Spontaneous abortion in early pregnancy

Role of intrauterine infections (IUI)

In accordance with pathogenetic patterns, the effect of an infectious agent on the fetus strictly depends on the gestation age. Infection during blastogenesis and early embryogenesis leads either to fetal death and spontaneous abortion or to the formation of gross systemic malformations (teratogenic effect).

• Herpetic infection: When infected in early stages, a generalized process develops. The outcome is a spontaneous miscarriage or missed miscarriage.
• Congenital toxoplasmosis: Primary infection of the mother specifically in the 1st trimester poses the greatest danger (occurs in approximately 3 out of 1,000 pregnant women). The consequences for the fetus include spontaneous miscarriage, intrauterine fetal death, stillbirth, or the birth of a child with severe malformations.
• Congenital mycoplasmosis: In 25–50% of cases, it leads to malformations (hydrocephalus, microgyria), which also disrupts the normal course of early gestation stages.

Acute appendicitis: risks and obstetric management

Acute appendicitis can occur at any stage of pregnancy. It is important to remember the key rule: acute appendicitis (both uncomplicated and complicated) is not an indication for pregnancy termination regardless of the gestational age.

Nevertheless, the inflammatory disease itself and the subsequent surgical intervention (appendectomy) are major risk factors. They can become the direct cause of obstetric complications, including spontaneous miscarriage in early pregnancy and premature birth at later stages.

Differential diagnosis in the 1st trimester

In the first trimester, the clinical presentation of appendicitis is virtually indistinguishable from that in non-pregnant women. However, diagnosis is extremely difficult: classic symptoms (nausea, vomiting, lower abdominal pain) are often mistakenly regarded as early toxicosis or threatened spontaneous miscarriage.

To rule out the threat of abortion and confirm acute surgical pathology, reliable signs are used:

1. Elevated body temperature.
2. Coated tongue.
3. Local tenderness upon palpation in the right iliac region.

Specific diagnostically significant symptoms are also checked:

• Rovsing's sign: occurrence of pain in the right iliac region upon compression of the sigmoid colon and jerky movements from the left.
• Sitkovsky's sign: intensification of pain on the right side when the patient lies on her left side.
• Schottmüller's (Blumberg's) sign: classic sign of peritoneal irritation.

Laboratory verification in differential diagnosis

In the differential diagnosis between threatened miscarriage and an inflammatory process, it is important to correctly interpret blood tests. A single leukocyte count has only relative significance, as a physiological leukocytosis (up to $12 \times 10^9/\text{L}$) is characteristic of pregnant women.

Of greatest diagnostic value are:

• Assessment of leukocytosis over time (dynamically).
• Leukogram: a shift to the left (neutrophil shift) may be detected earlier than general leukocytosis.
• Comprehensive assessment: a combination of a pulse rate above 100 beats per minute with leukocytosis is compelling evidence in favor of appendicitis, even in the presence of a normal body temperature.

Diagnosis of infections triggering abortion

If an infectious nature of the spontaneous miscarriage is suspected (e.g., intrauterine herpetic infection), careful laboratory verification is required. The baseline diagnosis is established clinically and epidemiologically, but for precise confirmation, the following are used:

• Virological methods: culture method and electron microscopy of biological material.
• Cytological (morphological) studies: identification of a specific phenomenon — multinucleated giant cells with intranuclear inclusions.
• Serological tests: evaluation of rising antibody titers over time using the complement fixation test (CFT) and indirect hemagglutination assay (IHA).
• Highly informative modern methods: ELISA (enzyme-linked immunosorbent assay) and PCR (polymerase chain reaction).
• Rapid methods: DFA (direct fluorescent antibody) test for detecting viral particles in scrapings.

Generalized forms of infections are more likely to develop against the background of predisposing factors: the presence of HIV infection or prolonged immunosuppressive therapy (glucocorticosteroids, cytostatics).

Class and exam questions

What else to study on this topic

• Consequences of intrauterine infections in late pregnancy
• Ultrasonographic (US) signs of intrauterine fetal infection
• Clinical and diagnostic features of appendicitis in the 2nd and 3rd trimesters
• Clinical manifestations of chlamydial and cytomegalovirus infection in newborns
• Differential diagnosis of genital herpes and primary syphilis

Other topics in the "Additional Topics" section

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