Obesity and Pregnancy

Obesity in pregnancy can affect the health of the baby and mother. Obesity is a global health problem that affects more than a third of the population and is caused by a combination of genetic and environmental factors.

In fact, decreased physical activity and a sedentary lifestyle are strongly associated with an increase in the number of people with obesity. Obesity threatens almost all aspects of health, from reproductive function and respiration to memory and mood. It also increases the risk of several dangerous diseases, including diabetes, heart disease, and some cancers. Maternal weight before pregnancy and during pregnancy can affect the health of the mother and baby.

Starting a pregnancy with a normal body mass index (BMI) and weight gain, according to the recommended amount during pregnancy, is an important way to ensure the health of the mother and fetus.

What is obesity?

Being overweight is defined as having a body mass index (BMI) between 25 and 29.9. Obesity is defined as having a BMI of 30 or more. In the general classification of obesity, three levels indicate an increase in health risks associated with an increase in BMI:

• Obesity category I: BMI of 30 to 34.9
• Obesity category II: BMI of 35 to 39.9
• Obesity category III: BMI of 40 or greater

Complications of overweight or obesity in pregnancy

Before pregnancy, if a woman is overweight or obese, she is less likely to get pregnant than women at a healthy weight. Obesity can also affect a special type of fertility treatment called in vitro fertilization (IVF). IVF is when an egg and sperm combine in the laboratory to form an embryo and are implanted in the uterus. The higher the BMI, the less likely become pregnant with IVF.

It may also be difficult to perform tests such as ultrasound. Excess body fat can make it difficult to see a baby with an ultrasound. Checking a baby’s heart rate during labor may also be more difficult. One of the complications of pregnancy is round ligament pain. Probably, the more the mother is overweight during pregnancy, the more pain she experiences. If the mother is overweight or obese during pregnancy, the following complications are more likely to occur.

High blood pressure

High blood pressure is when the force that blood exerts on the walls of blood vessels is too high. Preeclampsia is a complication that can occur after the twentieth week of pregnancy or just after pregnancy. It is when a pregnant woman has high blood pressure and has symptoms that indicate that some of her organs, such as her kidneys and liver, may not be working correctly. Clotting problems are when a blood clot partially or completely blocks blood flow in a blood vessel.

Gestational diabetes

It is a type of diabetes that some women get during pregnancy. Gestational diabetes puts the mother at risk for postpartum diabetes. The mother may also need to stay in the hospital more often than women who are healthier weight.

If the mother has gestational diabetes, the baby may have breathing problems, low glucose levels, and jaundice.

• Complications of cesarean section: Cesarean birth is a surgery in which the baby is born through an incision made by a doctor in the abdomen and uterus. If the mother is obese, the complications of cesarean section, such as infection or excessive blood loss, are more likely.

• Miscarriage: Obesity, defined as a body mass index above 30, is associated with an increased risk of pregnancy complications, including miscarriage and recurrent miscarriage. Weight loss can reduce the risk of miscarriage in obese women, even among women with a history of miscarriage.

• Sleep apnea: There is a linear correlation between obesity and apnea. In obese people, fat deposits in the upper respiratory tract narrow the airway. Decreased muscle activity in this area leads to hypoxic and apnea episodes and eventually to sleep apnea.

Obese women are more likely to have other side effects, including:

• Infections during pregnancy, like urinary tract infections
• A dangerous blood clot problem called venous thromboembolism
• Needing to go to the hospital earlier in labor, having longer labor, and needing to have your labor induced

Obesity  in pregnancy and its effect on the baby

If the pregnant mother is overweight or obese during pregnancy, the baby is more likely to get these conditions:

• Premature birth: Delivery occurs before 37 weeks. This is too early and can cause serious health problems for the baby.

• Birth defects: These include neural tube defects (also called NTDs), and heart defects. Neural Tube Defects are birth defects of the brain and spine. A birth defect is a health condition that a baby develops at birth. Birth defects change the shape or function of one or more parts of the body. They can cause problems with overall health, how the body grows or how the body functions.

• Macrosomia: A baby weighs more than 8 pounds, 13 ounces at birth. When a baby is so large, it can cause complications during childbirth. Also, the possibility of cesarean delivery increases.

How much weight should be gained during pregnancy?

The amount of weight a pregnant mother should gain during pregnancy depends on her pre-pregnancy weight and BMI.

Single pregnancy

If the mother has a BMI of 30 or higher and she has to carry one baby, the recommended weight gain is 11 to 20 pounds (about 5 to 9 kg).

Multiple pregnancies

If the mother has a BMI of 30 or higher and is carrying twins or multiples, the recommended weight gain is between 25 and 42 pounds (about 11 to 19 kg).

For women with a BMI of 40 or higher, gaining less than the recommended amount or losing weight during pregnancy may reduce the risk of a cesarean or overweight baby. It may also increase the risk of giving birth to a baby who weighs less than expected for gestational age.

Specialized care during pregnancy

If the BMI is 30 or higher, the obstetrician will closely monitor the pregnancy.

Early testing for gestational diabetes

For women at moderate risk for gestational diabetes, a screening test called a glucose challenge test is often done between 24 and 28 weeks of pregnancy. If she has a BMI of 30 or higher, the doctor may recommend a screening test at the first visit. In the case of results are normal, the screening test will probably be repeated between 24 and 28 weeks of pregnancy. If the results are abnormal, more tests are needed. 

Changes fetal ultrasound

Standard fetal ultrasound is usually done between 18 and 20 weeks of pregnancy to assess the baby’s anatomy. But ultrasound waves do not easily penetrate the adipose tissue of the abdomen. This can interfere with the effectiveness of fetal ultrasound. The doctor will do the best way to get an accurate ultrasound.

Screening for obstructive sleep apnea

This is a potentially serious sleep disorder that causes to stop breathing repeatedly and start again. Women with obstructive sleep apnea during pregnancy are at risk for preeclampsia and other complications. It will probably be screened at the first visit. If obstructive sleep apnea is suspected, the doctor refer the pregnant mother to a sleep specialist for evaluation and treatment.

Steps to have a healthy pregnancy

Steps include:

• Seek regular prenatal care: Regular checkups are essential to ensure the condition of the mother and fetus. Prenatal visits can help the health care provider monitor the health of the mother and baby. The mother should tell her healthcare provider about any illness she has, such as diabetes, high blood pressure, or sleep apnea, and what she can do to manage them.
• Schedule a preconception appointment: If the mother has a BMI of 30 or higher and plans to become pregnant, she should talk to her healthcare provider. She usually introduces the mother to a nutritionist who can help the mother reach a healthy weight before pregnancy.

• Eat a healthy diet: To maintain a healthy diet and prevent overweight, the mother should work with a health care provider or nutritionist. The mother needs more folic acid, protein, calcium, iron, and other essential nutrients during pregnancy.
• Be physically active: Overweight pregnant women should talk to their doctor about safe ways to stay physically active during pregnancy, such as walking, swimming, or doing aerobics.

Where does pregnancy weight gain go?

The baby weighs about 7 or 8 pounds (about 3 to 3.6 kg); other added weights include:

• Larger breasts: 1 to 3 pounds
• Larger uterus: 2 pounds
• Placenta: 1 1/2 pounds
• Amniotic fluid: 2 pounds
• Increased blood volume: 3 to 4 pounds
• Increased fluid volume: 2 to 3 pounds
• Fat stores: 6 to 8 pounds

The bottom line

Considering the increase in complications related to obesity in pregnancy, it is essential that doctors and patients are aware of its risks. One of the preparations before pregnancy is weight preparation, which means that a woman should enter the stage of pregnancy with proper weight and have a balanced and appropriate weight gain during nine months of pregnancy.

Obese women have lower fertility, mostly due to ovarian dysfunction, and are more likely to have miscarriages even when they become pregnant with infertility treatment. The recommended amount of weight gain for a woman during pregnancy depends on their pre-pregnancy weight.

Arjang Naim MD examines the client’s condition before attempting to conceive and makes the necessary recommendations. He also checks the mother’s weight regularly during pregnancy.

Additional questions