Infections in Pregnancy

1. Infections in Pregnancy Max Brinsmead PhD FRANZCOG April 2011

2. Syphilis • A sexually transmitted infection caused by the spirochaetal bacterium Treponemapallidum • Recognised in 3 stages in adults… • Primary = a painless genital ulcer with lymphadenopathy. May go unrecognised • Secondary = Fever, rash, anorexia, aches & pains. Occurs 2 – 8 weeks in only 1:3 individuals after primary infection and resolves spontaneously • Tertiary = can affect any body organ including heart, bones and brain

3. Diagnosis of Syphilis • Diagnosed by a serological test for reagin – a lipid released from cells that are attacked by T. pallidum • This test is sensitive and should revert to negative after treatment but… • It is not positive until up to 12w after infection • It is non-specific and there is a large number of conditions that cause a false positive test • Tests that detect antibodies to Treponema are more specific but… • They are present for life even after successful treatment • Yaws (and Pinta) will also be positive to these tests

4. Syphilis in Pregnancy • Typically does not cross the placenta until >20 weeks • Fetal effects include… • Stillbirth • Intrauterine growth restriction • Prematurity • Neonatal effects include… • Hepatosplenomegaly • Pneumonia • Anaemia & Jaundice • Skin lesions • Osteochondritis

5. Treatment of Syphilis • In the mother with a positive STS = serological test for syphilis • Give 3 doses of Benzathine penicillin 2.4 mU weekly • Erythromycin 500 mg 4 x daily for 15 – 30 days for true penicillin allergy • For a neonate • 25,000 IU/Kg Penicillin twice daily for 10 days • Follow up and treat the sexual partner

6. Rubella in Pregnancy Max Brinsmead PhD FRANZCOG October 2008

7. Rubella Infection • Caused by the pleomorphic RNA virus of the genus Rubivirus • Infects only human subjects • In adults and children causes: • Mild fever & malaise • Generalised fine erythematous rash – rarely purpuric • Cervical lymphadenopathy • Arthralgia

8. Rubella in a Pregnant Woman • Before 12 weeks pregnancy • Miscarriage • Cardiac anomalies • Nerve deafness • Cataracts or retinopathy • Mental retardation • Fetus somewhat safer in the 2nd trimester but… • In the second half of pregnancy • Hepatosplenomegaly • Failure to thrive, osteitis • Diabetes, hypothyroidism and GH deficiency • Progressive panencephalitis = The Congenital Rubella Syndrome

9. Prevention of Congenital Rubella • Immunise all children at 12 -15m (MMR) • Test all women who are pregnant (or plan to conceive) for immunity • Avoid infection if pregnant • Spread by nasopharyngeal droplets +/- 7 days from the time of rash • Retest any pregnant woman who is exposed to the virus • Terminate pregnancy for proven infection • Immunise women postpartum if low titre or non immune • Immunisation of a pregnant woman with the live virus is not recommended but is also not associated with teratogenesis

10. Herpes in Pregnancy Max Brinsmead PhD FRANZCOG March 2010

11. Genital Herpes • 66% caused by H. simplex Type 2 • 33% associated with H simplex Type 1 • Is a latent and recurrent infection in up to 1:5 adults • ~1:50 women have this virus during pregnancy • But most are secondary (or recurrent) infections • Even if the woman says she has never had it before

12. Maternal Herpes • Primary infection can be disseminated with encephalitis, hepatitis and skin eruptions • Is more common in pregnancy because of the mild immunosupression which occurs • Concomitant HIV infection a real problem • Most infections during pregnancy are secondary • But recurrences are more common because of pregnancy-related immunosupression

13. Vertical Transmission of Herpes • Mostly occurs when the fetus contacts infected genital secretions • But intrauterine infection and FDIU possible • Neonatal infection is also possible • Disseminated Herpes occurs after primary maternal infection • Often with premature delivery

14. Risk of Vertical Transmission • With maternal primary Herpes the risk of neonatal infection is 26 – 56% • With maternal secondary Herpes the risk of neonatal infection is 1 – 3%

15. Diagnosis of Genital Herpes • Often unrecognised in its recurrent form • Typically localised pruritis and pain • Blister and ulceration • PCR is a sensitive and specific test if appropriate material is collected • Serum IgG and IgM can be useful in distinguishing primary and secondary infection • Viral culture

16. Herpes visible at the onset of labour • If thought to be a secondary infection then CS is not mandatory • Requires patient counselling and her choice should be respected • If there are ruptured membranes then delivery should be expedited • Fetal trauma should be avoided • The neonatal service should be alerted

17. Chickenpox in Pregnancy Max Brinsmead PhD MRCOG December 2007

18. Varicella • Caused by Herpes zoster • Different epidemiology in temperate and tropical climates • Causes • Chickenpox • Shingles • Fetal varicella syndrome (FVS) • In pregnancy maternal risks of pneumonitis (10%) are greater than the fetal risks of FVS (2%)

19. Fetal Varicella Syndrome • Greatest risk is maternal infection 13 – 20w • Mental retardation 50% • Skin scarring • Eye defects (micropthalmia, chorioretinitis and cataracts) • Limb hypoplasia • Bowel/Bladder dysfunction

20. Neonatal Varicella • Risk is greatest if maternal rash occurs 5 days before delivery and up to 2 days after • Transmission rate 20 – 60% • 30% neonatal mortality if untreated • Responds to the antiviral Acyclovir

21. Maternal Varicella in Pregnancy • Pneumonitis 10% • Hepatitis • Encephalitis • Acyclovir recommended

22. My Recommendations* • Prenatal screening and/or Immunisation • ZIG for non immune women who come into close contact with Varicella • Prophylactic oral Acyclovir for exposure >20w • Delay delivery >5 days after rash • Neonatal ZIG and Acyclovir for high risk neonate • Immunise health care workers • Exclude those non immune to Varicella from care of pregnant women for 8 – 21days after possible infection

23. Cytomegalovirus Infection and Pregnancy Max Brinsmead PhD FRANZCOG December 2010

24. Cytomegalovirus • Proper name is Human Herpesvirus 5 • 1:100 babies are born with this congenital infection • 1:10 of those infected will show some effect • 1:10 of those will have severe mental retardation • CMV is a common cause of mental retardation • And causes 30% of congenital neural deafness • ~40% of women are non immune when pregnant • Health workers and women with children who bring home CMV are most at risk • Vaccination is not possible • But trials are currently in progress

25. Neonatal CMV Syndrome • Small for dates • Failure to thrive • Hepatospenomegaly • Microcephaly • Cerebral calcifications • Chorioretinitis • Hearing deficits (may occur later in life) • The virus can be detected in urine and saliva

26. Toxoplasmosis and Pregnancy Max Brinsmead PhD FRANZCOG October 2008

27. Toxoplasmosis • Caused by the protozoan parasite Toxoplasma gondi • Is endemic in most societies • And the definitive host is cats • Has a complex life cycle but infectious oocysts can live for many months in soil • 10 – 25% of adults have serologic evidence of previous infection • In most it causes a mild illness with fever, malaise and lymphadenopathy • But transplacental infection can cause congenital disease

28. Congenital Toxoplasmosis • Mental retardation • Learning difficulties • Cerebral calcifications • Chorioretinitis blindness • Hydrocephalus • Epilepsy

29. Vertical Transmission • 50% of congenital Toxoplasmosis is due to eating contaminated meat, mostly pork • Remainder to to contact with cats’ faeces or contaminated soil • ~1:200 women will become infected during pregnancy • Of these ~1:10 will deliver a baby with congenital Toxoplamosis • Infection in early pregnancy is less likely to cross the placenta • But this has more serious effects when it does

30. Preventing Congenital Toxoplasmosis Pregnant women should: • Cook meat thoroughly and check core temperature with a cooking thermometer • Prevent contamination of food by uncooked meat • Avoid contact with cat faeces • Wash or peel vegetables and avoid contact with soil

31. Parvovirus Infection and Pregnancy Max Brinsmead PhD FRANZCOG December 2010

32. Parvovirus • Caused by Parvovirus B19 • Causes epidemic Fifth Disease or “Slapped Cheek Syndrome” in pre school children. • When intrauterine infection occurs it affects haemopoeisis. This results in fetal anaemia and hydrops fetalis. • However, recovery is usually spontaneous and complete and there are no long term sequelae

33. Vertical Parvovirus Transmission • 50-66% of pregnant women are Parvovirus immune • Most infections occur from the mother’s own pre school child • Spread by droplets c sneezing, coughing • Incubation period is 4 -14 days • Rash occurs on the face but also on hands, wrists & knees • Maternal symptoms include polyarthalgia, fever and non specific rash • Risk of maternal infection is increased by immune supression and during epidemics

34. Fetal Risk • Transplacental transmission rate is ~30% • Can cause hepatitis and myocarditis • 20% risk of fetal death in the 1st trimester • Causes up to 3% of miscarriages • Risk of hydrops is greatest in the second trimester • When a fetal death rate of about 15% • But by 20w the risk of fetal death has fallen to 6%