Obesity and Pregnancy

Vanessa H. Gregg, MDAssistant 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

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 BMI >40

Pre-eclampsia 1.4% 3.4% (OR 3.90) 3.5% (OR 4.82)

Cesarean section

10.9% 21.5% (OR 2.32)

24.2% (OR 2.69)

Shoulder dystocia

0.1% 0.4% (OR 2.82) 0.4% (OR 3.14)

Large for gestational age

OR 3.11 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 pre-eclampsia 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).

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

Vricella LK et al. Anesthesia Complications During Scheduled Cesarean Delivery for Morbidly Obese Women.

Am J Obstet Gynecol 2010;203:276.e1-e5.

Fetal and Neonatal Complications

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 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: 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 pre-pregnancy weight and controlling gestational weight gain can have far-reaching consequences on future health of the population and on health care costs.