Bariatric Surgery Side Effects May Carry Hidden Pregnancy Risks: Study

Bariatric weight loss surgery may cause pregnancy complications that affect the unborn child, according to the findings of a new study. 

Researchers from the Karolinska Institute in Sweden found women who had bariatric surgery before becoming pregnant may have safer and healthier pregnancies, but it could come at the expense of an increased risk of having babies who suffer complications. The study was published February 26, in the New England Journal of Medicine.

Researchers took data from 600,000 pregnant women between 2006 to 2011 from the Swedish Medical Birth Register focusing on nearly 3,000 women who were obese. They compared the data to 700 women who had undergone bariatric surgery first, before becoming pregnant.

During the study women who had undergone bariatric surgery and became pregnant were matched with up to five other control pregnancies. They were compared by early pregnancy body mass index (BMI) between 35 to 50.

Each woman’s pre-surgery weight was documented and on average women who underwent bariatric surgery became pregnant 15 months after surgery.

They found that the women who had bariatric surgery had a higher risk of having shorter pregnancies and having babies who were smaller than normal. There was also an increased risk of stillbirth and neonatal death.

Prior studies have linked bariatric surgery to other serious complications to patients, including malnutrition, vision problems, and vitamin deficiencies in the months and years following surgery.

Study Found Some Benefits

Despite the potential pregnancy risks following bariatric surgery, the researchers indicate that there were also positive outcomes for the women who had the procedure becoming pregnant.

Women who first had bariatric surgery were 30% less likely to develop gestational diabetes, which makes a woman more likely to develop preeclampsia, low blood sugar, have a miscarriage or have children with birth defects.

These women were also 40% less likely to have excessively large babies, who are more likely to develop lung and blood conditions later on.

There was no increased risk of a woman having preterm birth or any significant difference between the frequency of congenital malformations.

Bariatric Surgery Health Concerns

Another study published late last year raised concerns regarding the side effects of bariatric surgery, despite positive weight loss outcomes. Side effects included reduced long-term survival rates, risks of microvascular and macrovascular events, negative mental health outcomes and increased costs.

About 72,000 American women of child bearing age have bariatric surgery annually. Women who are obese have more problems during pregnancy, including premature babies, overweight or underweight birth weights, and other birth defects.

Patients who undergo bariatric surgery often have positive outcomes leading to weight loss, however results seem to vary widely from person to person, concluded a study published in 2013.

Some patients experienced great weight loss, others found results a year later, while only a small amount were able to hold on to those outcomes three years after the surgery.