Multiple Gestation, Eclampsia, Antenatal Growth Charts & Infections in Preg Flashcards
Multiple gestation (pregnancy of >1 foetus): What are reasons for multiple births?
- If >1 egg is released during 1 menstrual cycle
- If the zygote divides after fertilisation=identical twins
- IVF treatments-often transfer >1 embryo to the uterus
What is amnionicity?
Number of amnions (inner membranes) that surround babies in multiple pregnancy
Pregnancies with 1 amnion (so that all babies share an amniotic sac) are monoamniotic, pregnancies with 2 amnions=diamniotic
What is chorionicity?
Number of chorionic (outer) membranes that surround babies in multiple preg
1 membrane=monochorionic
2 =dichorionic
What are the 4 types of twin preg?
- Dichorionic diamniotic twins (DCDCA) -can happen from 2 separate eggs fertilised by 2 separate sperms or can happen from an early division of the zygote
- Each baby has a separate placenta and amniotic sac - Monochorionic diamniotic twins (MCDA)-both babies share a placenta but have separate amniotic sacs
- MCMA-both babies share a placenta and an amniotic sac
- Conjoined twins
How is zygosity and chorionicity determined?
Fetal USS
What does the lambda sign compared to the T sign show on a fetal USS?
- Lambda sign=2 placentas-diagnoses dichorionic diamniotic twins
- T sign=single placenta-diagnoses monochorionic diamniotic twins
What are maternal complications of multiple gestation?
o Preterm labour
o Hyperemesis
o Anaemia in pregnancy
o HT
o Gestational diabetes
o PPH
What are foetal complications of multiple gestation?
o Growth restriction
o Prematurity
o Increased birth complications
o Increased perinatal mortality/morbidity
What are some complications that are associated especially with monochorionic twins?
o Twin-twin transfusion syndrome (when blood moves from one baby to another due to having a shared placenta- that baby then loses blood & is called the donor twin)
o Selective growth restriction
o Twin anaemia polycythaemia sequence
o Twin reversed arterial perfusion (TRAP)
o Single twin death
What antenatal care is required for multiple gestation?
- Routine care including trisomy 21 screening/structural scans
- Specialist clinic with regular scans to monitor growth & identify complications
- Dichorionic diamniotic require at least 8 AN visits
- Monochorionic require at least 11 AN visits
- Monitor BP/commence oral iron if required
- Monitor for iron deficiency anaemia
About 1/3 of twins are delivered via what?
CS
When should an earlier delivery be aimed for?
If there are any maternal/foetal complications
At what week and by what mode of delivery should DCDA, MCDA and triplets?
DCDA - 37 weeks
MCDA-36 weeks
- Vaginal delivery/CS (if 1st twin isn’t cephalic offer CS)
Triplets-35 weeks - CS
What is eclampsia compared to preeclampsia?
Eclampsia=When severe pre-eclampsia is complicated with generalised convulsions
Preeclampsia = a hypertensive disorder of pregnancy with multi organ involvement characterised by new onset HT, proteinuria usually seen after 20 weeks gestation
What does eclampsia happen as a result of?
Happens as a result of cerebral oedema &/or cerebral haemorrhage
What are the clinical features/warning signs of potential eclampsia?
o Headache
o BP > 160 systolic
o Hyperreflexia
o Visual changes
What type of seizures are associated with eclampsia?
Tonic clonic seizures
Is eclampsia an emergency?
Obstetric emergency managed with an ABC approach (secure airway, IV access & take bloods (LFT, U&E, coagulation & FBC)
How is eclampsia managed (think medications)?
Magnesium Sulphate (Given IV & protocol means it is usually kept in every room in clinical areas in a maternity hospital in case of emergency)
Causes cerebral dilatation-competitively blocks CA at synaptic nerve endings
Helps in the treatment & prevention of eclampsia & should be continued for 24hrs post delivery
Resp rate, Reflexes & Urine output should be monitored whilst on it
o Antihypertensives – labetolol, hydralazine
What is the antidote for magnesium sulphate?
Antidote=Calcium Gluconate & should be given If toxicity develops
What is the only cure for eclampsia?
Delivery of child
What are other complications of eclampsia to watch out for?
HELLP syndrome
DIC
Acute respiratory distress
Pulmonary oedema
Aspiration
Fetal hypoxia
Increased maternal mortality
How can the risk of pre-eclampsia in subsequent pregnancies be decreased?
Low dose aspirin given from 12 weeks gestation
Why are antenatal growth charts important?
Important method for detecting foetuses that are large or small for dates – failure to detect this can lead to increased morbidity or mortality
What are causes of a small baby (estimated foetal weight<10th centile)?
- Uteroplacental insufficiency
- Chromosomal abnormalities
- Foetal abnormalities
- Foetal infections
What are causes for a big bay (estimated foetal weight >90th centile)?
- Maternal DM
- Gestational diabetes
- Insulin dependent diabetes
Use of what charts have been shown to have better foetal outcomes and a lowers still birth rate?
Customised growth chart-customised for the mother’s weight, parity & ethnicity
What can be included on an antenatal growth chart?
- Dark lines to indicate 90th and 10th centile
- X to mark symphysis fundal height
- Each dot is estimated foetal weight
- Any change in the curve warrants further review by the obstetric team
- Gestation
In the UK what percentage of people are immune to chicken pox?
90%
How is chicken pox spread and what are the symptoms of it?
- Spread by respiratory droplets
- Fever, Malaise, Itchy vesicular rash
How long is the period of infectivity for chicken pox?
Period of infectivity=48 hrs before rash develops to once lesions have ‘crusted’ over (usually takes 5-7 days)
Who does chicken pox effect?
- Usually harmless & self-limiting in children but is associated with higher morbidity in adults (Risk of developing Hepatitis, pneumonitis & encephalitis- especially pronounced risk in the immunocompromised & pregnant)
- Small risk of congenital infection if maternal infection in first 28 weeks of pregnancy
What are the symptoms/signs of fetal varicella syndrome?
- Skin scarring
- Neurological abnormalities
- Congenital eye abnormalities
- Hypoplasia of ipsilateral limbs
No increased risk of miscarriage
Maternal infection with varicella in the last 4 weeks of preg significant increase the risk of what?
Infection in newborn
If there is significant exposure to varicella infection in pregnant women who is unsure if she is immune what should be checked?
Immunity status by taking serum IgG
- If immune (IgG +ve)=reassure
- If non immune=offer VZ immunoglobulin ASAP
Even after receiving immunoglobulin- still small chance of developing chicken pox. Also has no therapeutic benefit once chicken pox has developed
What should be prescribed for a mild infection of varicella?
> 20 weeks gestation offer oral aciclovir (also consider if < 20 weeks gestation)
Also advise symptomatic treatment and hygiene to prevent secondary bacterial infection
What should be done for a severe infection of VZ?
Give IV aciclovir and admit to hosp
What is shingles/herpes zoster caused by?
Reactivation of chicken pox virus that has remained dormant in the sensory nerve root ganglion since primary infection (although rare it is still possible to catch chicken pox from someone with shingles)
Who gets parvovirus B19?
~50% of pregnant woman will be immune
o Common & mild febrile illness of childhood
o Adults may be susceptible if they have never been exposed
How is parvovirus B19 spread is there a vax or treatments available and what are the symptoms of it?
o Fever, rash & erythema of the cheeks
o Most adults are asymptomatic
o No vax or treatment available
What can happen to the immunocompromised and pregnant people if they have parvovirus B19?
o In the immunocompromised can cause aplastic anaemia & haemolysis
o Infection during pregnancy can lead to foetal anaemia resulting in cardiac failure, Hydrops fetalis (swollen liver, severe abdominal swelling) & fetal death
o Rarely it can cause a pre-eclamptic condition in the mother with significant oedema
o Fetal infection 5 wks after maternal infection
When is the critical exposure period for parvovirus B19?
Critical exposure period=12-20 wks
Blood sample Immunoglobulin testing done in the pregnant woman exposed or who have possible illness – weekly scans done if test comes back +ve to monitor for foetal complications
What protozoa organism causes toxoplasmosis?
Toxoplasma gondii
How is toxoplasmosis transmitted and what are the symptoms of it?
-Transmitted through cat faeces & undercooked meats
-~20% are immune
-Asymptomatic OR mild flu like symptoms e.g, fever, sore throat, coryza, arthralgia
Parasitaemia occurs within 3 weeks of ingestion
Placental infection is possible both during pregnancy & immediately prior to pregnancy
Pregnant women should be advised to avoid cleaning cat litter trays and eating undercooked meat
What are some potential serious complications of toxoplasmosis?
Serious complications
o Chorioretinitis
o Encephalitis
o Myocarditis
o Pneumonitis
Although congenital infection with toxoplasmosis is rare there can be foetal complications in what trimester is the foetus at the highest risk?
Infection in the 3rd trimester
- PCR analysis of amniotic fluid (amniocentesis) can identify it & may confirm congenital infection
What infections are screened for at booking appointments (preg)?
HIV, Hep B & Syphilis are screened for at booking appointment (Hep C is not)
Does HIV increase the risk of congenital abnormalities?
NO
But there is an increased risk of pre-eclampsia, miscarriage, preterm delivery and low birth rate
- Serial 4 weekly foetal growth scans can be offered
What happens with all babies born to HIV +ve mothers?
All babies born to HIV +ve mothers should be referred to neonatology & offered HIV testing
What are the aims of combined anti-retroviral treatment (cART)?
- Viral load <50 HIV RNA copies/ml (allows vaginal delivery)
- Reduce risk of vertical transmission
- Improve mother’s health
All women are recommended to continue antiretroviral treatment postnatally
Breastfeeding also increases the risk of vertical transmission of HIV
What needs frequent monitoring when on antivirals?
LFTs & CD4 count & HIV viral load
What is the difference between the risks of acute and chronic Hep B?
- Acute infection in pregnancy – majority of babies contract Hep B at birth and is at risk of later cirrhosis & hepatocellular cancer
- Chronic HBV with a high viral load should be offered Tenofovir monotherapy in the 3rd trimester to reduce risk of transmission to baby
Is the Hep B vax safe in preg?
Hep B vax is inactivated so can be safely given to pregnant women who are at high risk such as IVDU, partner who is IVDU/has HBV or HIV
How are babies treated in terms of Hep B immunoglobulin and vax if mothers have Hep B?
- Hep B immunoglobulin should be offered to babies whose mothers have Hep B & an accelerated immunisation schedule is advised
- Testing at 1yr of age will identify any babies for whom this intervention has not been successful & who have become chronically infected with Hep B
- Response to Hep B vax may be reduced in preterm or low birth weight babies although vax schedule is same as term babies
What can Hep C lead to and what is it usually associated with?
- RNA virus that can lead to severe hepatitis, chronic liver disease & an increased risk of liver cancer
- 1-2% of pregnant women
- Most cases are associated with prior injecting drug use
- Pregnancy is associated with a decline in liver function in those with Hep C
- Vertical transmission occurs In 1 in 20 births (higher if woman is co-infected with HIV)
With Hep C can it be treated in pregnancy?
- No preventative means to stop transmission from mother to baby
- No treatment in pregnancy (as drugs used are teratogenic)
- Vaginal birth & breast feeding is safe (no further evidence of additional increased transmission risk)
What spirochete causes syphylis?
TREPONEMA PALLIDUM
How is syphylis:
1. Spread
2. Cured
3. What happens if left untreated?
- Spread by direct contact with a skin lesion that most commonly occurs during sexual contact
- Cured by course of Abx (IM Penicillin)
- Left untreated- chronic syphilis can cause neurological, cardiac, skeletal & skin abnormalities for adults & babies affected in utero
Why can get syphylis more than once and what issues can it cause to do with preg?
- Infection more than once is possible (as protective Abs are not produced in past infection)
- Pregnancy does not appear to alter the disease course – prompt treatment should be offered
- Increased risk of miscarriage, stillbirth, hydrops fetalis, growth restriction & congenital infection
What is the disease course of syphylis?
- Can be transmitted to baby trans-placentally or via exposure to an infected lesion at the time of birth
- Primary syphilis= painless, local ulcer known as a chancre
- If untreated 4-10 wks later symptoms of 2ndary syphilis present & if still left untreated can progress to tertiary (usually takes 20-40 years)
- Congenital infection can present in first 2 years of life or later
- Most are asymptomatic at birth but will develop symptoms within 5 wks
- Presentations vary but severe multisystem disease can occur
How does late congenital syphylis present?
- Late congenital syphilis=at or>2yrs of age who acquired the infection trans-placentally
o Hutchinson’s triad (frequently found group of symptoms seen in 63% of all cases)
o Treatment with penicillin before the development of late symptoms is essential
What is Hutchinson’s triad seen in late congenital syphylis?
- Deafness
- Interstitial keratitis
- Hutchinson’s teeth-widely spaced, peg like
