obesity in pregnancy: is it a big problem? joseph r. biggio, m.d
TRANSCRIPT
Obesity in Pregnancy: Is it a Big Problem?
Joseph R. Biggio, M.D.
Objectives
• Become familiar with the physiologic alterations in obese pregnant women
• Understand the medical and obstetric complications associated with obesity in pregnancy
• Become familiar with long-term consequences of maternal obesity for the woman and her offspring
• Discuss risk-reducing strategies for obesity-related complications
Obesity
• Major medical and public health problem
• Significant morbidity and mortality
• Health care expenditures: • By 2030, 16-18% of all healthcare
expenditures related
Wang et al, Obesity 2008
2000
Obesity Trends* Among U.S. AdultsBRFSS, 1990, 2000, 2010
(*BMI 30, or about 30 lbs. overweight for 5’4” person)
2010
1990
No Data <10% 10%–14% 15%–19% 20%–24% 25%–29% ≥30%
15%–<20% 20%–<25% 25%–<30% 30%–<35% ≥35%
Obesity Among U.S. Adults BRFSS, 2013
CA
MT
ID
NVUT
AZNM
WY
WA
OR
CO
NE
ND
SD
TX
OK
KS
IA
MN
AR
MO
LA
MI
IN
KY
ILOH
TN
MS AL
WI
PA
WV
SC
VA
NC
GA
FL
NY
VT
ME
HI
AK
NHMARICTNJDEMDDC
PRGUAM
Obesity in Women
NHANES, Health E-Stat, Fryar et al, CDC NCHS, Sept 2014
BMI 2001-02 2011-1225-29.9 28.2 29.730-39.9 33.2 36.1>40 6.5 8.3
Obesity: Race/ethnicity effect
NHANES, Health E-Stat, Fryar et al, CDC NCHS, Sept 2014; NCVS, Flegal et al, 2010
2011-12Non-Hispanic White 32.8Non-Hispanic Black 56.6Asian 11.4Hispanic 44.4
• 75% of AA women BMI >25
Economic Costs—Medical Care• Increased utilization of resources
• Prenatal visits• Ultrasounds and fetal surveillance• Medications dispensed
• Increased• Comorbid conditions• Hospitalizations• Prolonged hospital stays• Maternal and neonatal ICU admissions
• Adds approximately $5.4-6 billion annually in healthcare cost in UK
Chu et al., NEJM, 2008; Heslehurst, Obes Rev 2008; Dennison et al., BJOG. 2009
Physiologic Changes: Cardiovascular
• Blood volume, Cardiac output increase in proportion to fat and tissue mass• CO increase 30-35 ml/min per 100 gm fat
• Diminished progesterone-induced vascular compliance• Increase risk for LV hypertrophy• Intimal hyperplasia and medial thickening
Veille JC et al, AJOG 1994; Perlow J, Obstetric Intensive Care Manual, 2003
Physiologic Changes: Pulmonary
PO2, chest wall/lung compliance• 50% lower compliance than non-obese• Work of breathing 3x higher than normal
• Risk for sleep apnea• Pulmonary hypertension
Juvin et al, Anesth Analges, 2003; Perlow J, Obstetric Intensive Care Manual, 2003
OSA, Co-morbidities & Outcomes
CHTN Diabetes Asthma05
1015202530354045
44
3033
11 9 93 1
8
OSAObeseNormal Wt
Louis et al, AJOG 2010; 202(3):261
Pre-E <37 wk <32 wk Cesarean0
10
20
30
40
50
60
19
30
12
58
11 10
1
40
712
4
15
Antenatal Complications
• Infertility
• Spontaneous Abortion
• Congenital Malformations
• Perinatal Mortality
Infertility• Fecundity reduced
• Overweight 8%• Obese 18%
• Possible Etiologies• HPO axis disruption• Increased leptin• Insulin resistance with androgen, SHBG• fat, estrone• Endometrial abnormalities
Gesink et al, Hum Repro, 2007; Pasquali et al, Hum Repro Update, 2003; Haslam, Lancet, 2005
Spontaneous Abortion
• Increased loss rateOR 1.7 (1.3 – 2.3)
• After ovulation induction: OR 5.1 (1.8 – 14.8)
• ? Related to estrogen and luteal phase defect with progesterone
• ? diabetesMetwally et al, Fertil Ster, 2008
Congenital Anomaly and Obesity
• Multiple studies demonstrate increased risk• Multiple different types involved
• Dose-response relationship
• Undiagnosed diabetes suggested as potential contributor
Stothard et al, 2009; Shaw et al, 2008; Biggio et al, 2010
Blomberg & Kallen, 2010
Obesity and Anomalies
BMI ≥30NTD 2.04 (1.5-2.7)Cardiac 1.17 (1.1-2.2)Cleft 1.26 (1.1-2.0)Anal atresia 1.87 (1.4-2.5)Cystic kidney 1.40 (1.0-1.9)Omphalocele 2.03 (1.4-2.9)
BMI 30-34.9 35-39.9 ≥40
NTD 1.8 (1.3-2.5) 2.1 (1.1-3.5) 4.1 (1.9-7.8)
Cardiac 1.1 (1.0-1.2) 1.3 (1.1-1.4) 1.5(1.2-1.8)
Cleft 1.1 (0.9-1.3) 1.6 (1.3-2.1) 1.9 (1.3-2.9)
Anal atresia 1.8 (1.3-2.4) 1.5 (0.7-2.6) 3.7 (1.7-7.1)
Dose-Dependent
Blomberg & Kallen, 2010
Perinatal Mortality
0
1
2
3
4
5
Adju
sted
OR*
Cedergren – Obstet Gynecol 2004
19.8 – 26.0 29.1 – 35.0 35.1 – 40.0
BMI (kg/m2)
> 40.0
Stillbirth after 28 weeksEarly Neonatal Death
Perinatal Complications
• Preeclampsia
• Preterm birth
• Gestational diabetes
• Fetal macrosomia
• Fetal Demise
Pre-eclampsia
0
1
2
3
4
5
Adju
sted
OR*
Cedergren – Obstet Gynecol 2004
19.8 – 26.0 29.1 – 35.0 35.1 – 40.0
BMI (kg/m2)
> 40.0
Pre-eclampsia
• Each BMI unit increases risk 0.5%• Normal weight 2-4%• BMI ≥ 30 8-12%
• Similar magnitude regardless of race
Bodnar et al, Epidemiology, 2007
O’Brien et al, Epidemiology, 2003
Preterm Birth
• Conflicting literature• Multiple studies suggest protective against SPTB• Obesity characterized by inflammation
• Large meta-analysis of overweight and obese women• PTB <37 wk RR 1.06 (0.87 – 1.3)• SPTB RR 0.93 (0.85 – 1.01)• Indicated PTB RR 1.30 (1.23 – 1.37)
McDonald et al, 2010
Preterm Birth
• Swedish Birth Registry• SPTB
• Extremely PTB (22-27 wk) increases with BMI
• No increase in 28-31 or 32-36 wk
• Indicated PTB• Increased for all GA and all BMI >25• Highest risk BMI ≥40
BMI 25-<30 30-<35 35-<40 ≥401.12 (1.0-1.2) 1.22 (1.04-1.44) 1.73 (1.35-2.21) 2.71 (1.95-3.78)
Cnattingius et al, 2013
Gestational Diabetes
0
1
2
3
4
Odd
s Ra
tio
Sebire 2001
20 - 24.9 25 – 29.9
BMI (kg/m2)
>30
LGA/Macrosomia
0
1
2
3
4
Odd
s Ra
tio
Cedergren, Obstet Gynecol, 2004
29.1 – 35 35.1 – 40
BMI (kg/m2)
>40
• Mechanism unclear• Meta-analysis
• Overweight 1.5 (1.1 – 1.9)• Obese 2.1 (1.6 – 2.7)
• Translate to 1.4% SB rate
• Ethnic disparity in risk• Caucasian 1.4 (1.3 – 1.5)• AA 1.9 (1.7 – 2.1)
Chu et al, 2007
Salihu et al, 2007
Fetal Demise
Fetal Demise
• Stillbirth Collaborative Network• Obesity/overweight independently associated • aOR 1.72 (1.22 – 2.43)
• Danish Birth Cohort• 28-36 wk HR 2.1 (1.0 – 4.4)• 37-39 wk HR 3.5 (1.9 – 6.4)• ≥40 wk HR 4.6 (1.6 –
1.3)Stillbirth Network, 2011; Nohr et al,
2005
Peripartum Complications
• Labor induction
• Cesarean delivery
• Labor dysfunction
• Postpartum hemorrhage
• Shoulder dystocia
• Wound complications
• Neonatal complications
Induction of Labor
BMI 29.1-35 BMI 35.1-40 BMI > 400
0.5
1
1.5
2
2.5
Cedergren, Obstet Gyncecol, 2004
Odd
s ra
tio
Cesarean Delivery
BMI 29.1-35 BMI 35.1-40 BMI > 400
0.5
1
1.5
2
2.5
3
Cedergren, Obstet Gyncecol, 2004
Odd
s ra
tio
Cesarean: Wound Infections
0
1
2
3
4
5
100 – 199 lb 200 – 299 lb ≥ 300 lb< 100 lb
% W
omen
with
Wou
nd In
fecti
ons
NICHD MFMU C/S Registry 2002
p < 0.0001
C/S Contributors
• Inductions• Co-morbidities• Presumed macrosomia
• Fetal decompensation intrapartum• Dysfunctional labor
• 3.5X rate of CS in first stage of labor• Increased need for augmentation and higher
doses of oxytocin• In vitro—poor myometrial contractility
Zhang et al, BJOG, 2007
Postpartum Hemorrhage
BMI 29.1-35 BMI 35.1-40 BMI > 400
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
Cedergren, Obstet Gyncecol, 2004
Odd
s ra
tio
Anesthesia risks
• Failed intubation 4-6x• Soft tissue mass
• Ventilation difficulties• Breast mass
• Decreased lung volumes
• Failed /difficult regional
Juvin et al, Anesth Analges, 2003; Jordan et al, AJOG, 2004
Long-term Risks
• Increasing maternal obesity• Co-morbidities
• Developmental origins of obesity• Childhood obesity• Metabolic syndrome
Post-Partum Weight Retention
• Gestational weight gain retention• Mean 11.8 lb at 6 months• GWG > IOM
• 15 – 20 lb retention• >40% of women with >20 lb retention
• >50% overweight women are obese by 1 yr postpartum
IOM, 2009; Gould Rothberg, AJOG, 2011
Breastfeeding
• Obese women less likely to breastfeed• BMI 25-30 0.86 (0.84 – 0.88)• BMI >30 0.58 (0.56 –
0.60)
• Missed potential benefits• Maternal
• InfantSebire et al, Intl J Obesity, 2001; Li et al, Am J Pub Health, 2002
Childhood Obesity
• Maternal obesity correlates with neonatal fat mass
• Obesity in offspring of obese mothers• BMI >95th percentile at ages 2-4• OR 2.4 – 2.7
• ↑ Central obesity, lipid abnormalities, hypertension–age 7
Whitaker RC, Pediatrics, 2004; Oken et al, AJOG, 2007;Catalano et al, AJOG 2003, 2004
Summary of Problem
• Scope of the problem is far-reaching• Pregnancy• Life-long• Next generation
Optimizing Perinatal Outcomes
Initial Antepartum Evaluation
• Assessment for co-morbidities• Metabolic syndrome:
• Hypertension
• Glucose intolerance/Diabetes
• Hyperlipidemia
• Sleep apnea
• Early dating US• Oligo-ovulation LMP unreliable
Optimizing Outcomes: Gestational Weight Gain
• Education• Dietary Intake• Exercise
• Set goals and plot weight gain • Only ~250 kcal/d increase needed for
normal weight
Optimizing Outcomes: Gestational Weight Gain
• Total Weight Gain• 11-20 lb• 0.5 lb/wk in 2nd & 3rd trimesters
• Nearly 2/3 of obese women exceed recommended GWG
Gestational Weight Gain
• Excess weight gain associated with• Macrosomia• Operative delivery• NICU
• Weight gain <15 lb associated with lower rates of:• Pre-eclampsia• Cesarean• LGA/SGA
Kiel et al, 2007
Pre-E: Effect of Weight Gain
• Overweight and Obese women
• Weight gain
<15 lb OR 0.5 – 1
> 25 lb OR 1.2 – 1.7
Kiel et al, 2007
Optimizing Outcomes: Early GDM Screening
• Lack of evidence of cost-effectiveness• Target population
• Previous history GDM• Family history of DM• Prior macrosomic infant
• Treatment may lower risks • HgbA1C and risk assessment for other
complicationsCatalano, 2007
Optimizing Outcomes: Reducing pre-eclampsia
• Patients with GDM—Improved glycemic control, lower risk pre-e• ACHOIS—18% vs 12%• MFMU—13.6 % vs 8.6%
Landon et al, 2009; Crowther et al, 2005
Optimizing Outcomes: OSA
• CPAP• Improves symptoms, mood• BP, pre-eclampsia• Birthweight
• Minimize use of narcotic pain relief• Anesthesia consultation• If not confirmed, monitor O2 sats
• Sleep Medicine referralFranklin et al, 2000; Poyares et al,
2007; Guilleminault et al, 2007
Anatomic Assessment
• U/S Visualization• Completion of anatomic assessment declines with increasing
BMI
• 10% decrement per obesity class
Dashe et al, 2009; Thornburg et al, 2009; Weichert and Hartge, 2010; Hendler et al, 2004; Becker and Wegner, 2006
<25 25-29.9 30-34.9 35-39.9 ≥40Basic 72% 68% 57% 41% 30%Targeted 97% 91% 75% 88% 75%
Dashe et al, 2009; Aagaard et al, 2010
• Detection rate decreases with increasing BMI
• Residual anomaly risk increases with BMI
FASTER Trial• Detection aOR 0.70
(0.6-0.9)
Optimizing Outcomes: Anatomic Assessment
• 11-14 week scan• Lack of evidence in obese women
• Combined TA and TV approach• 82% complete anatomy• 3.7% anomaly detection• 84.2% heart defect detection
Ebrashy et al, 2010; Becker and Wegner, 2006
Optimizing Outcomes: Prenatal Diagnosis
• NIPT• Fetal fraction lower
• Adipose cell death• Inflammation
• Redraw rates• Diagnostic Procedures
• BMI ≥40 2-fold increase loss after amnio
Ashoor et al, 2013; Haghiac et al, 2012; Harper et al, 2012
Fetal Fraction in Relation to BMI
Ashoor et al, 2013
Optimizing Outcomes: Growth Surveillance• Macrosomia
• 2-fold increase
• IUGR• Mainly in women with hypertension or pre-eclampsia
• Fundal height• Limited accuracy
• Biometry q4-6 weeks
Ehrenberg et al, 2004; Neilson, 2000; Morse et al, 2009; ACOG CO
#549, 2013
Optimizing Outcomes: Antenatal Testing
• Placental histology • Placental dysfunction OR 5.2
• Vigilance for hypertension, diabetes
• Antenatal surveillance • Even in absence of other indications
Catalano, 2007; Nohr et al, 2005
Optimizing Outcomes: Mode of Delivery• Labor dysfunction
• Increased oxytocin dose• 5.0 units vs 2.6 units
• Longer labor duration• 8.5 vs 6.5 hours
• Impaired myometrial contractility• Leptin inhibitory effect• Not oxytocin receptor mediated
Pevzner et al, 2009; Quenby wt al, 2011; Zhang et al, 2007, 2011; Moynihan et al, 2006; Grotegut et al, 2013
Vaginal vs Cesarean• Swedish birth registry• Neonatal outcomes by mode of delivery• 2-4 fold increase for BMI ≥40 :
• Birth injury• RDS• Sepsis• Hypoglycemia
• Similar risk vaginal vs. elective cesarean
Blomberg, 2013
Optimizing Outcomes: Mode of Delivery• Lack of evidence• Factors to consider
• Increased need for cesarean
• Ability to monitor fetal status
• Time from skin to delivery increased
Gunatilake and Perlow, 2011
VBAC Success
• MFMU Cesarean Registry• >14,000 VBAC attempts
Hibbard et al, 2006
18.5-24.9 25.0-29.9 30-39.9 ≥40 pFailed TOL 15.2 22.3 29.9 39.3 <0.001LOS ≥4d 9.4 13.0 18.9 30.3 <0.001Endometritis 1.6 2.6 3.0 4.6 <0.001Rupture/dehiscence
0.9 1.5 1.4 2.1 0.03
• Reduces risk of puerperal fever• Endomyometritis• Wound infection
• Weight-based dosing modification• Cefazolin
• ≤80 kg 1 gm• 81-160 kg 2 gm• ≥160 kg 3 gm
Perioperative Antibiotics
JCAHO, SCIP recommendations; Smaill et al, 2010;
Cefazolin in obese
• 29 scheduled C/S; 2 gm cefazolin
• Adipose concentration inversely related to BMI• BMI ≥30 20% less than MIC for GNR• BMI ≥40 up to 44% less than MIC
Pevzner et al, 2011
Optimizing Outcomes: Intraoperative management
• Incision type• Fascial Closure• Subcutaneous closure• Appropriate Equipment
• Bed• Instruments• Transfer apparatus
Incision Type and Placement• Pfannenstiel
– Less adipose depth
– Access to LUS– More stable
closure– Moist, anaerobic,
microbe-rich– Cava
compression– Respiratory
impairment intraop
• Vertical• Avoid under pannus• More room• Cut through thicker
part of panniculus• Placement difficult• Increased likelihood
of vertical hysterotomy
• Pulmonary issues post
• Less stable closureWall et al,2003; Alanis et al, 2010; Bell et al, 2011
• 194 women BMI >50• 30% wound complication• Vertical incision OR 2.2 (1.2 – 4.3)
• 239 women BMI > 35• 12% wound complication• Vertical incision OR 12.4 (3.9 – 39.3)
Pfannenstiel vs Vertical
Alanis et al, AJOG, 2010; Wall et al, Obstet Gynecol, 2003
Optimizing Outcomes: Subcutaneous Space Management
• Meta-analysis• Depth >2 cm• Wound disruption RR 0.66 (0.48-0.91)
• Reduction in wound seroma RR 0.42
• No added benefit to drain
Chelmow et al, 2004; Magann et al, 2002; Ramsey et al, 2005
Optimizing Outcomes: Intrapartum management
• Minimize induction of labor, as possible• Anticipate longer length of labor and need for higher
doses of oxytocin• Early epidural placement for analgesia• Decision on best mode of delivery
• Fetal monitoring capability• Prior C/S• EFW
Optimizing Outcomes: Intrapartum management
• Prophylactic cesarean considered for macrsomia• Prepare for pp hemorrhage regardless of mode of
delivery• Choose surgical approach and instruments to
facilitate exposure and technique
ACOG Practice Bulletin 22, 2000
Optimizing Outcomes: Thromboprophylaxis
• Obesity major risk factor• OR 4.4 (3.4 – 5.7) for VTE
• No RCT with benefit of UFH vs LMWH vs pneumatic compression device• At least one form recommended
• High risk patients--heparin plus pneumatic• Vascular disease, thrombophilia, severe pre-e
• Early ambulation
James et al, 2006; Bates et al, 2008; Tooher et al, 2010
• Obesity is associated with an increased risk of a number of maternal obstetric and medical complications
• Good evidence is available to minimize the risk of many complications associated with obesity
• Although data are lacking on how to prevent a number of these complications, careful preparation and anticipation may minimize the risks and improve outcomes in the current and future pregnancies
Summary