46 weeks of care –
sharing the patient journey through
pregnancy to 6 weeks post-partum
3rd November 2012
CHWC
The Canberra Hospital
Management of Obesity
in pregnancy
Steven Adair
Clinical Director O&G
CHWC, Canberra
Definitions
• BMI is the most commonly used indicator of
maternal weight (wt in kg/height in m2 )
• The usual categories are;
–
–
–
–
–
–
BMI 18.5 to 25 is normal weight range
BMI > 25 is overweight
BMI > 30 is obese
BMI > 35 is severe obesity
BMI > 40 is morbid obesity
BMI > 50 is extreme morbid obesity
Demographics
• One and a half billion adults worldwide are
overweight, and half a billion are obese
• Australia now has one of the highest rates of
overweight and obesity in the world
• Latest figures show that 21.7% of the
population is obese (60% are overweight)
• One in four Australian women are obese
Extreme Morbid Obesity
BMI: 71.8
AMOSS conditions 2010-2011
•
•
•
•
•
•
•
Antenatal pulmonary embolism
Amniotic fluid embolism
Eclampsia
Extreme morbid obesity (BMI >50)
Influenza A with admission to ICU
Peripartum hysterectomy
Placenta accreta
AMOSS surveillance 2010–2011
2010–2011 conditions
Number of
cases
Rate/1000
births
a95%
Maternal
deaths
% case
fatality
Morbid obesity BMI>50
370
2.68
2.49, 2.87
0
-
Influenza A ICU admission
36
0.19
0.14, 0.28
0
-
Amniotic fluid embolism
36
0.04
0.03, 0.06
5
14
Antenatal pulmonary
embolism
104
0.12
0.10, 0.14
0
-
Eclampsia
135
0.22
0.18, 0.26
0
-
Placenta accreta
285
0.42
0.38, 0.48
2
1
Peripartum hysterectomy
399
0.60
0.55, 0.65
3
1
CI
AMOSS Surveillance
• Data collection was suspended after 10 months due
to data overload
• 357 cases reported from > 170,000 births
(approximately 2 per 1000)
• 179 (53.7%) had a c/section
– Elective c/section 94 (53%)
– Emergency c/section 85 (47%)
BMI in pregnancy
• Pre-pregnancy BMI is
not routinely collected
(studies use maternal
recall)
• End of pregnancy BMI is
altered by weight gain in
pregnancy
• BMI at booking visit
(often 12 to 20 wks) is
accessible data
2011 figures from The Canberra Hospital
• Many units in the Canberra region will transfer
women with BMI > 35 for birth
– In 2011 (2577 / 2805)
• BMI > 30 in 515 20%
• BMI > 35 in 230 9%
• BMI > 45 in 28 1%
(43 per month)
(20 per month)
(>2 per month)
• This means that each week there are 2 or 3
women birthing with morbid obesity
Recent Evidence
October 2012
• Editorial:
“The increasing impact of maternal
obesity on obstetric practice.”
• Pre-pregnancy BMI
• Intra-pregnancy weight gain
• IOM guidelines for weight gain
in 1st T of <1.5kg in obese.
Pregnancy Consequences
• Congenital anomalies
• Diabetes
• Stillbirth
Congenital Anomalies
• The data showing an increased risk of
congenital anomalies are inconsistent
• Possible explanations include;
– Relative folate deficiency
– Higher rates of undiagnosed type 2 DM
– Later diagnosis of severe anomalies may increase
birth prevalence
Gestational Diabetes
• Clear association
between BMI and risk
of GDM
• Women with BMI > 40
have a 10% risk
• Strongly linked to need
for insulin, fetal
macrosomia and c/s
10
9
8
7
6
5
4
3
2
1
0
<18.5
>25
>35
GDM%
aOR
Stillbirth
• Maternal overweight & obesity are very
significant modifiable risk factors for stillbirth
• The top PARs (Population Attributable Risk) for
stillbirth at >22 weeks in HIC are;
– Overweight/obesity (7.7 to 17.6%)
– Maternal age (7.5 to 11.1%)
– Smoking (3.9 to 6.2%)
Flenady et al (2011), Major risk factors for stillbirth in high-income countries: a
systematic review and meta-analysis Lancet 377, 1331-1340
Association of overweight and obesity with
stillbirth in High Income Countries (HIC)
Flenady et al (2011), Major risk factors for stillbirth in high-income countries: a
systematic review and meta-analysis Lancet 377, 1331-1340
Birth Consequences
• Timing of birth?
• Place of birth?
• Mode of birth?
Place of birth
• Many low-risk units will preferentially transfer
women with BMI > 35
– Anaesthetic risks
– Surgical risks
• This policy causes much maternal distress and
family dislocation
• Possible to triage based on fetal size and
previous obstetric history
Mode of birth
• All studies show higher c/section rates in
obese women
• Why is this so?
– Bigger babies
– Less efficient uterine activity
– More iatrogenic intervention?
Birth outcomes TCH 2011
Caesarean Section Rate (26.1%)
BMI >35
40.43%
BMI >45
42.85%
Implications for Maternity Services
• Increased workload in relation to GDM
• Special clinics/models of care for women with
high BMI
– Dietitian/psychologist/physiotherapist
• Protocols for managing surgical and
anaesthetic risks for women with BMI > 50
• Need for transfer for women deemed to be at
higher risk
Clinical Practice Guidelines
Antenatal Care – Module 1
Draft for AHMAC
February 2012
Clinical Practice Guidelines
Antenatal Care – Module 1
Draft for AHMAC
February 2012
7.2 Weight and body mass index
7.2 Weight and body mass index
• ‘Pre-pregnancy weight and weight gain during
pregnancy are important determinants of both
mother and baby.’
• Measure women’s weight and height at the first antenatal
visit and calculate their BMI. (B)
• Repeated weighting during pregnancy should be confined to
circumstances that are likely to influence clinical
management. (pp)
• Give women advice about appropriate weight gain during
pregnancy in relation to their BMI. (B)
• Taking a respectful, positive and supportive approach and
providing information about healthy eating and physical
activity in an appropriate format may assist discussion of
weight management. (pp)
7.2 Weight and body mass index
• ‘Pre-pregnancy weight and weight gain during pregnancy are
important determinants of both mother and baby.’
• Measure women’s weight and height at the first
antenatal visit and calculate their BMI. (B)
• Repeated weighting during pregnancy should be confined to
circumstances that are likely to influence clinical
management. (pp)
• Give women advice about appropriate weight gain during
pregnancy in relation to their BMI. (B)
• Taking a respectful, positive and supportive approach and
providing information about healthy eating and physical
activity in an appropriate format may assist discussion of
weight management. (pp)
7.2 Weight and body mass index
• ‘Pre-pregnancy weight and weight gain during pregnancy are
important determinants of both mother and baby.’
• Measure women’s weight and height at the first antenatal
visit and calculate their BMI. (B)
• Repeated weighting during pregnancy should be confined to
circumstances that are likely to influence clinical
management. (pp)
• Give women advice about appropriate weight gain during
pregnancy in relation to their BMI. (B)
• Taking a respectful, positive and supportive approach and
providing information about healthy eating and physical
activity in an appropriate format may assist discussion of
weight management. (pp)
7.2 Weight and body mass index
• ‘Pre-pregnancy weight and weight gain during pregnancy are
important determinants of both mother and baby.’
• Measure women’s weight and height at the first antenatal
visit and calculate their BMI. (B)
• Repeated weighting during pregnancy should be confined to
circumstances that are likely to influence clinical
management. (pp)
• Give women advice about appropriate weight gain
during pregnancy in relation to their BMI. (B)
• Taking a respectful, positive and supportive approach and
providing information about healthy eating and physical
activity in an appropriate format may assist discussion of
weight management. (pp)
7.2 Weight and body mass index
• ‘Pre-pregnancy weight and weight gain during pregnancy are
important determinants of both mother and baby.’
• Measure women’s weight and height at the first antenatal
visit and calculate their BMI. (B)
• Repeated weighting during pregnancy should be confined to
circumstances that are likely to influence clinical
management. (pp)
• Give women advice about appropriate weight gain during
pregnancy in relation to their BMI. (B)
• Taking a respectful, positive and supportive approach and
providing information about healthy eating and physical
activity in an appropriate format may assist discussion of
weight management. (pp)
7.2 Weight and body mass index
• ‘Pre-pregnancy weight and weight gain during
pregnancy are important determinants of both
mother and baby.’
• Measure women’s weight and height at the first
antenatal visit and calculate their BMI. (B)
• Repeated weighting during pregnancy should be confined to
circumstances that are likely to influence clinical
management. (pp)
• Give women advice about appropriate weight gain
during pregnancy in relation to their BMI. (B)
• Taking a respectful, postiive and supportive approach and
providing information about healthy eating and physical
activity in an appropriate format may assist discussion of
weight management. (pp)
Possible interventions
• Pre-pregnancy counselling
– many pregnancies are unplanned
– sub-fertility in overweight/obese women
– assisted reproduction technology (ART)
• Reducing weight gain in pregnancy
– dietician involvement and routine weighing
• Maximising inter-pregnancy weight loss
– breastfeeding
Possible birth interventions
• There are a number of ‘birth choices’ for
overweight and obese women that are yet to
be properly trialled
– Early v standard timing of birth
– Spontaneous v induced labour
– Emergency v elective caesarean section?
Timing of birth
• There is pressure to intervene due to the
increased risk of stillbirth, and GDM
• Does more intervention lead to greater
complications?
• How should standard IOL policies be modified
by maternal BMI?
Eat Less
&
Do More!
Placental Responses to Obesity and
Pregnancy Outcomes Study
PROPOS
Principal InvestigatorsProf Christopher Nolan Prof Jane Dahlstrom
Prof David Ellwood A/Prof Alison Kent
PROPOS
• The PROPOS study will evaluate the
effects of obesity on placental
structure and function and how this
affects pregnancy outcomes
PROPOS
For the women it involves-
•Recruitment if eligible prior to 12 weeks gestation
•4 weekly visits to TCH from 12 weeks gestation
•Dietary and exercise advice
•Fetal Medicine Unit ultrasound assessments at 12, 20, 28 and 36
weeks gestation
•Maternal anthropometric/ metabolic assessments at 16, 24, 32 weeks
gestation
•Maternal and cord blood taken at delivery
•Detailed study of placenta (appearance, histology, metabolism, gene
expression)
•Neonatal anthropometric/ metabolic assessment and review at 12
months
•All maternal and fetal/neonatal adverse outcomes will be carefully
documented
PROPOS
Dyslipidaemia
Systemic Hypertension
Hyperglycaemia
Maternal
obesity
Inflammation
Harmful placental
adaptations
Abnormal adipokines
Other factors
Altered
placental function
and/or
structure
Beneficial placental
adaptations
38
PROPOS
Selection Criteria for PROPOS Subjects
Inclusion criteria study A:
• Age 20-38
• <12 weeks gestation
• Previous C-section
• Lean BMI 18.5-25.0
• Obese BMI  30.0
Inclusion criteria study B:
•Age 20-38
•<12 weeks gestation
•Nulliparous
•Obese BMI  30.0
Exclusion Criteria:
• Pre-existing diabetes, chronic hypertension, active smokers,
delivering at hospital other than TCH, induced conception
For further information or patient referral, please contact:
Endocrinology Unit, The Canberra Hospital on 6244 2228 or
Anthea Oon, Research Coordinator, Clinical Trials Unit 6244 3687
Eat Less
&
Do More!