Gastroschisis is a congenital defect where a baby’s intestines, and sometimes other organs, protrude outside the abdominal wall. This condition develops early in pregnancy, and ultrasound plays a central role in its detection and monitoring. Understanding how ultrasound helps diagnose and track gastroschisis prepares families and medical teams for the baby’s care.
Understanding Gastroschisis
Gastroschisis is an abdominal wall defect characterized by a full-thickness opening, typically located to the right of the umbilical cord. Through this opening, bowel loops and occasionally other abdominal organs, such as the stomach or liver, extend outside the fetal abdomen into the amniotic fluid. A distinguishing feature of gastroschisis is the absence of a protective membrane or sac covering the exposed organs, unlike other similar conditions.
The cause of gastroschisis is often unknown and not typically linked to other genetic conditions. Its prevalence has increased globally, with reported rates ranging from approximately 1 in 3,600 to 5 in 10,000 live births. Exposure of the fetal bowel to amniotic fluid can lead to irritation, causing the intestines to become thickened, matted, or dilated.
Detecting Gastroschisis with Ultrasound
Gastroschisis is often identified during prenatal ultrasound examinations, typically around 18 to 20 weeks of gestation, though detection can occur as early as 11 to 14 weeks. During an ultrasound, medical professionals look for specific visual cues, such as free-floating loops of bowel outside the fetal abdomen.
Ultrasound is also useful in distinguishing gastroschisis from other abdominal wall defects like omphalocele. In omphalocele, the herniated organs are covered by a membrane, and the umbilical cord inserts directly into the defect, which is not the case with gastroschisis. An elevated maternal serum alpha-fetoprotein (AFP) level can also indicate a higher risk of gastroschisis, prompting a more detailed ultrasound investigation.
Ongoing Ultrasound Monitoring
After an initial diagnosis of gastroschisis, regular ultrasound scans become a consistent part of prenatal care. These follow-up examinations help the medical team monitor the condition and various aspects of fetal health. One focus is assessing fetal growth, as babies with gastroschisis may experience intrauterine growth restriction.
Ultrasounds also observe the appearance of the exposed bowel, noting any thickening or dilation, which can indicate irritation from amniotic fluid exposure. Monitoring amniotic fluid levels is important, as oligohydramnios (low fluid) or polyhydramnios (excess fluid) can occur and may signal potential complications like bowel atresia. These ongoing assessments allow healthcare providers to make informed decisions about the remainder of the pregnancy and delivery planning.
Preparing for Delivery and Beyond
The diagnosis of gastroschisis through ultrasound initiates a comprehensive care plan involving a multidisciplinary team of specialists, including maternal-fetal medicine, neonatology, and pediatric surgery. Delivery is typically planned at a specialized hospital equipped with a neonatal intensive care unit and pediatric surgical services, ensuring immediate access to expert care for the newborn.
While the timing of delivery can vary, current research suggests that planned induction or delivery at 36-37 weeks gestation does not necessarily improve outcomes compared to spontaneous labor or delivery at 38 weeks or later. Vaginal delivery is generally recommended unless there are specific obstetric reasons for a Cesarean section. After birth, immediate management typically involves protecting the exposed bowel, often by placing it into a specialized bag, followed by surgical repair to return the intestines to the abdominal cavity.