Case 14- pregnancy complications Flashcards
Neonate
Infant younger then 28 days
IUGR
Intrauterine growth restriction, where growth slows or ceases in-utero. Different to SGA as it applies to neonates with malnutrition and is irrespective of birth weight percentile. IUGR is when growth slows or stops
Extreme pre-term
<26 weeks of pregnancy
Pre-term
<37 weeks of pregnancy
Term (baby)
37-42 weeks of pregnancy
Post term
> 42 weeks of pregnancy
Small for gestational age (SGA)
Birthweight <10th centile for gestational age
Large for gestational age (LGA)
Birthweight >90th centile for gestational age
Low birthweight
<2500g
Very low birthweight
<1500g
Extreme low birthweight
<1000g
Placental causes of IUGR
Placental insufficiencies, Pre-eclampsia, Placental Abruption.
Foetal causes of IUGR
Multiple pregnancies, Chromosomal abnormalities (trisomy 13, 18 or 21), Major congenital abnormalities (congenital heart disease, neural tube defect, abdominal wall defects) and Rare genetic syndromes.
Maternal causes of IUGR
Age, Low socio-economic status, Parity, Inter-pregnancy interval, Previous delivery of SGA / IUGR baby, Substance abuse, Medication, Pre-pregnancy BMI, Assisted reproductive technologies, Medical conditions, Infections (viral).
Pre-term risk factors= Previous preterm birth / late miscarriage
Most likely risk factor for preterm baby. Future pregnancies need specialist treatment
Complication= preterm baby, stillborn or neonatal death
Difference between preterm and miscarriage
Late miscarriage= 12-24 weeks
Preterm= from >24 to <37 weeks
Pre-term risk factors= Cervical surgery
Overview- weakness of cervix, fetus not suspended as well, the pressure can induce early labour. Can happen at any time. Due to procedure on cervix or infection.
Complication- preterm baby / neonatal death
Pre-term risk factors= Pre-eclampsia
BP >160 or >110 diastolic with proteinuria. Can cause eclamptic fit and death. Asymptomatic, cured by delivery of the placenta. Usually around 30-34 weeks.
Complications= Preterm baby, eclampsia, maternal and neonatal death, renal failure, IUGR and fetal compromise
Pre-term risk factors multiple pregnancies
All multiple pregnancies are high risk and need consultant led care.
Complications- miscarriage and preterm delivery, IUGR, congenital abnormalities, cerebral palsy and disability
Pre-term risk factors- IUGR
Failure to thrive in utero. Can occur throughout the pregnancy.
Complications= increased perinatal mortality rates, Cerebral palsy rates, emergency C section, Meconium aspiration, Stillbirth, Hypoglycaemia and Hypocalcaemia
Biological consequences of foetal growth restriction
Poor growth
Cerebral palsy, gross motor and minor neurological dysfunction.
↑ chance of developing diabetes, hypertension, obesity, metabolic syndrome, coronary heart disease before adulthood.
Psychological consequences of foetal growth restriction
Lower levels of intelligence.
Lower scores on cognitive testing.
Behavioural problems: hyperactive behaviour, attention deficit hyperactivity disorder.
Poor perceptual performance, poor visuo-motor perception.
Social consequences of foetal growth restriction
Poor academic performance
Difficulties in school or requiring special education
Low social competence
Rooting reflex
Stroking an infants cheek or corner of their mouth will cause the infant to turn their head and open their mouth.
Babkin reflex
A neonate whose palms are firmly stroked will open its mouth, close its eyes, and tilt its head forward
Plantar gasping reflex
Stroking the ball of the foot causes the infant to curl their toes and attempt to grab the finger
Placing reflex
Hold the infant upright under the arms, close to a table.
Let the dorsal “top” of foot touch the underside of the table.
Note flexing of hip and knee, followed by extension at the hip, to place foot on table
Reflex appears at 4 days after birth
Moro reflex
In a sitting position, allow the head to momentarily fall backwards, the infant will symmetrically extend and abduct their arms and open their hands
Galant reflex
Suspending the infant ventrally, supporting the anterior chest wall, applying pressure along the thoracic spine causes the infant to flex the trunk and swing their pelvis towards the stimulus
List of Problems for Preterm new-borns
1) Temperature control- Hypothermia, skin
2) Respiratory control
3) Circulation- Hypotension, Patent ductus arteriosus, anaemia
4) Gastrointestinal and nutrition- Necrotising enterocolitis, Nasogastric tube feeding and feeding intolerances
5) Brain, Metabolic, Infection, Eyes and Ears
Preterm babies- Hypothermia
Causes increases energy consumption which results in hypoxia, hypoglycaemia and failure to gain weight. Increases morbidity and mortality
Preterm babies- Skin
Infants have large surface area, skin is thin and permeable, little subcutaneous fat and can’t generate heat by shivering (they use fat thermogenesis to regulate temperature)
Preterm babies- Respiratory
1) Respiratory distress syndrome (RDS)- lungs are not fully developed
2) Pneumothorax- overinflation and bursting of alveoli from ventilator when air leaks into the pleural cavity
3) Apnoea, bradycardia and desaturation
Preterm baby- Respiratory Distress syndrome (RDS)
Surfactant deficiency which lowers surface tension leading to alveolar collapse and inadequate gas exchange
Preterm baby- Patent ductus arteriosus
The ductus arteriosus remains patent in many preterm infants causing oxygenated and deoxygenated blood to mix. Common in RDS. May be asymptomatic or cause apnoea, bradycardia and increased O2 requirements
Preterm baby- GI
1) Necrotising enterocolitis- caused by low blood flow/oxygen to the gut. The intestine becomes inflamed, can rupture and be necrotic. ‘Bubble like bowel.’
2) Feeding intolerance- struggles to meet TPN (total Parenteral nutrition) due to lactose intolerance and problems latching
Preterm babies- Brain
1) Haemorrhage
2) Post Haemorrhagic hydrocephalus
3) Ventricular dilation
4) Paraventricular leukomalacia
Preterm babies- Periventricular Leukomalacia
The white matter around the brain has decreased blood and oxygen causing it to soften. The white matter transmits messages from the nerve cells. Causes problems with movement and body function. Can generate new pathways to reduce the disability
Preterm babies- Ventricular dilation
An increased volume of cerebrospinal fluid (CSF) in the cerebral ventricles. Head measurements and USS detect it. Can resolve spontaneously or progress to hydrocephalus and require a ventriculoperitoneal shunt.
Preterm babies- Post haemorrhagic Hydrocephalus
Progressive ventriculomegaly caused by disturbances in CSF flow or absorption following intraventricular haemorrhage.
Metabolic problems for pre-term babies
1) Hypoglycaemia
2) Electrolyte disturbance- Hypocalcaemia
3) Osteopenia of prematurity- caused by calcium and phosphate deficiency. Causes low density in bones, poor bone growth and fractures
Preterm babies- eyes and ears
1) Retinopathy of prematurity- vascular proliferation can lead to retinal detachment, fibrosis and blindness
2) Hearing- less developed
Preterm babies- infection
Contributes to bronchopulmonary dysplasia, brain injury and disability
Uterine corpus
The top of the uterus. Primarily a muscular (smooth) structure with a small amount of connective tissue. Consists of longitudinal, circular and spiral fibres. Contraction of smooth muscle reduces size of lumen, allowing for delivery. The uterus is densely innervated, muscular contractions are mediated by gestational hormones not nerve fibres. Oxytocin produced in the posterior putuitary gland helps in contraction
Cervix
Primarily a fibrous structure with small amounts of smooth muscle, primarily a sphincter. May have an active role in labour. The amount of muscle fibres reduce as you go down the cervix
Uterine Quiescence
- HCG and CRH increase in concentration.
- This increases levels of Cyclic AMP
- Inhibits uterine contractility by preventing calcium mobilisation and MLCK activity.
- Decreased Myosin-actin cross bridge cycling, cells are relaxed
Effect of Connexin on labour
Prostaglandins promote uterine excitation by facilitating Connexin 43 (Cx43). This produces gap junction proteins which facilitates electrical connections between cells. Allows communication between cells. Towards labour more Cx43 is released. Signalling for contraction is passed from the top of the uterus down which allows coordination in contraction and increasing pressure, allowing delivery of the baby.
Initiation of labour
- Progesterone is blocked locally
- Decrease in gap junction protein and Prostaglandin inhibition
- A decrease in the Progesterone/Oestrogen ratio (oestrogen high). This causes upregulation in gap junction activity, Prostaglandin synthesis, Oxytocin receptors and local oxytocin synthesis.
- Decreased activity of cAMP pathway. This increases influx of calcium into the cells, there is increased release of intracellular calcium and increased MLCK activity
- Accelerated cervical remodelling- permits passing of conceptus through cervix
- Fetal adrenocortical activity signals to the mother
What causes the cervix to dilate
Pressure from the babies head
Cervical remodelling stages
There are 4 overlapping stages- Softening, Ripening/Dilation, Effacement and Postpartum repair
Cervical changes at the end of the third trimester
Collagen solubility increases. Collagen organisation decreases. The cervix takes on water and releases inflammatory hormones (Prostaglandins). There is increased pressure from the babies head on the cervix which causes dilation. Effacement is where the cervix shortens, can monitor the progress of labour by recording cervix dilation
Labour
Painful, regular contraction with the cervix dilated more then 3-4cm
Station- pregnancy
The position of the baby in the maternal pelvis
Bishop score
Assess’s changes to the cervix as it goes through labour. When the Bishop score is greater then 6 the womens water can get broken. If less then 6 prostaglandins are given to get the cervix ready for labour
Initiation of labour
activity may also stimulate labour.
Affect of Progesterone and Oestrogen in stimulating labour
Progesterone- decreases in gap junctions, decrease in Prostaglandin synthesis. Promotes quiescence.
Oestrogen- increases gap junctions, increases prostaglandin synthesis and oxytocin receptors. Increases local oxytocin production. Promotes excitation.
The pacemaker cells in the uterus
Are located in the cornual area. Flow of depolarisation goes from top to bottom, the uterine muscle is made of myometrium
First stage of labour
3cm to full dilation (10cm), latent phase and active phase. The latent phase is when women are contracting but not regularly, the latent phase can last for days. The active phase of labour is when women are contracting regularly and have dilated more then 3cm.
Second stage of labour
Full dilation to delivery of baby, passive phase and active phase. In the passive phase the uterus is contracting, and the baby is moving through the pelvis. Takes an hour or two. In the active phase the women pushes and uses their abdominal muscles.
Third stage of labour
Delivery of placenta and membranes, physiological and assisted. The release of oxytocin after delivery and from breast feeding helps delivery. It can also be assisted, which is where the women is given oxytocin and traction is applied to the cord in order to deliver the placenta
Widest parts in the pelvis
Pelvic inlet- the transverse diameter
Pelvic outlet- anteroposterior diameter
Position of the fetal head in the pelvis
The head enters the pelvic inlet in the Occipito-transverse position. The head rotates in the mid cavity and the head rotate 90 degrees to exit the pelvic outlet in the Occipito-anterior position.
Landmark for fetal descent
You measure the babies descent by measuring how many cm it is above the Ischial spine.
Moulding- pregnancy
When the fetal banes overlap
Attitude of the fetal skull
The attitude of the fetal skull refers to how flexed it is, is the chin on their chest or is it raised up (deflexed position). In normal attitude you can feel the posterior fontanelle and the Sagital suture. If the baby is deflexed, you can feel the anterior fontanelle, if its very deflexed you can feel the babies forehead. Rarely, you have a face presentation.
