Obesity and Pregnancy
Vanessa H. Gregg, MD
Assistant Professor of OB/Gyn
University of Virginia
Objectives
 Review maternal complications of
obesity in pregnancy
 Review fetal/neonatal complications
of obesity in pregnancy
 Discuss long-term implications
 Review practical issues in the
management of obese pregnant
women
Obesity in America
 Greater than 60% of Americans are
overweight (BMI 25 to <30)
 Of those, half are obese, with a BMI of
30 or greater
 In Virginia, 26% of residents are
obese
Percent of adults who are
obese in Virginia, 2008
http://apps.nccd.cdc.gov/DDT_STRS2/CountyPrevalenceData.aspx?mode=OBS
Defining Obesity
 Overweight = BMI 25-29.9
 Obesity:
 Class 1 = BMI 30-34.9
 Class 2 = BMI 35-39.9
 Class 3 = BMI > 40
Obesity and Pregnancy
 Increasing prevalence of obesity in
pregnancy
 Between 1993 and 2003 the rate of
pre-pregnancy obesity increased
69%
 Approximately 1 in 5 pregnant
women in America is obese.
Kim SY, Dietz PM, England L, Morrow B, Callaghan WM. Trends in pre-pregnancy obesity in nine states, 1993-2003.
Obesity (Silver Spring). 2007 Apr;15(4):986-93.
Maternal Complications
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Higher Rates of Cesarean Section
Gestational Hypertension
Pre-eclampsia
Gestational Diabetes
LGA and Shoulder dystocia
Stillbirth
DVT/PE
Anesthetic complications
Maternal Complications
Complication
BMI 19.8-26
BMI 35-40
Pre-eclampsia
1.4%
3.4% (OR 3.90) 3.5% (OR 4.82)
Cesarean
section
10.9%
21.5% (OR
2.32)
Shoulder
dystocia
0.1%
0.4% (OR 2.82) 0.4% (OR 3.14)
Large for
gestational age
OR 3.11
BMI >40
24.2% (OR
2.69)
OR 3.82
Cedergren, MI. Maternal Morbid Obesity and the Risk of Adverse Pregnancy Outcome. Obstet Gynecol, Vol 103, No 2. Feb 2004.
Risk of Cesarean Section
 Increased risk due to:
 Dysfunctional labor
 Monitoring challenges
 Increased rates of pre-eclampsia,
hypertension and LGA babies all
contribute to likelihood of cesarean
section
Cesarean Section – Clinical
Challenges
 Access to lower uterine segment can
be challenging
 Higher rate of wound complications
after surgery
 Higher risk of anesthetic
complications
Gestational Hypertension
 Pre-existing hypertension is more
common among obese women
 Among those without hypertension
at baseline, increased risk of
developing gestational hypertension
Gestational Hypertension
 Population-based study in the
Netherlands
 Increased rates of gestational
hypertension among obese women
(BMI >35), with odds ratio 4.67
Gaillard R et al. Associations of maternal obesity with blood pressure and the risks of gestational hypertensive disorders.
Journal of Hypertension 2011, 29:937-944
.
Gestational Hypertension: A
UK population-based study
 Among extremely obese women (BMI
>50):
 1 in 5 develop hypertensive disorder in
pregnancy
 1 in ten develop pre-eclampsia
 Among women with less severe
obesity, risk is increased but to a
lesser degree
Knight, M et al. Extreme Obesity in Pregnancy in the UK. Obstet Gynecol, Vol 115, No 5. May 2010
.
Pre-eclampsia
 Risk of pre-eclampsia is increased in
obese pregnant women
 Pre-eclampsia can lead to
compromised fetal perfusion and to
medically-indicated preterm birth.
Pre-Eclampsia
 In same population-based study in
Netherlands, increased risk of preeclampsia was observed for obese
women (BMI >35), with odds ratio of
2.5.
Gaillard R et al. Associations of maternal obesity with blood pressure and the risks of gestational hypertensive disorders.
Journal of Hypertension 2011, 29:937-944.
Gestational Diabetes
 Gestational diabetes is more
common in obese pregnant women
 In addition, there is a higher rate of
pre-existing diabetes in obese
pregnant women
Gestational Diabetes: A UK
population-based study
 Among extremely obese women,
11% developed gestational diabetes
 Of those, 70% required insulin
 Risk of developing diabetes was seven
times higher than in non-obese controls
 Among women with less severe
obesity, risk is increased but to a
lesser degree
Knight, M et al. Extreme Obesity in Pregnancy in the UK. Obstet Gynecol, Vol 115, No 5. May 2010
Large for Gestational Age and
Shoulder Dystocia
 Maternal obesity predisposes to
increased size of babies at birth.
 Increased fetal adipose tissue,
especially in the fetal abdomen,
increases risk of shoulder dystocia
 Shoulder dystocia carries additional
morbidity to mother and baby.
Risk of Stillbirth
 There is an increased risk of stillbirth
associated with obesity
 Risk of stillbirth increases with
severity of obesity
Cohort Study of
Rates of Stillbirth
 One study of birth cohort in Missouri
1978-1997 examined >1.5 million
births:
 Obese mothers were 40% more
likely to experience stillbirth
.
Salihu, HM et al. Extreme Obesity and Risk of Stillbirth Among Black and White Gravidas. Obstet Gynecol 2007; 110:552-7
Cohort Study of
Rates of Stillbirth
 There was significant racial disparity,
with higher rates of stillbirth among
black women than white women
 Disparity widened with increasing
BMI, with disproportionately highest
stillbirth among extremely obese
black women (BMI > 40).
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Salihu, HM et al. Extreme Obesity and Risk of Stillbirth Among Black and White Gravidas. Obstet Gynecol 2007; 110:552-7
DVT/PE
 Immobilization and pregnancy are
both risk factors for DVT/PE
 Obese pregnant women often have
decreased mobility, particularly with
extreme obesity
 Cesarean delivery further increases
the risk
Anesthetic Complications
Inability to establish regional block
Insufficient duration of regional block
Longer time to establish anesthesia
Refractory hypotension from
anesthetic agents
 Increased postdural puncture
headache
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Vricella LK et al. Anesthesia Complications During Scheduled Cesarean Delivery for Morbidly Obese Women.
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Am J Obstet Gynecol 2010;203:276.e1-e5
Fetal and Neonatal
Complications
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Stillbirth
Fetal Distress in Labor
Meconium Aspiration
Neonatal Death
Fetal and Neonatal
Complications
Complication
BMI 19.8-26
BMI 35.1-40
BMI > 40
Stillbirth
0.3%
0.6% (OR 1.99) 0.8% (OR 2.79)
Fetal distress
2.0%
3.5% (OR 2.13) 3.9% (OR 2.52)
Meconium
aspiration
0.1%
0.3% (OR 2.87) 0.3% (OR 2.85)
Neonatal death
0.1%
0.3% (OR 2.09) 0.4% (OR 3.41)
Cedergren, MI. Maternal Morbid Obesity and the Risk of Adverse Pregnancy Outcome. Obstet Gynecol, Vol 103, No 2. Feb 2004.
Fetal and Neonatal
Complications
 As maternal BMI has risen, there has
been a significant increase in the
number of babies born with high
birth weight.
 Larger babies have more adipose
tissue.
Surkan PJ, Hsieh CC, Johansson AL, Dickman PW, Cnattingius S. Reasons for increasing trends in large for gestational age births.
Obstet Gynecol 2004; 104: 720-6.
What happens later in life
for children born
to obese mothers?
 Children born to obese mothers are
twice as likely to be obese and
develop type 2 diabetes in adult life.
 Higher maternal gestational weight
gain has been associated with high
blood pressure in offspring.
http://www.cdc.gov/reproductivehealth/MaternalInfantHealth/PregComplications.html
Contemplating the mechanism
 One study showed an association
between maternal BMI and the
hepatic lipid content in the infants.
 The increased lipid content in the
liver may initiate programming of the
metabolic syndrome in utero.
Modi, N et al. The Influence of Maternal Body Mass Index on Infant Adiposity and Hepatic Lipid Content. Pediatric Research; Vol. 70, No. 3, 2011.
More Evidence: Early Menarche
in Female Offspring
 An NICHD study looked at age of
menarche and found an association
between maternal obesity and earlier
menarche in female offspring.
 There was also a correlation between
maternal BMI and daughters’ BMI at
age seven.
Kleim SA, Branum, AM, Klebanoff MA, Zemel BS. Maternal Body Mass Index and Daughters’ Age at Menarche.
Epidemiology. Vol 20, Number 5, Sept 2009.
Effects of Early Menarche
 Early puberty is associated with
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Glucose intolerance
Hypertension
Depression
Breast Cancer
Kleim SA, Branum, AM, Klebanoff MA, Zemel BS. Maternal Body Mass Index and Daughters’ Age at Menarche.
Epidemiology. Vol 20, Number 5, Sept 2009.
Optimal intrauterine growth
affects long-term health
 Inadequate and excessive fetal
growth in utero both have the
potential to predispose to the
metabolic syndrome in adulthood.
 Goal is “optimal” fetal growth,
though this can be hard to define
and achieve.
Optimal intrauterine growth
affects long-term health
Maternal Obesity
Fetal
Programming
Offspring Obesity
and Metabolic
Syndrome
Practical Considerations
 Increased utilization of healthcare
resources
 Difficult to use some of our routine
prenatal surveillance tools
 Increased hospital challenges
Utilization of Resources
 Obesity in pregnancy is associated
with:
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Longer hospital stays
Greater use of health care services
More obstetric ultrasounds
More prescribed medications in
pregnancy
http://www.cdc.gov/media/pressrel/2008/r080402.htm
Clinic Challenges
 Identifying fetal heart tones
 Assessing fetal growth
 Fundal height difficult to obtain
 Assessing for hypertension
 Blood pressure cuffs may be of
inadequate size
Hospital Challenges
 Monitoring
 Anesthesia
 Identifying epidural space
 Airway protection
 OR table limitations, surgeries
technically more challenging
 Increased risk of DVT due to
immobilization
Strategies for Improvement
 Will be discussed further in next talk
 Institute of Medicine (IOM) provides
weight gain guidelines by age.
 Guidelines are not stratified by
obesity classes.
 May be that less weight gain is
better, particularly for women with
BMI above 40.
Summary
 Increased rates of obesity in
pregnancy have led to increasing
complications for mother and baby
 There are long-term consequences of
obesity on future health outcomes
 Obesity in pregnancy contributes to
increased health care costs
Optimizing maternal prepregnancy weight and
controlling gestational weight
gain can have far-reaching
consequences on future health
of the population and on
health care costs.