Obs Flashcards
Services requirements for the provision of intrapartum care
Timely access to - obstetric, midwifery, neonatal / paediatric, anaesthetic, operating theatre, resuscitation services, ICU consultation, haematology, blood bank
Birth centres ideally placed within (or immediately adjacent to) an appropriately resourced 24h obstetric facility
If by virtue of remote location, on-site services cannot be provided, women should be informed of the limitations of services available and implications for intrapartum and postpartum care
- Formal systems must be in place to ensure safe and timely transfer if required
% of women developing peripartum complications requiring transfer in low risk population
Amongst women selected for low obstetric risk, ~25% will develop peripartum complications necessitating transfer to an obstetrician led services
RANZCOG recommended routine labour cares
VE is indicated for women admitted in apparent labour unless there are contraindications - Should be done within 4h to diagnose and assess the progress of labour.
Care is optimised where there is a 1:1 midwifery support in labour in collaborative service
Involve woman and her support person in management decisions
WHO recommends maternal observations be graphically displayed on a partogram to facilitate review of progress
HR, BP, RR, temp, contraction frequency, duration, intensity, abdominal palpation, VE findings, liquor colour / presence, FHR
Labour positioning
Women should be encouraged to ambulate freely according to comfort, where it does not compromise maternal and fetal observations in labour
- Cochrane 2013 - first stage of labour may be approx 1h 20m shorter for women who are upright or walk around (Better studies needed to validate these results)
Fluids and oral intake in labour
Some evidence that inadequate hydration may increase the length of labour and need for oxytocin augmentation
Encourage clear fluids and light diet in active phase of labour to minimise risk of aspiration pneumonitis
Antibiotics in labour
For prevention of GBS
For women at risk of chorioamnionitis or where other bacterial infection is suspected - e.g. fever >38 on one occasion or >37.4 on two occasions
Women with cardiac lesions susceptible to infective endocarditis
Impact of ARM on labour
Evidence that routine ARM shortens labour is largely lacking (Cochrane review 2009)
Risk of infection increased following rupture of membranes
ARM provides useful information on fetal wellbeing (liquor volume and colour)
Relative contraindications of ARM
HBV, HCV, HSV and HIV infection
- In order to minimise the risks of ascending infection
- In developing countries where incidence of HIV is high, amniotomy is developed in labour to reduce vertical transmission rates
Presenting part high and mobile
Monitoring labour progress
Most trials do 2 hourly cervical assessments
- Enables dystocia to be diagnosed and correctly early
- But added maternal discomfort of more frequent exams and potential for introducing infection
Compromise: 4 hourly VE
If full dilatation not clinically apparent after a woman is 9cm, further VE beneficial to confirm full dilatation or allow diagnosis of FTP if not fully
Second stage
- Reassessment at 2h in primigravida and 1h in multigravida
Definition of failure to progress
1st stage
Before established labour
No upper limit to the length of the ‘latent phase’ can be defined
Not uncommon for labour to stop and start before finally established
Recurrent or prolonged episodes of spurious labour may contribute to a legitimate decision for IOL in some women
Definition of failure to progress
1st stage
In established labour
- primigravida
10th centile for progress of cervical dilatation in labour is 0.9 cm/hour (primigravida)
Threshold at which slow cervical dilatation merits a recommendation for oxytocin:
- Individualised with an informed discussion with the woman
- Commonly 1cm/hr for most women in spontaneous labour
- May be as high as 1cm / 2hr in women prioritising low intervention
Definition of failure to progress
1st stage
In established labour
- multigravida
10th centile for progress of cervical dilatation is 1.2cm/hr (multigravida)
Caution for augmentation as increased risk of uterine rupture compared to primigravida
Definition of failure to progress
2nd stage
Progress in includes flexion, rotation and descent
Normal for primigravida = up to 2 hours
Normal for multigravida = up to 1 hours
When to consider episiotomy
Episiotomy should be considered where there is a high likelihood of severe laceration
- Soft tissue dystocia
- Requirement to accelerate birth of a compromised fetus
- Need to facilitate operative vaginal birth
- History of FGM
When to recommend physiological third stage
“Expectant” or “physiological” management cannot be recommended on the basis of evidence and is associated with approximately a two-fold increase in the incidence of postpartum haemorrhage and an increased risk of blood transfusion when compared with active management
Associations of delayed cord clamping in preterm infants
reduced risk of requiring transfusion, infection, NEC, and intraventricular haemorrhage
Associations of delayed cord clamping in term infants
increased haematocrit and reduced iron deficiency at 3-6 months of age
However increased risk of polycythaemia and jaundice
No clear evidence to guide practitioners regarding DCC in term infants
Infants are most likely to benefit if maternal iron stores are low, or in infants who will be exclusively breast fed without iron supplementation
Positioning for delayed cord clamping
~75% of available placental blood for transfusion is achieved in the first minute
Transfer of blood from placenta to newborn is facilitated by the infant being held below the level of the in situ placenta
- If infant 10cm above or below the placenta, transfusion is complete within 3 mins
- If 40cm below, transfusion time is shortened to 1 min
Routine newborn care
- Assess immediately as to the need for resuscitation
- Skin-to-skin should be facilitated providing there are no maternal or neonatal complications
- Apgar scores at 1 and 5 mins of age
- Regular neonatal obs - RR, HR, colour, tone, reflex irritability
- Observe for signs of respiratory distress - grunting, nasal flaring, intercostal retraction, tachypnoea, cyanosis
- IM vitamin K recommended
Routine maternal postpartum care
Regular maternal obs (HR, BP, temp)
Palpation of the uterine fundus to exclude atony
Inspection of the perineum to exclude excessive PP blood loss or development of vulval haematoma
Debriefing opportunities should be provided following an adverse outcome or experience that did not meet the expectations of the woman or her partner
Reasons for GDM screening
Evidence suggests benefit of reduced perinatal mortality in screening and treating GDM
RANZCOG GDM screening recommendation
75g 2h OGTT at 26-28 weeks
Earlier if high risk, and repeat at 24-28/40 if negative
Fasting: >/= 5.1 mmol/l
1h: >/- 10.0 mmol/l
2h: >/= 8.5 mmol/l
Polycose not recommended
GDM risk factors
Pre-pregnancy BMI >30
Previous macrosomic baby (>4.5kg or >90th centile)
Previous GDM / hyperglycaemia in pregnancyFHx of diabetes (1st degree relative or sister with GDM)
Minority ethnic family origin with high prevalence of diabetes
- Asian, Indian, Aboriginal, Torres Strait Islander, Pacific Islander, Maori, Middle Eastern, non-white African
PCOS
Medications - corticosteroids, antipsychotics
Maternal age >40
ADIPS diabetes mellitus in pregnancy diagnosis
Fasting >/= 7.0 mmol/l
2h or random >/= 11.1mmol/l
BSL targets on treatment
Fasting: <5.0 mmol/L
2 hours after meals: <6.7 mmol/L
If >10% of readings above targets, then reassess treatment
Iodine supplementation recommendation
RDI if pregnant, planning a pregnancy, or breast feeding: 150 micrograms/day
Definition of overt hypothyrodism
Overt hypothyroidism should be treated in pregnancy
- TSH >reference range with decreased T4, OR
- TSH >10mIU/L, irrespective of the level of FT4
RANZCOG recommendation for screening for hypothyroidism in pregnancy
No studies show thyroxine influences outcome
Routine screening and treatment not recommended
Test if symptoms of thyroid disease or personal Hx of thyroid disease
Main cause of hypothyroidism in NZ and Au
Hashimoto’s thyroiditis
Physiology of thyroid hormone production in pregnancy
Increase (2-fold) in serum thyroxine-binding globulin (TBG) –> increase in T4 and T3 but free T4 remains unchanged
Stimulation of the thyrotropin / TSH receptor by HCG
○ HCG has weak thyroid stimulating activity as structurally similar to TSH
○ Normal increase in HCG in early pregnancy may cause a small transient increase in free T4 with subsequent TSH suppression
T4 and T3 levels rise by approx 50% during the first half of pregnancy, plateau at 20/40, then new steady state is reach and overall production rate returns to prepregnancy rates
Fetus is reliant on transplacental transfer of maternal thyroid hormone (T4 and T3) until the fetal thyroid starts to become functional from 12/40
Iodine state during pregnancy
Relative maternal iodine deficiency
- 2-fold increase in renal loss (increased GFR + decreased reabsorption)
- Active transport of iodine to fetus
Uptake of plasma iodide into the thyroid is increased 3-fold
Insufficient dietary iodine –> cellular hyperplasia and goitre
Fetus and fully breastfed infant are dependent on maternal iodine for thyroid hormone synthesis
Risks of overt hypothyroidism
- Miscarriage
- PET
- Abruption
- PPH
- Anaemia
- Low birth weight
- Prematurity
- Perinatal mortality
- Stillbirth
- Impaired neurological development
- Low offspring IQ
Adequately treated hypothyroidism is not a/w any adverse maternal, fetal or neonatal complications
Pregnancy outcomes with subclinical hypothyroidism
Results for large cohorts and meta-analyses have not been consistent in demonstrating an association between SCH and adverse pregnancy outcomes
High quality prospective RCTs involving >100,000 women have not demonstrated any maternal or neonatal benefits from treatment of SCH with thyroxine
Associated with childhood developmental delay has not been confirmed in prospective cohort data
Incidence of obesity / overweight
~50% of women who become pregnant are either overweight or obese
Increased antenatal risks for obese women
normal BMI vs. BMI >40
Miscarriage GDM (1% vs. 7%) Fetal congenital abnormalities - E.g. increased risk of NTD - recommend high dose folate 5mg/day Stillbirth (perinatal death - 0.7% vs. 2%) PET (if BMI >35) HTN in pregnancy (2% vs. 10%) Thromboembolism (risk of PET > DVT) Abnormalities in fetal growth Obstructive sleep apnoea Preterm birth (7% vs. 11%) Maternal death
Increased intrapartum risks for obese women
IOL, prolonged labour and failure to progress Rate of instrumental delivery Failed instrumental delivery Shoulder dystocia Caesarean section (33% vs. 52%) Difficulties with fetal heart rate monitoring PPH Peripartum death
Increased anaesthetic risks for obese women
Difficulties with labour analgesia
Use of GA
Difficultly maintaining an adequate airway, failed intubation
Increased risk of need for ICU care post-op
Increased postpartum risks for obese women
Delayed wound healing and infection Thromboembolic disease Greater likelihood of needing support with breastfeeding establishment and continuation Postnatal depression Long term neonatal consequences - Neonatal body composition - Infant weight gain - Obesity
BMI definition and WHO categorisation
Weight in kg / square of height in metres
Underweight <18.5 Normal 18.5 - 24.99 Overweight 25 - 29.99 Obese class 1 30 - 34.99 Obese class 2 35 - 39.99 Obese class 3 >40
Fetal / neonatal risks with obesity
normal BMI vs. BMI >40
Neonatal mechanism ventilation (5 vs. 10%) PTB (7 vs. 11%) Macrosomia (11 vs. 21%) SGA customised (11 vs. 19%) LGA customised (11 vs. 16%)
Obesity - prepregnancy management
Weight management strategies:
- Dietary modification - consider referral to dietician
- Exercise
Discuss impact of obesity on fertility and pregnancy outcomes
Modest gain of 1-2 BMI units between pregnancies may increase the risk of gestational HTN, macrosomia, GDM
Medications or surgery for weight management are not recommended around the time of conception or during pregnancy
Advise supplement containing folate (high dose 5mg/day) and 150mcg iodine pre-conception
Address psychosocial concerns
Offer contraception to allow time for weight optimisation
Prior bariatric surgery
Require closer monitoring of their nutritional status and fetal growth
Current evidence suggests a positive outcome in reduction of maternal risks during pregnancy, such as GDM, but with an increase risk of FGR and stillbirth
Pre-pregnancy counselling
- Should be on lifelong vitamin supplementation
- Referral to dietician, especially if malabsorptive surgery - may require additional supplementation during pregnancy - vitamin B12, iron, folate, vitamin D, calcium
- Avoid pregnancy for 12-24 months after surgery and during the initial weight loss phase
Weight loss between pregnancies:
Reduces the risk of: ○ Stillbirth ○ Hypertensive complications ○ Fetal macrosomia Increases the chances of successful VBAC
Recommended weight gain in pregnancy
Underweight - 12.5 to 18kg
Normal weight - 11.5 to 16kg
Overweight - 6.8 to 11.3kg
Obese (includes all classes) - 5 to 9.1kg
Recommended weight gain for multiples
Normal weight 17 to 25kg
Overweight 14 to 23 kg
Obese (includes all classes) 11 to 19 kg
Timing of birth in obese women
- No universal consensus
- Observational data comparing outcomes before and after a protocol of delivery by 40/40 found a significant reduction in the risk of CS for obese women
Intrapartum management obese women
IV line on admission to labour ward
May need to confirm presentation with USS
Awareness of increased risk of shoulder dystocia and PPH
Operating theatre staff need to be altered regarding increased weight (usually >120kg)
To ensure adequate staffing and equipment available
Postpartum management obese women
Use of Rh(D) immunoglobulin
- Some evidence to suggest IM anti-D may be associated with increased risk of lack of effect in patients with a BMI >30 - however insufficient evidence to support a change in practice
Breastfeeding support
- Obesity is associated with lower rates of breastfeeding initiation and maintenance
- Breastfeeding has been associated with postpartum weight loss
Consider VTE prophylaxis
Weight management postpartum
Benefits of exercise during pregnancy
Physical benefits - fitness, prevention of excessive weight gain, lifelong benefits (reduced CVD, T2DM, some cancers)
Psychological wellbeing - reduced Sx of depression
No evidence detrimental to fetus or woman
Regular exercise during pregnancy has been a/w shorter and less complicated labour, and fewer neonatal complications (but inconclusive evidence)
Advice for Women with a high level of fitness doing regular vigorous exercise
No evidence of harm to pregnancy provided they adjust routine based on changes in comfort and tolerance
Athletes should be wary of excessive exertion - fetal wellbeing may be compromised about a certain (high) threshold of intensity - transient FHR decels and alterations in umbilical and uterine artery dopplers immediately post-exercise
Not known if these transient changes impact neonatal outcomes
Attention to adequate nutrition, hydration and avoiding overheating
Pregnancy is not a time for serious competition or aiming to reach peak lifetime fitness
Intensity of exercise recommendations in pregnancy
Pregnancy-specific heart rate zones equivalent to 60-80% of max aerobic capacity have been recommended for normal-weight women <20y - 140-155bpm 20-29y - 135-150bpm 30-39y - 130-145bpm >40y - 125-140bpm
If inactive overweight and obese, may be too high therefore aim for targets of 102-124bpm (if 20-29y) or 101-120bpm (if 30-39y)
Intensity considered moderate if can comfortably hold a conservation
Vigorous if need to pause for breath during conversation
General exercise advice for adults, apply to pregnancy
Active on most, preferably all days each week
Aim for 150-300 mins of moderate intensity exercise each week or 75-150 mins of vigorous exercise each week, or combination
Plus muscle strengthening exercises >2 days per week
Avoid prolonged sitting
Contraindications to exercise, irrespective of pregnancy
CVD
Poorly controlled asthma
Poorly controlled diabetes
Bone or joint problems
Additional medical and obstetric issues in pregnancy that may preclude exercise (but no literature, therefore individualise recommendation)
Persistent bleeding Placenta praevia PET PIH Indicators of increased risk of PTL - multiple pregnancy, rupture membranes, premature contractions, shortened cervical length FGR Poorly controlled thyroid disease Anaemia
Physiological changes of pregnancy that have implications on exercise
Increase in body weight - increased loading at the joints
Change in weight distribution - altered centre of gravity
Increase in ligament laxity - may have implications for the risk of injury
Decrease in BP
Increase in resting and submaximal HR
Increase in metabolic rate - avoid exercising at high temperatures and humidity
Enlarged uterus - improves venous return
Growing fetus
Weakened pelvic floor
Incidence of smoking in pregnancy
Australia: 1 in 10
NZ: 1 in 8
44% of Aboriginal and Torres Strait Islander
22% of Maori women
Smokers in pregnancy more likely to be younger and live in areas of SE disadvantage
3.8-fold increase in smoking cessation rate when compared to non-pregnant women
Of women who cease smoking during pregnancy, 50-70% will resume in the year PP
Pathogenesis of smoking and pregnancy outcomes
Smoking potentially disrupts the implantation process and interfering with the transformation of the uterine spiral arteries
Studies show thickening of the villous membrane of the placenta in smokers, lessening the ability of the placenta to function
Nicotine also impairs amnio acid transport across the placenta
Obstetric complications of smoking in pregnancy
Miscarriage
Ectopic pregnancy
Preterm labour and premature rupture of membranes – two-fold increase in the risk of preterm birth with smoking
Placental abruption – Two-fold increase in the risk
Placenta praevia – Relative risk 1.36
Pre-eclampsia – Of pregnancies that are complicated by severe pre-eclampsia, smoking is associated with increased rates of perinatal mortality, placental abruption and small for gestational age infants
Thrombotic risk
Anaesthetic risks and respiratory complications
Fetal complications of maternal smoking
Low birth weight (less than 2500g at birth)
Fetal anomalies
Perinatal death
Child and adult complications of maternal smoking
Sudden unexpected death in infancy syndrome (SUDI) Respiratory disease ENT and other infections Childhood cancers Nicotine dependence
Non-obstetric risks of smoking
increased rates of all- cause mortality, lung cancer, cervical pre-invasive disease and cancer, vulval cancer, bladder cancer, oropharyngeal cancer, breast cancer, cardiovascular disease, thromboembolic disease, chronic respiratory disease, reduced fertility, premature menopause and osteoporosis
NRT and pregnancy
NRT may be considered when a pregnant woman is otherwise unable to quit, and when the likelihood and benefits of cessation outweigh the risks of NRT and potential continued smoking
Intermittent-use forms (such as gum or spray) are preferred over continuous-delivery nicotine (patches)
Options for testing for inherited conditions
- Having child and testing after birth
- Conceiving naturally and having diagnostic testing during pregnancy (amniocentesis or CVS)
- IVF and testing embryos by preimplantation genetic diagnosis
- Using donor sperm, egg or embryo from unaffected individuals
- Adoption
- Not having children
If of Eastern European (Ashkenazi) Jewish descent, offer screening for:
- Tay Sachs disease
- Niemann Pick disease type A
- Fanconi anaemic group C
- Familial dysautonomia
- Bloom syndrome
- Canavan disease
Mucolipidosis type IV
Genetic carrier screening
- CF
- Spinal muscular atrophy
- Fragile X syndrome
Carrier frequency, frequency affected
Main clinical features
Cystic fibrosis
- 1 in 35
- 1 in 4925
Recurrent lung infections, malabsorption, shortened life span
Spinal muscular atrophy
- 1 in 50
- 1 in 9917
- Severe muscle weakness, death usually during childhood
Fragile X syndrome
- 1 in 332
- 1 in 7143
- Intellectual disability, autism
Australian study found that approximately 1 in 20 individuals accessing self-funded carrier screening were carriers of cystic fibrosis, spinal muscular atrophy and/or fragile X syndrome
three most common inherited genetic conditions for which prenatal diagnosis is currently performed:
thalassaemia
cystic fibrosis
fragile X syndrome.
Folic acid supplementation
Folic acid for a minimum of 1 month pre-conception and for first 3 months of pregnancy
- At least 0.4mg daily
If increased risk of NTD (anti-convulsant medication, pre-pregnancy diabetes, previous child or family history of NTD, BMI >35) –> 5mg daily
Luteal phase support for IVF
Luteal phase support with synthetic progestogens should be provided in IVF
- Associated with an improved live birth rate - Better results obtained with synthetic progestogens than micronized progesterone - No evidence to favour a specific route or duration of administration
Progesterone in early pregnancy
No evidence to suggest that giving progesterone supplementation to otherwise healthy women in the first trimester reduces the risk of spontaneous miscarriage
Progestogen supplementation until the second trimester in women presenting with threatened miscarriage may reduce the rate of spontaneous miscarriage
- Current evidence limited by methodological inconsistencies
Routine use of progestogens in those with recurrent spontaneous miscarriage does not improve pregnancy outcomes
Luteal phase support with synthetic progestogens should be provided in IVF
Progesterone use for recurrent spontaneous miscarriage
Routine use of progestogens in those with recurrent spontaneous miscarriage does not improve pregnancy outcomes
- PROMISE trial - no difference in the rate of miscarriage in women using vaginal micronized progesterone compared to placebo
- Significant heterogeneity in the clinical trials of progestogens
○ Possibility of a benefit cannot be excluded
