Infections in Pregnancy

Dr Shahnaz Aram

General Principles

Pregnancy does not alter resistance to infection

Severe infections have greater effects on the fetus

Maternal antibodies cross the placenta and give passive immunity to the fetus

Fetus becomes immunologically competent from the 14th week

Fetus and Infection

• Indirect effect - O2 transport, nutrient exchange

• Direct effect - invasion of placenta and infection of fetus

• Viruses more than bacteria• rarely effect fetus unless maternal infection is severe

– exception: Rubella, CMV, Herpes Simplex

Fetus and Infection

Infections cause- miscarriage- congenital anomalies- fetal hydrops- fetal death- preterm delivery- preterm rupture of the membranes

Viral Diseases

• Rubella• Parvovirus• Cytomegalovirus• Varicella Zoster• Herpes• Hepatitis• HIV• Rubeola

Measles (Rubeola)

• Paramyxovirus• Incubation - 10-14 days• Respiratory droplet inoculation• Fever, rash, cough, rhinorrhea,

conjunctivitis and Koplik’s spots• Pneumonia (2nd bacterial) main cause of

death• Encephalomyolitis, SSPE, Hepatitis

Measles (Rubeola)

• No increased maternal or fetal deaths• Risk of preterm delivery• No specific syndrome• Neonatal measles and pneumonia if active

disease in mother• Increased PNM in developing countries

Measles (Rubeola)

• Prevention vaccine (95% recipients protected)

• Treatment antipyrexialscough suppresantsAntibiotics for bacteriaSuppress uterine contractions? Immune serum globulin

• Isolation precautions

Rubella

• Togavirus (RNA virus)• Incubation - 14-21 days• Respiratory droplet inoculation

– only modestly contagious

• Fever, rash (3 days), cough, arthralgias, post auricular and suboccipital lymphadenopathy

• Usually mild, overt clinical symptoms 50-75% of cases

• Encephalitis, bleeding diathesis & arthritis are rare complications

Rubella and the Fetus

• Purpura, Splenomegaly, jaundice, meningoencephalitis, thrombocytopenia are transient

• Congenital cataracts, Glaucoma, heart disease, deafness, microcephaly and mental retardation are permanent abnormalities

• Diabetes, thyroid abnormalities, precocious puberty & Progressive panencephalitis (late)

Rubella

• Vaccination (95% seroconversion)@ 15 months and early adulthood

• Immune status checking in teenagers, pre-college and pre-pregnancy

• Antenatal testing• Serology testing for presumed exposures

(paired Sera)• No in-utero therapy

Parvovirus

• Human parvovirus B19 (DNA virus)- erythema infectiosum in childhood- chronic arthropathy- chronic bone marrow failure (immunodefic)- aplastic crisis (Sickle disaease)

• Incubation 4-14 days• Respiratory droplet spread• High fever, “Slapped cheek syndrome’

non specific rash, no symptoms

Parvovirus and fetus

• Hydrops (anaemia, myocarditis)• Adults 60% sero-positive• 1/3 fetuses affected in acute infection• Fetal loss rare with appropriate treatment• Assess serology - IgG, IgM, paired serology

• Serial ultrasound, intrauterine transfusion

Varicella

• Varicella-Zoster virus (DNA)• Incubation - 10-20 days• Respiratory droplet inoculation• Fever, malaise, pruritic rash (maculopapular

with vesicles) • Pneumonia (+/- bacterial), encephalitis,

myocarditis, pericarditis and adrenal insufficiency especially in adults

Varicella and pregnancy

• Mild immunocompromise of pregnancy increases risk

• 10% develop pulmonary complications - main cause of mortality

• Fetal effectsPreterm deliveryVaricella syndromeNeonatal varicella (VZ first 2 months)

Varicella SyndromeCutaneous scarringLimb hypoplasiaMissing/hypoplastic digitsLimb paralysis/muscle atrophyPsychomotor retardationConvulsionsMicrocephalyCerebral atrophyChorioretinitis/ chorioretinal scarring/optic disc hypoplasiaCataractsHorner’s SyndromeEarly childhood Zoster

Cytomegalovirus

• DNA virus• Congenital infection - 1%• 5-10% of those infected show clinical

illness at birth• Neonatal MR - 20-30%• 90% of survivors get late complications• 5-15% with no demonstrable disease at

birth get some abnormality (deafness)

CMV Congenital Infection

• Hepatomegaly }• Spleenomegaly }• Jaundice }TORCH• Thrombocytopenia }Syndrome• Petechiae }• Microcephaly }• Intrauterine growth retardation }

CMV Congenital Infection (Late)• Venticulomegaly• Cerebral atrophy• Mental retardation• Psychomotor delay• Seizures• Learning difficulties and language delay• Chorioretinitis / Optic atrophy• Intracranial calcifications• Long bone radiolucencies, dental abnormalities• Pneumonitis

CMV Congenital Infection

• Prolonged virus shedding

• No vaccine

• No treatment

• Risk group advice

Herpes Simplex

• Disseminated disease in pregnant woman - death from hepatitis, encephalitis

• Miscarriage (severe disease)• No congenital syndrome known• Intrapartum infection

• disseminated disease - chorioretinitis, meningitis, encephalitis, mental retardation, seizures and death

• Primary infection >>>secondary infection• HSV II - 75%; HSV I - 25% cases

Hepatitis B

• Intrauterine infection - 5%• Intrapartum infection - 95%• Congenital infection - 90% chronic carriers • About 1% mothers are potential risks for

their newborns• Newborns should receive passive (HBIg)

and active immunization (vaccine x 3 doses) - protective in over 90% of cases

Hepatitis C

• Risk of transmission to fetus 6-30%• Increased if other infections such as HIV• No treatment• Value of C Section is uncertain• Avoid invasive procedures

HIV

• Infection rates variable• Risk of vertical transmission 20-40%,

mostly peri-partum• Screening and treatment can almost

completely reduce vertical transmission• C Section reduces risk of transmission x 4-

fold• Viral counts <1000 - negligible risk to fetus

Bacterial Infections

• Bacteruria*• Vaginal infections (BV, TV, Candida)• Group B Streptococci*• Gonorrhoea*• Chlamydia*• Toxoplasmosis*• Listeria

Bacteruria

• Asymptomatic• 5-8% of all pregnancies (2% Non-preg)• Urinary stasis, tract dilatation• 30% symptomatic UTI (Pyelonephritis)• Diagnosis• Treatment• Subsequent care (MSU v Prophylaxis)

Group B Streptococci

• 25% women are carriers• 50% of babies born will be colonized• 1-2% will have Grp B Strep infection• 1:1000 babies• Pneumonia (early), Meninigitis (Late)

• Screening v Risk factor prophylaxis

Gonorrhoea

• Neissseria Gonorrhoea (1-6% pop)• Pre-term labour, PPROM,

Chorioamniionitis, Endometritis• Gonococcal opthalmia neonatorum (40%)• 80% asymptomatic• Screening needed?• Cephtriaxone IM stat

Chlamydia

• 5-7% reproductive population• Pre-term labour, PPROM,

Chorioamniionitis, Endometritis• Conjunctivitis (18-50%), Pneumonia (18%)• Most are asymptomatic• Screening needed• Azithromycin 1 gram stat

Syphilis

• T.Pallidum• <1:1000 pregnant women• Can infect trans placenta from 15th week• Second stage by birth if not treated• Screening – VDRL, RPR• Diagnostic tests – TPI, FTA-Abs• High dose Penicillin's

Toxoplasmosis

• Toxoplasma Gondii (Protozoa)• Cat faeces, raw/undercooked meats• TORCH syndrome• Chorioretinitis, Encephalitis, Neonatal

Jaundice• Serology =/- PCR• Sulfonamides + Pyrimethamine

Intra-Amniotic Infection

• 1-2% all deliveries• Clinical Diagnosis – fever, uterine tenderness,

Leucocytosis• Histologic chorioamnionitis more common• Ascending infection, rarely haematogenous• Polymicrobial• Increased PTD, PNMR, C Palsy, Endometritis• Treatment – Antibiotics and delivery

Miscellaneous

• Malaria• Mycoplasma• HPV• Tropical diseases