Why Discouraging Maternal Obesity is Not Fat-Shaming

By Kristine Hartvigsen on June 30th, 2017

Patient education has come pretty far in recent years. Most U.S. women today understand that being pregnant does not mean “eating for two.” In fact, invoking one’s maternal license to belly up to the smorgasbord can be detrimental to the health of both mother and baby.

According to the American College of Obstetricians and Gynecologists (ACOG), obesity is the most common healthcare problem among women in their reproductive years. An estimated 60% are overweight, and 35% are obese (generally defined at having a Body Mass Index [BMI] of 30 or greater).

ACOG recommends that women try to address obesity before they get pregnant, because even a modest weight loss of 10-20 pounds can have a profound impact on their later risk for pregnancy complications such as preeclampsia, gestational diabetes, fetal macrosomia, venous thromboembolism (VTE), miscarriage, premature birth, birth defects, cognitive deficits, and stillbirth. Their babies similarly carry a higher risk for such things as autism spectrum disorder (ASD), adult obesity, diabetes, adult heart disease, and neurodevelopmental delays.

A pervasive concern, especially for women who desire to deliver vaginally, is the risk for macrosomia (a baby that is considerably larger than average for a newborn). Large babies can make vaginal delivery difficult and increase the likelihood of cesarean delivery. A large baby is more likely to experience shoulder dystocia, in which the baby’s shoulder gets wedged at the top of the birth canal. Shoulder dystocia can cause a number of injuries, including nerve damage from a brachial plexus injury, which can cause upper extremity paralysis or loss of function.

Birthing a newborn with macrosomia also elevates a woman’s risk of incurring damage to the birth canal and perineum as well as experiencing dangerous bleeding or uterine rupture.

The most recent research on maternal obesity published earlier this year came from an examination of 1.2 million birth outcomes in Sweden. Researchers found that the risk for infant heart defects, nervous system malformations, and limb deformities increased commensurate with the mother’s degree of obesity at the beginning of her pregnancy. They found that the most severely obese women were 37% more likely to have babies with birth defects than normal-weight mothers.

Older research already has demonstrated a link between maternal obesity in the first trimester and later obesity in children. In fact, scientists hypothesized that increasing rates of maternal obesity can trigger an unwanted self-perpetuating phenomenon based on “in-utero fetal programming by nutritional stimuli.” In other words, the quality and quantity of nutrition passed to the baby through the placenta may permanently alter the baby’s metabolism. All the more reason for expectant women to exercise, eat healthy, high-quality foods, and be wary of portion size.

ACOG estimates that women in their second and third trimesters need an average of just 300 extra calories a day, which is about the same as a glass of skim milk and half a sandwich. How much weight a woman should gain during her pregnancy is best determined with her physician. However, some guidelines recommend that obese women carrying one baby should gain 11-20 pounds. Obese women carrying multiple babies should gain about 25-42 pounds.

Excessive body fat can make it more difficult for clinicians to properly view the baby’s anatomy via ultrasound and to hear the baby’s heart rate during labor. Another practical reason to monitor and manage weight during pregnancy is to avoid infections, the likelihood of a longer labor, and problems with breastfeeding. Obese women also are more likely to need more prenatal visits than usual to closely monitor for obesity-related issues.

OB/GYNs highly recommend that obese women schedule a preconception checkup before they are pregnant. This can help them get out ahead of weight issues and possibly even lose weight before becoming pregnant. At this time, clinicians can provide guidance for healthy eating and lifestyle during pregnancy.

“Pregnancy should not be looked at as a state of confinement,” said ACOG’s Dr. Raul Artal. “In fact, it is an ideal time for lifestyle modification. That is because, more than any other time in her life, a pregnant woman has the most available access to medical care and supervision.”

This blog provides general information and discussion about healthcare-related subjects. The content and linked materials provided are not intended and should not be construed as medical advice. If the reader is an expectant mother with a medical concern, she should consult with an appropriately licensed physician or healthcare provider.


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