Understanding Obesity During Pregnancy

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Pregnancy and weight are something that is often talked about, though most of the discussions tend to center around gaining weight while you are pregnant. Another issue is what happens during a pregnancy when someone begins pregnancy with obesity

How Obesity Is Defined in Pregnancy

More and more people begin pregnancy with excess weight. Overweight is defined as having a body mass index (BMI) between 25 and 29.9, while obesity is defined as a BMI above 30. These are the same definitions that are used prior to pregnancy. The BMI is typically calculated on the pre-pregnancy weight and not the weight gain in pregnancy.

How Obesity Affects Pregnancy

The very first issue that someone with excess weight or obesity may encounter when trying to get pregnant is trouble conceiving. Between 38-88% of people with polycystic ovarian syndrome (PCOS) have excess weight or obesity. PCOS is one of the most common causes of infertility. In addition, obesity is associated with reproductive disorders like anovulation (lack of ovulation), menstrual disorders, and difficulty with assisted reproduction.

Once pregnant, there are other potential complications, including increased risk of:

Each of these issues has their own risks associated with them. It can mean that you need to have an increased number of prenatal care visits, that you require medications, or closer monitoring. This is one reason why prenatal care is so important and why it is important that it be tailored to you.

Pregnancy Weight Gain 

One thing that is clear: Even if you start pregnancy with excess weight, it is still important to gain weight in pregnancy. A person with excess weight or obesity will need to gain less weight for a healthy pregnancy, but weight gain is still encouraged.

For people who are overweight, a weight gain of 15 to 25 pounds is recommended. For those pregnant with twins, this weight gain goal increases to 31 to 50 pounds total.

If you have obesity at the start of pregnancy, the CDC recommends a weight gain total between 11 and 20 pounds. If you are expecting twins, that number rises to 25 to 42 pounds total.

Losing Weight While Pregnant

It is not recommended that anyone attempt to lose weight in pregnancy. This is true no matter what your starting weight is. Dieting in pregnancy deprives your baby of needed calories. It can also result in a baby being born too small. This is not to say that you should eat whatever you want. A diet that is well rounded and full of hearty foods is much better for your pregnancy and baby than a diet that is high-calorie and low-quality.

Labor in People With Obesity

There are many beliefs that have been held about labor in people with excess weight or obesity. Research has helped clarify these thoughts and to put them into a modern medical context. Pregnant people who are obese may have an increased risk for:

People with excess weight or obesity may have a longer first stage of labor, the part where the cervix is dilating. A practitioner may need to provide extra time in this phase of labor as both the parent and fetus are doing well.

Epidural anesthesia is possible for women in a higher weight category, though it may be technically more challenging for the anesthesiologist. If you fall into this category, consider a pre-labor consultation with the anesthesia department at your hospital. This way there may be fewer surprises during labor.

In addition to a prolonged first stage of labor, obesity has been found to be an independent risk factor for prolonged second stage of labor, as well. It is also an important point to note that an increased BMI seems to have a protective effect against having a third or fourth-degree laceration on the perineum.

Induction of Labor and Cesarean Birth

Cesarean section has its own set of issues people with excess weight and obesity. It is important to note that a planned cesarean section for weight alone does not improve the neonatal or maternal morbidity. The risk for needing a cesarean is not as straightforward as one might assume.

Reasons for cesarean in those with obesity include:

  • Arrested labor
  • Fetal distress 
  • Macrosomia
  • Provider bias toward cesarean

Obesity is a risk factor for dysfunctional labor. People with obesity are less likely to start labor spontaneously and less likely to have a vaginal birth when they begin labor on their own. For these reasons, induction and augmentation are more common, which may be why there are more c-sections in people with obesity.

What we do know is that people who have excess weight or obesity do have a higher rate of complications that would make an induction of labor the appropriate intervention. What comes next is balancing the risks of prolonging the pregnancy and the risks of induction and potential cesarean birth.

A cesarean birth is technically more challenging from the standpoint of the anesthesia team and the surgeon. This is another time when having adequately sized equipment can be very helpful for both the surgeon and the patient.

Preconception Planning for the Future

Ideally, obesity and weight-related issues are addressed prior to pregnancy. What experts do agree on is that when possible, you should lose weight before trying to conceive. Even just 5-7% of weight loss can reduce obesity-related pregnancy risks.

If you are having trouble with losing weight or chose not to wait to conceive, then be sure that you are working to be as healthy as possible. Good preconceptional health screening can identify any potential health issues and you can address those prior to getting pregnant. This will help your future pregnancy be healthier.

High-Risk Label

Many people find themselves being placed in a high-risk category because of their obesity. Even in the absence of chronic problems, you may be faced with interventions or testing that you may not want.

While excess weight and obesity may increase the risk for some complications, that does not mean you will absolutely have complications in pregnancy. There is simply a greater chance of it happening.

Even with a high-risk label, you may still be able to have the kind of pregnancy and birth you desire. This largely depends on the practitioner that you chose and their guiding philosophy. As a pregnant person, you do have rights and can exercise them. This can include finding a new practitioner if appropriate.

What to Do If You Feel Like You Are Treated Poorly Because of Your Weight

Weight stigma may be common in maternity care settings. If you experience poor treatment, speak up. Your doctor or midwife may not realize that you are feeling bad about your care. This allows you a chance to clear the air. If you aren’t comfortable doing this in person, consider writing a letter to your provider.

As a pregnant person, you have a right to be treated respectfully and with the care that is appropriate for your pregnancy and/or medical conditions. This includes ensuring that you have appropriate medical equipment—for example, a well-fitting blood pressure cuff (instrumental in ensuring that your blood pressure is being measured adequately), scales that weigh you accurately, and furniture that fits you, including labor beds and exam tables.

If your concerns are not addressed to your satisfaction after you communicate them to your providers, consider seeking care from another group of physicians.

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