Perinatal medicine Flashcards
pregnancies are at increased risk of fetal abnormality include those in which:
- the mother is older
- previous congenital abnormality
- family history of an inherited disorder
- the parents are identified as carriers of an autosomal recessive disorder
- a parent carries a chromosomal rearrangement
- parents are close blood relatives (cosanguinity)
the fetus can sometimes be treated by giving medication to the mother, give examples:
- Glucocorticoid therapy before preterm delivery accelerates lung maturity and surfactant production.
- Digoxin or flecainide can be given to the mother to treat fetal supraventricular tachycardia.
What can be detected on antenatal blood sampling from mother?
- Hep B, syphilis, rubella, HIV,
- Neural tube defects (spina bifida or anencephaly),
- Trisomies (combined with USG and confirmed with amniocentesisi or chorionic villous sampling).
What can be detected on ultrasound screening?
- Gestational age
- Multiple pregnancies
- Structural malformation
- Fetal growth
- Amniotic fluid volume (oligohydramnios/polyhydramnios, potter syndrome)
What can we detect with amniocentesis?
chromosme/microarray and DNA analysis
What can we detect with fetal blood sampling?
fetal Hb for anemia, fetal infection serology and fetal blood transfusion
What can we detect with chorionic villus sampling?
chromosome/microarray and DNA analysis, fetal infection (PCR) and enzyme analysis of inborn error of metabolism.
What can we detect with Preimplantation genetic diagnosis (PGD)?
in vitro fertilization allows genetic analysis of cells from developing embryo before transfer to the uterus
What can we detect with fetoscopy?
minimal invasive surgery (laser photocoagulation of communicating vessels in twin-twin transfusion syndrome)
What can we detect with non-invasive prenatal testing (NIPT)– cell-free fetal DNA (cffDNA) from maternal blood?
identification of Down syndrome and other chromosomal disorders, fetal gender and rhesus status.
there are few conditions in which therapy can be given to fetus directly, which?
- Rheus isoimmunization–> severely affected fetuses become anemic and may develop hydrops fetalis, with edema and ascites.
- Perinatal isoimmune thrombocytopenia–> this condition is analogous to thesus isoimmunization but involves maternal antiplatelet antibodies crossing the placenta.
How can we detect placental insufficiency and IUGR?
monitor closesly: biophysical profile (amniotic fluid volume, fetal movement, fetal tone, fetal breathing movements and fetal heart activity) and doppler blood flow velocity (umbilical and middle cerebral arteries)
The management of preterm labour may involve:
- antenatal corticosteroids
- antibiotics reduce risk of amnionitis and neonatal infection.
- tocolysis- suppress uterine contractions to try and suppress labour and allow completion of the course of antenatal steroids.
- magnesium sulphate-reduces the incidence of cerebral palsy
The main problems for the infant associated with multiple births are:
- Preterm labour
- IUGR
- Congenital abnormalities
- Twin-twin transfusion syndrome in monochroionic twins
- Complicated deliveries
Poorly controlled maternal diabetes is associated with:
polyhydramnios and preeclampsia, increased rate of early fetal loss, congenital malformations and late unexplained intrauterine death.
Fetal problems associated with maternal diabetes are:
- Congenital malformations (cardiac malformations, sacral agenesis, and hypoplastic left colon)
- IUGR
- Macrosomia
Neonatal problems associated with maternal diabetes are:
- Hypoglycemia
- Respiratory distress syndrome
- Hypertrophic cardiomyopathy
- Polycythemia (venous hematocrit>0.65): makes the infant look plethoric
Can thyroid stimulating immunoglobulin (Hyperthyroidism) cross the placenta?
yes, and it can cause hyperthyroidism in the fetus
How can we detect hyperthyroidism in the fetus?
fetal tachycardia of CTG (cardiotocography) trace, and fetal goitre may be evident on ultrasound.
How can we detect hyperthyroidism in a neonate?
irritability, weight loss, tachycardia, heart failure, diarrhea and exophthalmos in the first 2 weeks of life
How to treat hyperthyroidism in neonates?
anti-thyroid drugs until the condition resolves.
SLE in mother is associated with what outcome?
- recurrent miscarriage
- IUGR
- pre-eclampsia
- placental abruption
Can the SLE antibodies cross placenta and if so, which?
Ro (SS-A) or LA (SS-B)
There is also a sel-limiting rash
Can autoimmune thrombocytopenic purpura in a pregnant women affect the fetus?
Yes, IgG can cross the placenta and damage fetal platelets.
What can severe fetal thrombocytopenia cause in fetus?
intracranial hemorrhage following birth trauma
What should be given to infants with severe thrombocytopenia or petechia?
IV immunoglobulin
Maternal medication that may adversely affect the fetus is:
- Anticonvulsant drugs
- Cytotoxic drugs
- Iodides/propylthiouracil
- Lithium
- SSRIs
- Tetracycline
- Thalidomide
- Vit A and retinoids
- Warfarin
What is the clinical syndromes of fetal alcohol syndrome?
- growth restriction
- developmental delay and cardiac defects (70%)
- face: saddle-shaped nose, maxillary hypoplasia, absent philtrum between the nose and upper lip, and short, thin upper lip, also a strawberry nevus
maternal cigarette smoking is associated with increased risk of?
- Misscariage and stillbirth
- Reduced birthweight and IUGR
Drugs given during labor and their adverse effects:
- Opioid agents: may suppress respiration at birth
- Epidural: may cause maternal pyrexia during labour
- Sedatives (diazepam): may cause sedation, hypothermia and hypotension
- Oxytocin and prostaglandin F2: may cause hyperstimulation of the uterus leading to fetal hypoxia
- IV fluids: may cause neonatal hyponatremia
