Transcript Antenatal Care - Department of Obstetrics & Gynaecology

Antenatal Care
Continuing Medical Education
Activities for Non-specialists
Dr TC Pun
27/2/2002
Antenatal Care
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Introduction
The first visit
Subsequent visits
Screening tests
Prenatal diagnosis and ultrasonogram
General advice
Summary
Introduction
Objectives
• education and information
• screening
• early identification of complications
• treatment of complications
Introduction
Patterns of routine antenatal care for low-risk
pregnancy
• assess the effects of antenatal care programmes for
low-risk women
• three trials, all conducted in developed countries,
evaluating the type of care provider
Cochrane Database Syst Rev 2001;4:CD000934
Introduction
• Giles 1992 – midwives versus obstetricians,
89 women, cost savings
• Tucker 1996 – general practitioners and
midwives versus shared care, 1765 women,
clinical effectiveness and satisfaction
• Turnbull 1996 – midwives versus shared
care, 1299 women, clinical effectiveness
and satisfaction
Introduction
• no difference for several outcome variables
including caesarean section, anaemia, urinary tract
infections and postpartum haemorrhage
• there is a trend to lower rate of preterm delivery,
antepartum haemorrhage, lower perinatal
mortality
• lack of recognition of fetal malpresentations
tended to be higher in this group
Cochrane Database Syst Rev 2001;4:CD000934
Introduction
• the midwife/general practitioner managed care
group had a statistically significant lower rate of
pregnancy induced hypertension and preeclampsia
• overall, it appears that satisfaction with
midwife/general practitioner managed care was
similar or higher (in some variables)
Cochrane Database Syst Rev 2001;4:CD000934
Introduction
• the midwife/general practitioner managed care
group had a statistically significant lower rate of
pregnancy induced hypertension and preeclampsia
• overall, it appears that satisfaction with
midwife/general practitioner managed care was
similar or higher (in some variables)
Cochrane Database Syst Rev 2001;4:CD000934
Introduction
Shared antenatal care between Family Health
Services and Hospital(Consultant) Services for
Low Risk Women
• decrease in workload to hospital clinics
• diagnosis of IUGR, malpresentation, pregnancy
induced hypertension improved
• number of NST, hospital admission, duration of
stay reduced
Chan FY et al 1993 Asia-Oceania J Obstet Gynaecol 19(3):291-298
Antenatal Care
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Introduction
The first visit
Subsequent visits
Screening tests
Prenatal diagnosis and ultrasonogram
General advice
Summary
The first visit
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timing
history
physical examination
risk determination
The first visit
Timing
• pregnancy test positive within a few days
after missed period
• early pregnancy complications like
miscarriages, ectopic pregnancy may be
first diagnosed in the clinic
Guidance on Ultrasound Procedures in Early
Pregnancy
Royal College of Radiologists, Royal College of Obstetricians and
Gynaecologists 1995
What should be reported
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number of sacs and mean gestation sac diameter
regularity and outline of the sac
presence of any haematoma
presence of a yolk sac
presence of a fetal pole
CRL
presence/absence of fetal heart movement
extrauterine observations should include the appearance of
the ovaries, the presence of any ovarian cyst or any findings
suggestive of an ectopic pregnancy
Miscarriage
Silent miscarriage
• sac diameter >20 mm with no evidence of
embryo or yolk sac
• CRL >6 mm with no evidence of cardiac
pulsation
• if sac diameter <20 mm or CRL < 6 mm,
repeat at least 1 week later
Miscarriage
Incomplete miscarriage
• thick irregular echoes in the midline of the
uterine cavity
• differential diagnosis: blood clots
Miscarriage
Complete miscarriage
• well defined regular endometrial line
• reliability: 98%
Ectopic pregnancy
• live embryo within a gestational sac in the
adnexa - gold standard
• poorly defined tubal ring
• presence of varying amount of fluid in the
Pouch of Douglas
Ectopic pregnancy
• may be normal in up to a quarter of patients
• enlarged but empty uterus with or without an
adnexal mass and/or fluid in the Pouch of
Douglas
• early diagnosis of normal intrauterine
pregnancy in transvaginal scan
• complex adnexal mass seen in 7% of patients
with normal intrauterine pregnancies
The first visit
Early Pregnancy Assessment Unit
• Streamline the management of women with
early pregnancy bleeding or pain
• Reduce the admission time
The first visit
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timing
history
physical examination
risk determination
The first visit
Is routine antenatal booking vaginal examination
necessary for reasons other than cervical cytology
if ultrasound examination is planned?
• 11622 consecutive case records abstracted
retrospectively
• If ultrasound is planned has few advantages
beyond the taking of a cervical smear
O’Donovan et al 1988 Br J Obstet Gynaecol 95:556-9
The first visit
Routine vaginal examination at antenatal
booking
• reasonable to reserve VE at the booking
antenatal clinic for women
– with a clinical indication, such as pain, bleeding
or vaginitis
– who have not had a satisfactory smear within
the past 3 years
Lancet 1988:432-3
The first visit
Pitfalls associated with cervical screening
during pregnancy
• sampling difficulty because of enlargement
of cervix, increased mucous secretion and
increased difficulty in viewing the
cervix(Cronje et al 2000 Int J Gynecol Obstet 68:19-23)
• cytological diagnostic pitfalls unique to this
population(Michael & Esfahani 1997 Diagn Cytopatho 17:99107)
The first visit
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timing
history
physical examination
risk determination
The first visit
Risk scoring system
• difficult to make quantitative estimates of
the exact risk associated with a given factor
• validity of adding weighed scores
• difficulty in definition of risk factors
• more predictive of outcome in second or
late pregnancies
The first visit
Risk scoring system
• both the positive(10-30%) and negative
predictive values of all scoring systems are
poor
• risk of increase in intervention
• may help to provide a minimum level of
care and attention in settings where these
are inadequate
The first visit
Modified McGill’s score
• with score 2 and above will be seen at TYH
• Demographic
• Obstetrical history
• Habits
• Growth
• Medical problems
• Current pregnancy
Modified McGill Score(1)
Demographic
• age <16(1)
• parity >5(1)
• weight <38 kg(1)
• weight >70 kg(1)
• unstable family(2)
Modified McGill Score(2)
Obstetric History
• perinatal death(2)
• SGA/LBW baby(2)
• gestational proteinuric hypertension(2)
• abruptio placentae(2)
• previous caesarean section(1)
• infertility(1)
• IGT/GDM(1)
Modified McGill Score(3)
Habits
• smoking(1)
• alcohol(1)
• drug addiction(2)
Growth
• discrepancy >2 weeks(2)
Modified McGill Score(4)
Medical problems
• recurrent UTI(2)
• impaired renal function(2)
• heart disease(2)
• essential hypertension(2)
• severe respiratory disease(2)
• diabetes mellitus(2)
• hyperthyroidism(2)
• jaundice(2)
• other major disease(2)
Modified McGill Score(5)
Current pregnancy
• recurrent vaginal bleeding > 12 weeks(2)
• anaemia <10 g(1), <9 g(2)
• hypertension(2)
• hydramnios(2)
• oligohydramnios(2)
• multiple pregnancy(2)
• Rh negative mother(2)
Antenatal Care
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Introduction
The first visit
Subsequent visits
Screening tests
Prenatal diagnosis and ultrasonogram
General advice
Summary
Subsequent visits
Patterns of routine antenatal care for low-risk
pregnancy
• in developed countries with well established
obstetrics services, small reductions in the number
of prenatal visits (equal or less than two visits) are
compatible with similar good perinatal outcomes
• women may be somehow disappointed with fewer
visits
Cochrane Database Syst Rev 2001;4:CD000934
Subsequent visits
Patterns of routine antenatal care for low-risk
pregnancy
• in developing countries, in which a proportionally
major reduction in the number of visits was
achieved, also supports this conclusion
• in the light of the available evidence, the four
antenatal care visits schedule tested in the largest
trials appears to be the minimum that should be
offered to low risk pregnant women.
Cochrane Database Syst Rev 2001;4:CD000934
First visit(booking)
TYH or MCHC
Risk score 0 to 1
Risk score >1
MCHC
TYH till delivery
30 week TYH
MCHC
36 week TYH
MCHC
40 week TYH
Subsequent visits
• every 4 week till 28 weeks
• every 2 week till 36 weeks
• every week till delivery
Subsequent visits
Fundal height for IUGR
• high specificity
• moderate sensitivity
• high negative predictive value
• only one randomized trial – ‘unwise to
abandon’(Cochrane Database Syst Rev. 2000;(2):CD000944)
Antenatal Care
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Introduction
The first visit
Subsequent visits
Screening tests
Prenatal diagnosis and ultrasonogram
General advice
Summary
Screening tests
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Hb – at booking and at 30-32 weeks
Rh – for isoimmunisation
rubella immune status
VDRL
HbsAg status
cervical smear
MCV
Maternal MCV
at booking
>80 fl
<= 80 fl
no action
husband called
back for MCV
Paternal MCV
>80 fl
Paternal MCV
<= 80 fl
cause of maternal
microcytosis
Fe and Hb study
Fe and Hb study
Fe
deficiency
normal
Fe
Fe therapy
repeat Fe later
thalassaemia
Screening tests
HIV
• opt-out screening since 1/9/2001
• information to be given
– HIV is the virus causing AIDS but HIV
infection may not lead to AIDS till years later
– positive result means infection; although there
is no cure but treatment can delay the onset of
AIDS
Screening tests
HIV
• information to be given
– mother to baby transmission occurs in 15-40%
and treatment can reduce the chance
– window period
– confidentiality
Screening tests
Results of the first 3 months
• 10238 tests were performed
• 4% chose not to be tested
• 6 positive results
Screening tests
Biochemical screening for Down’s Syndrome
• 97% of Down syndrome pregnancies are
sporadic
• age as screening test is not sensitive
• AFP and HCG for screening between 15-20
weeks improves the sensitivity(screen
positive rate of 5% or less, sensitivity of 6070%)
Screening tests
Biochemical screening for Down’s Syndrome
• value of addition of oestriol controversial
• role of nuchal lucency measurement
Screening tests
Gestational diabetes
• increase in perinatal mortality associated with
abnormal glucose tolerance appears to be
predicted as much by the indication for glucose
tolerance testing
• no convincing evidence that treatment of women
with an abnormal glucose tolerance test will
reduce perinatal mortality or morbidity
• no benefit has been established for glucose
screening
Screening tests
Gestational glucose tolerance screening at
TYH
• 75 g OGTT for those with risk factors
• spot glucose screening using cut off of more
than 5 mmol/l(more than) or 5.8
mmol/l(less than 2 hours after meal) for
those without risk factors
Screening tests
Urine culture
• reduce the risk of pyelonephritis if followed
by single dose therapy
• if culture not available, can be screened by a
urine dipstick multiple test for leucocyte
esterase and nitrite
Screening tests
Other screening tests
• Group B streptococcus
• Bacterial vaginosis
• ……
Antenatal Care
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Introduction
The first visit
Subsequent visits
Screening tests
Prenatal diagnosis and ultrasonogram
General advice
Summary
Prenatal diagnosis and
ultrasonogram
Referral to Prenatal Diagnosis and Counselling
Department
• advanced maternal age
• hereditary disease
• maternal exposure to teratogen
• previous abnormal children
• abnormal screening test
• suspected fetal abnormality
Prenatal diagnosis and
ultrasonogram
Possible merits of USG
• confirmation of the term date if performed
before 24 weeks
• assessment of term date when history is
unreliable
• detection of malformation
• detection of multiple pregnancy
Prenatal diagnosis and
ultrasonogram
Possible merits of USG
• placenta localisation
• sex of child
• others: some chromosome disorders, fetal
death, ectopic pregnancy, molar pregnancy
Prenatal diagnosis and
ultrasonogram
• screening does not improve the outcome of
pregnancy in terms of live births and
morbidity
• reduced incidence of induction of labour for
apparent post-term pregnancy
• twin pregnancies are detected earlier
• no clear evidence of harm ?increase in left
handedness
Antenatal Care
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Introduction
The first visit
Subsequent visits
Screening tests
Prenatal diagnosis and ultrasonogram
General advice
Summary
General advice
Major difference of RDA in pregnancy
• Calorie 150 kcal more in first trimester, 350
kcal more subsequently
• Protein 60g (44 g in non-pregnant)
• Folate 400 ug (180 ug in non-pregnant)
• Calcium 1200 mg (800 mg in non-pregnant)
• Iron 30 mg (15 mg in non-pregnant)
General advice
236 ml of milk contains
• 146.3 kcal
• 7.3 g protein
• Ca 259.6 mg
General advice
Iron and folate supplement
• clear evidence of an improvement in
haematological indices in women receiving
routine iron and folate supplementation in
pregnancy
• no conclusions can be drawn in terms of any
effects, beneficial or harmful, on clinical outcomes
for mother and baby as available data are often
from single small trials
(Cochrane Database Syst Rev 2002 Issue 1)
General advice
Iron and folate supplement
• at present, there is no evidence to advise
against a policy of routine iron and folate
supplementation in pregnancy
• routine iron and folate supplementation
could be warranted in populations in which
iron and folate deficiency is common.
(Cochrane Database Syst Rev 2002 Issue 1)
General advice
Incidence of anaemia
• 1990-1992 7.5% of patients with anaemia
• 54.8% had thalassaemia
• 42.6% classified as iron deficiency
(Lao & Pun 1996 Eur J OG Reprod Bio 68: 53-8)
General advice
Effect of folate supplement on pregnant
women with beta-thalassaemia minor
• Patients who received 5 mg folate daily
showed a significant increase in predelivery
Hb concentration
• Does not influence obstetric performance
(Leung et al 1989 Eur J OG Reprod Bio 33:209-13)
General advice
Smoking
• 5-15 minutes Office based intervention
increased cessation by 30-70%
• use of nicotine replacement products or
other pharmaceuticals as smoking cessation
aids during pregnancy has not been
sufficiently evaluated
(ACOG Education Bulletin #260)
General advice
Alcohol
• known teratogen
• heavy maternal use is related to fetal
alcohol syndrome
• moderate use may be related to spontaneous
abortions and to developmental and
behavioural dysfunction in the infant
General advice
Alcohol
• should limit to no more than 2 drinks daily(1
ounce or 30 ml of absolute alcohol) (Am Council on
Science and Health)
• a drink- 12 ounces(350 ml) of regular beer (150
calories) 5 ounces(150 ml) of wine (100 calories)
1.5 ounces(45 ml) of 80-proof distilled spirits (100
calories)
• safest course is abstinence
General advice
Coffee
• amount of caffeine in commonly used
beverages varies widely
– caffeinated coffee (66-146 mg)
– non-herbal tea(20-46 mg)
– caffeinated soft drinks (47 mg)
General advice
Coffee
• when used in moderation, no association
with congenital malformation, miscarriage,
preterm birth and low birth weight has been
proven
• high dose may be associated with
miscarriage, difficulty in becoming
pregnant and infertility
General advice
Seat belt
• above and below the bump, not over it
• three-point seat belts should be worn
throughout
• if necessary, the seat should be adjusted
(Why mothers die: a report on confidential enquiries into
maternal deaths in the UK 1997-1999)
http://www.cemd.org.uk/reports/c14.pdf
General advice
Air bag
• potential concern: the proximity of the gravid
uterus to the deploying air bag creates an
increased risk of fetal death
• benefits appear to outweigh risks in pregnant
women
• further study be done
(National Conference on Medical Indications for Air Bag Disconnection
1997)
http://www.emsvillage.com/village_library/article2.cfm?id=9
General advice
Air travel
• can fly safely up to 36 weeks(ACOG Committee Opinion
2001 #264)
• prevention of deep vein thrombosis
– general – isometric calf exercise, walking around, drink
water/juices/soft drinks, avoid alcohol and caffeine
– ?compression stockings if over 3 hours
(RCOG Scientific Advisory Committee 2001 #1)
General advice
Exercise
• 30 minutes or more of moderate exercise a
day should occur on most, if not all, days of
the week
• pregnant women also can adopt this
recommendation
(ACOG Committee Opinion 2002 #267)
General advice
Warning signs to terminate exercise while pregnant
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vaginal bleeding
dyspnea prior to exertion
dizziness
headache
chest pain
muscle weakness
calf pain or swelling
preterm labour
decreased fetal movement
amniotic fluid leakage
(ACOG Committee Opinion 2002 #267)
General advice
Exercise
• avoid motionless standing
• avoid sports with high potential for contact,
risk of falling, abdominal trauma, scuba
diving
• avoid supine position after first trimester
(ACOG Committee Opinion 2002 #267)
General advice
Work
• most jobs cause no increased hazard to the
mother or baby
• should be warned that if any complications
arise she must be able to leave work easily
• specific hazards – chemical, physical,
biological, others
(Chamberlain & Morgan 2002 in ABC of Antenatal Care)
General advice
Umbilical cord blood banking
• routine directed commercial cord blood collection
and stem-cell storage cannot be recommended
because of insufficient scientific base to support
such practice and the attendant logistic problems
of collection
• collection of altruistic donations and directed
donations for at risk families remain acceptable
procedures
(RCOG Scientific Advisory Committee 2001 #2)
Summary(1)
• family physicians should be involved in the
provision of antenatal care in low risk patients
• early pregnancy complications are more
commonly seen in primary care settings
• vaginal examination is not necessarily an integral
part of antenatal care
• fundal height is probably useful for detecting
IUGR
Summary(2)
• MCV and HIV tests are integral part of
antenatal screening test
• urine culture and biochemical screening can
be considered
• routine USG is useful in confirming the
gestational age and detecting multiple
pregnancy
Summary(3)
• additional 1-2 servings of milk should cover
the additional nutritional need of pregnancy
• routine prescription of iron and folate is a
reasonable practice
• additional folate supplement in thalassaemic
patients can reduce anaemia
• seat belt should be worn and air bag should
not be deactivated
Summary(4)
• usual exercise and work should not be
affected
• commercial cord blood collection and stemcell storage should not be recommended
Thank You!
Dr TC Pun
Tsan Yuk Hospital
Hong Kong