The main representative is antiphospholipid syndrome (APS). This is an autoimmune condition in which circulating antibodies (lupus anticoagulant, antithrombin antibodies, etc.) damage the endothelium, suppress fibrinolysis, and activate platelets. The diagnosis is valid only when laboratory markers and clinical manifestations are combined.
2. Congenital (hereditary). Caused by genetic defects. Common causes include: Factor V Leiden mutation (impairs protein C function), prothrombin G20210A mutation (increases the risk of thrombosis 3-fold), and PAI-1 gene polymorphism. A separate category is the methylenetetrahydrofolate reductase gene mutation, which leads to an excess of homocysteine. It becomes oxidized, forms free radicals, and destroys the vascular wall.

Obstetric complications are directly related to microcirculation disorders. Defective trophoblast invasion and thrombosis of uteroplacental vessels lead to endothelial dysfunction. Clinically, this manifests as preeclampsia, chronic placental insufficiency, fetal hypoxia, recurrent pregnancy loss, and placental abruption.

Principles of antithrombotic therapy

To detect the threat of thrombosis, molecular markers of intravascular coagulation are investigated: D-dimer, thrombin-antithrombin complexes, F1+2 fragment, and fibrin degradation products.

The basis of prevention and treatment is low molecular weight heparins (LMWHs). Their main advantages are:

• Do not cross the placental barrier.
• Have a low risk of bleeding and heparin-induced thrombocytopenia.
• Convenient to use (one injection per day).

At high risk (presence of APS, genetic defects, or a history of thrombosis), anticoagulants are prescribed for the entire gestation period, starting from the planning stage (in the fertile cycle). The drugs are discontinued on the eve of delivery and resumed 6–8 hours after childbirth or surgery, continuing the course for 10–14 days.

Management of patients with epilepsy

Epilepsy occurs in 0.3–0.6% of pregnant women. Against the background of gestation, due to an increase in circulating blood volume, hypoproteinemia, and accelerated excretion, the plasma concentration of anticonvulsants drops. This can trigger an increased frequency of seizures.

The greatest threat to the mother is status epilepticus, which can cause severe brain and kidney damage due to hyperthermia and hypoxia. For the fetus, the main risks lie in the teratogenic effects of the drugs themselves and the concomitant folic acid deficiency (risk of neural tube defects, cleft palate, heart defects). Newborns may also develop a deficiency of vitamin K-dependent clotting factors, which is fraught with bleeding.

Management Strategy:

• There are no anticonvulsants that are absolutely safe for the fetus, but therapy must not be interrupted.
• A neurologist examination is required at least once a month for timely dose adjustments.
• Delivery is conducted via the natural birth canal with the mandatory continuation of medication.
• Cesarean section is indicated only in cases of status epilepticus or frequent relapses in late stages.
• Breastfeeding is permitted, but requires safety measures (feeding in a lying position).

Ophthalmological pathologies: focus on myopia

Eye diseases, in particular myopia, account for 18–19% of all extragenital pathologies in expectant mothers. During pregnancy, intraocular pressure physiologically decreases and blood circulation in the organ of vision worsens due to arteriolar spasm. The situation is sharply aggravated by the addition of preeclampsia, anemia, or diabetes mellitus.

Severe preeclampsia directly correlates with the severity of retinal angiopathy. The most formidable complications include hemorrhages, optic disc edema, and retinal detachment.

Patients with moderate and high myopia should be examined by an ophthalmologist in each trimester. If retinal tears are detected, barrier laser photocoagulation is indicated. If the fundus status is stable after such a procedure, vaginal delivery is not contraindicated. The final conclusion on the mode of delivery is formed at 36–37 weeks.

Briefly: answers to topical questions

Class and exam questions

What else to study on this topic

• Pathogenesis of antiphospholipid syndrome (APS) and the development of endotheliosis.
• The effect of hyperhomocysteinemia on the vascular wall and nitric oxide.
• Criteria for the effectiveness of antithrombotic therapy (laboratory and clinical).
• Teratogenic action of anticonvulsants and mechanisms of folic acid deficiency.
• Indications and timing of retinal laser photocoagulation during gestation.

Other topics in the "Obstetrics" section

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.