In Utero Repair of Myelomeningocele: Atosiban Versus Terbutaline

Assessment of Maternal Blood Gas Changes When Using Atosiban and Terbutaline as Tocolytic Agents, During in Utero Repair of Myelomeningocele

Myelomeningocele is a malformation with high incidence, and it consists in a neural tube defect. Fetal intrauterine surgery is an alternative for correction, and it improves the prognosis of the fetus, but has an increased risk of maternal complications and premature labor, as it can occur due to uterine stimulation. It is therefore essential that tocolysis is performed before, during and after surgery, and the most commonly used tocolytics are terbutaline and atosiban. Terbutaline has no specificity and may have several adverse effects such as maternal acidosis.

The objective of the study was to evaluate maternal blood gas alterations among cases that used atosiban tocolytic agent and cases with terbutaline in in utero repair of myelomeningocele. It consists of a retrospective cohort study. It included 25 patients, who were divided into two groups, depending on which agent they received as main tocolytic agent during the intrauterine fetal myelomeningocele repair: terbutalineor atosiban. The primary outcome was maternal arterial pH at the end of surgery.

Inclusion Criteria:

• Pregnant women over 18 years
• Single fetus pregnancy
• Fetus with myelomeningocele
• Gestational age from 19 to 26
• Fetus with normal karyotype

Exclusion Criteria:

• Multiple pregnancy
• Fetal abnormality not related to myelomeningocele
• Kyphosis greater than or equal to 30 degrees
• Placenta previa
• Maternal disease that increases the risk of pregnancy (insulin-dependent DM, hypertension poorly controlled)
• History of incompetent cervix
• Carrier of HIV, hepatitis B or hepatitis C
• Maternal-fetal isoimmunization
• Uterine Alteration
• Obesity (IMC greater than 30)