Using Zofran during the first trimester has been linked to birth defects, including “musculoskeletal abnormalities” and a doubled increased risk of cleft palate.
What is the problem?
Zofran (ondansetron) is an anti-nausea drug that is used by over 1 million pregnant women per year to prevent severe vomiting associated with morning sickness during the first trimester. Unfortunately, the first trimester is also when many severe birth defects occur — including musculoskeletal defects.
In July 2014, the Toronto Star published an investigative report on 20 women who had a baby with a birth defect after using Zofran. One of those women had a baby with a “musculoskeletal abnormality.” According to the investigators:
“So little is known about how ondansetron affects pregnant women that the drug manufacturer says such use is “not recommended” for these vulnerable patients.”
Zofran and Musculoskeletal Defects
Evidence linking Zofran and musculoskeletal defects continues to grow. The most common defect in this category is cleft palate. In 2012, Birth Defects Research published a study linking Zofran with a 2.4-fold increase risk of cleft palate.
Cleft palate occurs when there is a split or gap in the roof of the mouth. It occurs during the 10th week of pregnancy when the roof of the mouth fails to fuse together. The most serious cases involve both the hard and soft palate, opening a passage between the mouth and nasal cavity. It may also occur with cleft lip and severe dental defects.
Like the name suggests, clubfoot occurs when the foot is bent sharply at the angle, usually inward and downward, so it resembles a club. It is caused by under-development of bones, ligaments, and muscles in the calf and foot.
Children with clubfoot typically undergo physical therapy to gradually stretch the foot into position. They may also need to be fitted with casts to immobilize the foot. In severe cases, complex surgery may be necessary to reconstruct the foot.
Omphalocele and Gastroschisis
Gastroschisis occurs when there is a hole (“hernia”) in the muscles of the abdominal wall, usually at the base of the umbilical cord, which allows the infant’s intestines and organs like the liver, bladder, and stomach to protrude outside the body. A similar condition, omphalocele, occurs when the protruding organs are protected by a membranous sac.
Some of the most common defects involving the arms and legs are limb reduction defects. These abnormalities occur when muscles and bones fail to develop completely, resulting in a shorter, smaller, or missing limb. Children with very severe limb defects may need assistance with personal care and daily activities.