Obstetrics Flashcards
fecundity
the capacity to conceive (measured as the monthly probability of conception - normal is 20% for fertile women)
asthenozoospermia
abnormal sperm motility
teratospermia
abnormal sperm morphology
Naegele’s rule
Due date = LMP + 280 days (9mnths + 7ds)
Severe nausea & vomiting during pregnancy (–> LOW & dehydration)
Hyperemesis gravidarum
Zygosity
number of fertilised eggs
chorionicity
number of placentae
amnionicity
number of amniotic cavities
One fertilised egg, separates <3 days
dichorionic diamniotic pregnancy (DCDA)
One fertilised egg, separates in days 4-8
monochorionic diamniotic pregnancy (MCDA)
One fertilised egg, separates in days 7-12
monochorionic monoamniotic pregnancy (MCMA)
One fertilised egg, separates >12 days
conjoined twins
Monochorionic twins, 1 twin hyperperfused 1 twin hypoperfused, 1 twin polyhydramnios 1 twin oligohydramnios
Twin-to-twin transfusion syndrome (TTTS)
Miscarriage
Spontaneous loss of intrauterine pregnancy <20wks gestation
Recurrent miscarriage
3+ consecutive pregnancies lost
pelvic pain (unilateral –> generalised), shoulder tip pain, delayed period, abnormal bleeding, tender adnexal mass, shock, peritonism
Ectopic pregnancy
Implantation of the fertilised ovum in tissue other than the
endometrium of the uterine cavity
ectopic pregnancy
Most common site of ectopic pregnancy
fallopian tube (97%)
Infant - cicatricial skin lesions, limb hypoplasia, microcephaly, ophthalmic lesions
congenital varicella syndrome (CVS)
Flu-like illness + unpasteurised milk, soft cheeses, pre-prepared salads, uncooked seafood, processed meats
Listeria monocytogenes
Infection of the amniotic fluid, placenta, membranes and/or decidua
Chorioamnionitis
Pre-eclampsia
de novo hypertension arising >20 weeks gestation, returning to normal within 3 months postpartum, plus evidence of dysfunction in at least one other organ (placental disorder)
Eclampsia
pre-eclampsia + convulsions
Gestational HTN
de novo hypertension arising >20 weeks gestation without any other feature of preeclampsia, returning to normal within 3 months postpartum
In pregnancy - headaches, visual scintillations, epigastric/RUQ pain, oliguria, lower abdominal pain, bleeding (placental abruption), reduced foetal movements
Pre-eclampsia (+ convulsions = eclampsia)
Carbohydrate intolerance of variable severity with onset or first recognition during pregnancy
Gestational DM
Pruritus in the absence of a skin rash with abnormal LFTs (in pregnancy)
Cholestasis of pregnancy
The three Ps of delivery
Passenger (foetus), Passage (pelvis), Power (uterine contractions)
Foetal lie
relationship of the long axis of the foetus to the long axis of the mother. 1. longitudinal (cephalic = head first, breech = bottom/foot first) 2. transverse 3. oblique
Macrosomia
Large for gestational age = estimated foetal weight >90th percentile (birth weight >4500g)
Small for gestational age (SGA)
Estimated foetal weight (EFW) or abdominal circumference <10th percentile
Severe SGA
EFW or abdominal circumference <3rd percentile
SGA + problems (erratic growth, haemodynamic compromise, risk of poor outcomes)
Foetal growth restriction (FGR)
Foetal position
the relationship of the denominator (occiput) to the maternal pelvis
Foetal presentation
the part of the foetus that will present first (cephalic/vertex, shoulder, breech (foot/bottom))
Frank breech
hips flexed, knees extended
Complete breech
hips flexed, knees flexed, feet not below level of foetal buttocks
Footling breech
one or both feet presenting below level of the foetal buttocks
Stages of labour
1st (regular painful contractions –> full cervical dilation), 2nd (full cervical dilation –> delivery of infant), 3rd (delivery of infant –> delivery of placenta & membranes)
Episiotomy
An incision through the perineum made to enlarge the
diameter of the vulval outlet and assist childbirth
Perineal trauma
First-degree tear = injury to vaginal or perineal skin only
Second-degree tear = + injury to perineal muscles.
Third-degree tear = + involvement of anal sphincter muscles.
– 3a = <50% of external anal sphincter torn.
– 3b = >50% of external anal sphincter torn.
– 3c = internal anal sphincter also torn.
Fourth-degree tear = + injury to the rectal mucosa
Stillbirth
birthweight of >400g or a gestation of >20 weeks
Neonatal death
death <28 days after birth
Infant death
death >28 days after birth
Postpartum haemorrhage (primary)
> 500ml of blood loss within 24 hours after vaginal delivery
Placental abruption
bleeding causes premature separation of the placenta from the wall of the uterus
Shoulder dystocia
the foetal shoulders become impact in the maternal pelvis after delivery of the foetal head
Cord prolapse
descent of the umbilical cord alongside or beyond the presenting part in the presence of ruptured membranes
Antepartum haemorrhage
Bleeding from the genital tract after 20 weeks gestation
In pregnancy - PV bleeding, continuous abdominal pain, tenderness on palpation, “woody’ uterus
Placental abruption
Placenta praevia
Implantation of the placenta in the lower segment of the uterus
Placenta accreta
placenta is morbidly adherent to the uterine wall
Placenta increta
placenta invades into the myometrium
Placenta percreta
placenta invades through the myometrium and the serosa of the uterus and may invade other body organs
Vasa praevia
Foetal blood vessels run in the amniotic membranes below the presenting part of the foetus in front of the cervix, with no placenta or umbilical cord present
In pregnancy - vaginal bleeding, acute foetal bradycardia, foetal vessels palpable over the membranes
vasa praevia
“Turtle necking” of foetal head during delivery
shoulder dystocia
Acute maternal collapse + foetal squames in maternal lungs
Amniotic fluid embolism
Secondary postpartum haemorrhage
excessive vaginal bleeding from 24 hours to 6 weeks after birth
During labour - abdominal pain, vaginal bleeding, +/- haematuria, contractions cease, decelerations on CTG, previous Caesarean delivery
Uterine rupture
Uterine inversion
The uterine fundus descends either through the uterine cavity, through the cervix, or beyond the introitus. Caused by traction on the umbilical cord before the placenta has separated
Preterm birth
Delivery <37wks gestation
Preterm Pre-Labour Rupture of Membranes
Spontaneous rupture of membranes prior to 37 weeks gestation and before the onset of labour
Term Pre-Labour Rupture of Membranes
Spontaneous rupture of membranes at or after 37 weeks gestation and before the onset of labour
Trimesters
1st trimester: 0-12wks
2nd trimester: 13-27wks
3rd trimesters: 28wks-birth
What is bHCG produced by?
Syncytiotrophoblast cells of the outer layer of the chorionic villi
What is the function of bHCG?
To maintain the corpus luteum & stimulate its secretion of progesterone (structurally similar to LH)
Causes of recurrent second trimester miscarriages
Septate/bicornuate uterus (due to incomplete fusion of paramesonephric ducts), cervical incompetence, antiphospholipid syndrome/SLE
Causes of polyhydramnios
Maternal DM, foetal anencephaly, duodenal atresia (commonly assoc w Down’s foetus –> “double bubble” appearance on USS)
PAPP-A
pregnancy associated plasma protein A (decreased in Down’s foetus)
Sheehan syndrome
perinatal pituitary necrosis cause by hypovolemia (ie due to blood loss - PPH, placental abruption)
