Obstetrics Simplified - Diaa M. EI-Mowafi

Infectious Diseases in Pregnancy

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SYPHILIS

Effect of Syphilis on Pregnancy

The more is the duration between infection and conception, the less is the foetal affection.

• Abortion: of a dead foetus after the 4th month of pregnancy when the spirochetes can cross the placenta as the cytotrophoblast starts to disappear.
• Repeated late abortions then premature or mature macerated still born then live born with congenital syphilis or developing it later on.

Effect of Pregnancy on Syphilis

Primary lesion which is the sign of early syphilis may be masked if infection occurs during pregnancy.

Diagnosis

• History: of infection, repeated late abortions or macerated still birth.
• Examination: Signs of primary, secondary or tertiary syphilis.
• Investigations: by serological tests;
  • Non- specific (non-treponemal) tests:
    • Venereal disease research laboratory (VDRL).
    • Rapid plasma reagin (RPR).
  • Specific (treponemal) tests:
    • Fluorescent treponemal antibody absorption test (FTA - ABS).
    • Treponema pallidum immobilisation test (TPI).
  • Non-treponemal test can be positive in other conditions as collagen diseases , lymphomas, mononucleosis, and febrile illnesses. So these tests can be performed as screening tests, if positive a specific (treponemal) test is done to confirm or refute syphilis.

Evidence of syphilis in products of conception

• Placenta: is bulky with hypertrophied villi and endartritis of their vessels. Spirochetes may be detected in the villous stroma. These changes are detected in still born only.
• Umbilical cord: shows endarteritis, chronic cellular infiltration and sometimes spirochetes. These changes are detected in all cases.
• Foetus:
  • Stillborn: is macerated with syphilitic epiphysitis and hepatosplenomegaly in which spirochetes may be detected
  • Live birth: small - for -date with saddle nose, skin rash, hepatosplenomegaly, jaundice, osteochondritis and positive serological tests for syphilis.

Treatment

Mother

Treatment should be started before 16 weeks i.e. before spirochetes cross the placenta.

• Penicillin:
  • Procaine penicillin 600.000 units IM daily for 17 days or - benzathine penicilin (long acting) 2.4 million units IM, half the dose in each buttock. This is repeated for 3 courses at 2 weeks interval.
• (Erythromycin:
  • 500 mg/ 6 hours orally for 21 days is given to patients who are allergic to penicillin.

New born

Procaine penicillin 150.000 units IM for 10 days.

PULMONARY TUBERCULOSIS WITH PREGNANCY

Effect of T.B. on Pregnancy

• Abortion or premature labour rarely occur in acute febrile cases.
• The infant is usually not affected as it is extremely rare for tubercle bacilli to cross the placenta.

Effect of Pregnancy on T.B.

No effect on the course of the disease.

Diagnosis

Suggesting symptoms.

• X-ray chest after shielding the uterus from irradiation.
• Bacteriological examination for the sputum.

Management

Antenatal care

• Chemotherapy: isoniazid 300 mg orally and ethambutol 15mg/ kg orally for 9 months.
• Induction of abortion: active disease itself is not an indication for termination of pregnancy, but if there is gross respiratory impairment or the patient cannot tolerate the drugs because of excessive vomiting it may be indicated.

Labour

• Isolate the patient with active disease,
• give oxygen,
• avoid inhalation anaesthesia,
• shorten the second stage,
• avoid excessive blood loss.

Neonate

• Breast feeding is contraindicated only for the infants of patients with active disease who should be isolated.
• Neonate should be given isoniazid and vaccinated with isoniazid-resistant BCG and returned to his mother when he/she is tuberculin positive (2-10 weeks).

RUBELLA

Causative Organism: Rubella virus.

Route of Infection: via respiration as the virus is concentrated in the nasopharyngeal secretions.

Incubation Period: 14-21 days.

Clinical Manifestations

• Mild pyrexia,
• arthralgia,
• rash which persists for a week and always affecting the face,
• lymphadenopathy in the postauricular, deep cervical and suboccipital L.N. precedes the appearance of the rash and persists for 3 weeks.

Diagnosis

A pregnant woman who had been in contact with a case of rubella should have repeated estimations of rubella antibody titre. If antibodies are detected after being absent or rising, this indicates recent infection even in absence of clinical manifestations.

Complications

Abortion, still birth and low birth weight may occur.

Congenital anomalies include:

• cataract,
• deafness,
• cardiac anomalies,
• hepatosplenomegaly,
• lymphadenopathy.

Management

Prophylactic

Vaccination to all young females. Pregnancy should be avoided for 3 months after vaccination.

Induction of abortion

It is indicated if infection is caught in the first 12 weeks of pregnancy.

Viral Infections During Pregnancy

TOXOPLASMOSIS

Causative Parasite: Toxoplasma gondii.

Method of Transmission: It is believed to be cats faeces and uncooked meat or by transfer across the placenta.

Clinical Features: usually asymptomatic although fever, muscle pain and lympadenopathy may occur.

Complications

They occur only if there is acute exacerbation during pregnancy. This may lead to abortion or a live birth with the following manifestations which may develop weeks or months after birth:

• Convulsions,
• intracranial calcification,
• chorioretinitis,
• hydrocephalus or microcephaly,
• hepatosplenomegaly,
• jaundice and
• anaemia.

Diagnosis

Detection of specific IgM.

Treatment

Spiramycin 3 gm/day for 3-4 weeks.

MALARIA

Causative Parasite: Plasmodium: falciparum, vivax, ovale or malariae.

Complications

• Maternal haemolytic anaemia,
• abortion,
• preterm labour,
• intrauterine growth retardation,
• intrauterine foetal death.

Treatment

• Chloroquine is the drug of choice.
• Pyrimethamine + extra folic acid may be used in resistant P. falciparum.