obs 2 Flashcards
what is polyhydramnios?
when there is increased amniotic fluid
what are the causes of polyhydramnios?
increase in fetal urine production (maternal diabetes, TTTS, fetal hydrops)
Fetal inability to swallow or absorb amniotic fluid (GI obstruction e.g. duodenal atresia, trachea-oesophageal fistula, fetal neurological or muscular abnormalities, idiopathic)
what are the complications of polyhydramnios?
preterm delivery
complications of the cause - e.g. duodenal atresia is associated with trisomy 21
malpresentation at delivery because of increase room for fetus
maternal discomfort because of abdominal distension
what investigations would you perform for polyhydramnios?
exclude maternal diabetes with a GTT
USS for examination of fetus
how should you manage polyhydramnios?
if severe (AFI>40) -> amnioreduction or NSAIDs
if there is a fetal abnormality refer to a fetal medicine centre
TTTS - laser ablation of placental anastomoses
if preterm assess risk of delivery with cervical scan and or fibronectin assay and consider steroids
if unstable or transverse lie at term admit to hospital
what is oligohydramnios?
when amniotic fluid volume is reduced
what are the causes of oligohydramnios?
PPROM IUGR leakage of amniotic fluid - SROM fetal renal failure or abnormalities post-dates pregnancy obstruction to fetal renal output
what are the complications of oligohydramnios?
lung hypoplasia if occurs <22 weeks
limb abnormalities e.g. clubbed foot
oligohydramnios before 22 weeks has a very poor prognosis
how do you manage oligohydramnios?
If SROM at 34-36 weeks - induce labour unless CS indicated for another reason
If SROM before 34-36 weeks: give prophylactic erythromycin, monitor for signs of infection, daily CTG, consider induction by 34-36 weeks
If IUGR: manage according to umbilical artery doppler and CTG
what are the principal functions of the placenta?
to anchor the fetus and establish fetoplacental unit
to act as an organ gaseous exchange
endocrine organ to bring the needed changes in pregnancy
transfer substances to the fetus
barrier against infection
what is breech presentation
the lie is longitudinal and the head is found in the fundus
the caudal end of the fetus occupies the lower segment
what are the three types of breech?
extended breech (frank breech 70%) - both legs extended with fee by head, presenting part is the buttock
Flexed breeches (15%) - legs flexed at knees so that both buttocks and feet are presenting
footling breeches (15%) - on leg flexed one leg extended
what are the risk factors/causes for breech presentation ?
most often idiopathic
is often associated with pre term delivery
previous breech presentation
uterine abnormalities
placenta praevia and obstruction to the pelvis
fetal abnormalities
multiple pregnancies
what are the consequences of breech presentation?
fetal complications - there is an increased risk of hypoxia and trauma in labour, there is an association with congenital abnormalities
cord prolapse is more common in breech presentations
what is the diagnosis of breech presentation ?
if diagnosed before 36 weeks It is not important unless in labour
breech presentation is commonly diagnosed before labour
on examination the lie is longitudinal and the head can be palpate at the fundus
the presenting part is not hard
the fetal heart is heard best high up on the uterus
USS can confirm the diagnosis
what can be used to change the presentation from breech to cephalic?
external cephalic version - manually turning a breech or transverse presentation into a cephalic one
after external cephalic version?
after the attempt, CTG is performed and anti-D given if the mother is rhesus -ve
what are some contraindications to external cephalic version?
- if a C-section is already indicated
- APH
- fetal compromise
- oligohydramnios
- rhesus isoimmunization
- pre-eclampsia
relative contraindications - one previous c section, fetal abnormality, maternal hypertension
other than breech presentation what are the other types?
transverse or oblique occurs when the axis of the uterus - common before term but uncommon after 37 weeks
unstable lie occurs when the lie is still changing, usually several times a day and may be transverse or longitudinal lie, and cephalic or breech presentation
how do you manage an abnormal lie?
admission to hospital at 37 weeks is usually recommended with unstable lie that that a c section can be carried out if labour starts or membranes rupture
why is there increased risk of anaemia in pregnancy?
because normal pregnancy has 2-3 fold increase in iron requirements and 10-20 fold increase in folate requirements in pregnancy
plasma volume expansion (50%) greater than red cell mass - this leads to physiological dilution with decreased Hb and haematocrit
what is the most common cause of anaemia in pregnancy?
iron deficiency anaemia
how should iron deficiency anaemia be treated?
oral iron supplementation - if not tolerated parenteral iron
*in situations such as multiple pregnancy with high risk then prophylactic iron should be given
what are risk factors for folate deficiency anaemia in pregnancy?
poor nutritional status
haematological problems with rapid turnover of blood cells e.g. haemolytic anaemia and haemoglobinopathies
drug interaction with folate metabolism e.g. antiepileptics
why is folic acid given pre-conception?
also given in early pregnancy
given to reduce risk of neural tube defect
who should be given high dose folic acid?
high dose = 5mg those on anticonvulsants a previous child with neural tube defects with demonstrated deficiency with diabetes with a BMI >35 with sickle cell disease
what ae the risks of sickle cell disease in pregnancy?
crisis are more common during pregnancy
increased risk of pre-eclampsia
increase risk of delivery by c section secondary to fetal distres
what are the fetal risk of sickle cell disease during pregnancy~?
miscarriage
IUGR
prematurity
still birth
