ACOG Guidelines at a Glance: Obesity in pregnancy
Obesity in Pregnancy
Obstetrician–gynecologists are the leading experts in the health care of women, and obesity is the most common health care problem in women of reproductive age. Obesity in women is such a common problem that the implications relative to pregnancy often are unrecognized, overlooked, or ignored because of the lack of specific evidence-based treatments options. The management of obesity requires long-term approaches ranging from population-based public health and economic initiatives to individual nutritional, behavioral, or surgical interventions. Therefore, an understanding of the management of obesity during pregnancy is essential, and management should begin before conception and continue through the postpartum period. Although the care of the obese woman during pregnancy requires the involvement of the obstetrician or other obstetric care provider, additional health care professionals, such as nutritionists, can offer specific expertise related to management depending on the comfort level of the obstetric care provider. The purpose of this Practice Bulletin is to offer an integrated approach to the management of obesity in women of reproductive age who are planning a pregnancy.
--Used with permission. Copyright the American College of Obstetricians and Gynecologists
The growing impact of obesity in pregnancy
Dr Copel is Professor, Obstetrics, Gynecology, and Reproductive Sciences and Pediatrics, Yale School of Medicine, New Haven, Connecticut. He is also a member of the Contemporary OB/GYN editorial board.
It is difficult to list all the ways obesity has had an impact on contemporary obstetric practice, ranging from maternal and fetal risks to changes in building design and equipment purchases. In compiling a comprehensive catalogue of these, Practice Bulletin 156 does a tremendous service to everyone involved in the care of the obese gravidas.1
The obesity trend maps available from the CDC (https://www.cdc.gov/obesity/data/prevalence-maps.html) show a remarkable and well-known story documenting the dramatic shifts upward in body mass index (BMI) of the American populace. In 1985, in no state did more than 15% of the population have a BMI ≥ 30. In 2010, in every state at least 20% of the population had a BMI ≥ 30.
The guideline covers a range of issues, starting with the higher risk of spontaneous abortion, running through antepartum and intrapartum complications. Almost everything that can cause trouble in pregnancy becomes more common in obese women, and for many of them, such as stillbirth, there is a “dose-response curve,” with greater risk at higher BMIs. There are 2 early pregnancy issues that are often not sufficiently addressed in current practice, and laid out quite clearly here: the risk of anomalies and the need for early glucose testing.
Risk of fetal anomalies
The risk of many fetal anomalies is significantly increased in obese women, but spina bifida, hydrocephaly, limb reduction anomalies, and congenital heart disease are associated with the greatest increases. The American College of Obstetricians and Gynecologists, Society for Maternal-Fetal Medicine, American Institute of Ultrasound in Medicine, American College of Radiology, and other organizations recently modified their recommendations about who should be referred for a “Level II” ultrasound (CPT 76811) to include those with a BMI >30.2 So, these women should generally not have a “routine” basic (CPT 76805) if a facility able to offer the more detailed scan is available. It is also recognized that the detection rate of anomalies will be lower the heavier the woman.
Early glucose testing
The second issue that is often missed is the recommendation to perform a glucose challenge at the first prenatal visit. Many obese women have unrecognized pregestational diabetes, and waiting until the second trimester to perform a glucose challenge eliminates the opportunity to improve glycemic control in that group at a critical time in fetal development.
As an aside, in the same part of the practice bulletin we are reminded that obese women should be screened by history for obstructive sleep apnea, which carries its own set of pregnancy risks such as preeclampsia, cardiomyopathy, pulmonary embolism, and maternal death.
Much of the PB is composed of important information that is useful to have in the same place, such as weight gain recommendations for obese women. The section on labor floor requirements may be helpful in supporting capital expenses for needed equipment (wider wheelchairs, stretchers and operating room tables that can handle greater weights) or even construction costs (wider doors to accommodate those wheelchairs and stretchers).
We have only begun to appreciate the impact that obesity will have on our professional lives. Obesity means a higher risk of a first cesarean and of additional complex surgeries down the road, including for repeat cesareans and morbidly adherent placentas.
In our primary care role as ob/gyns, it is also worth remembering that even small weight reductions before pregnancy can result in improved outcomes, and we can help women even before they conceive.
Finally, although it is not directly addressed in the PB, caring for obese gravidas carries risk for healthcare providers, from the sonographer who develops an arm injury from scanning heavier women, to the nurse who injures her back moving a patient. We all need to work with our institutions and our professional colleagues to provide the right care to obese women.
1. American College of Obstetricians and Gynecologists. Obesity in pregnancy. Practice Bulletin No. 156. Obstet Gynecol. 2015;126:e112–26.
2. Wax JR, Benacerraf BR, Copel JA, et al. Consensus Report on the 76811 Scan: Modification. J Ultrasound Med. 2015; 34:1915.