The increased risk is minimal, however, with total stillbirth numbers remaining low. The research group reported the findings at the 27thmeeting of the European Society of Human Reproduction.
Morbidity in ART analyzed about 420,000 pregnancies. Approximately 60,000 of the pregnancies were attributed to assisted reproductive technology (ART). The remaining 360,000 pregnancies resulted from natural conception. All pregnancies were singletons – no multiple pregnancies were analyzed. Of the singletons, both natural and assisted, less than half a percent were stillborn. The researchers defined the pregnancy as a stillbirth if the fetus was lost after 22 weeks gestation.
After various factors, such as the age of the mother at the time of conception and fetal gender were taken into consideration, researchers noted an increase in stillbirths of 1.1 fold. This equates to about 8 stillbirths out of 1,000 pregnancies. The difference in stillbirth numbers was found before 37 weeks gestation. When researchers look at rates of stillbirth between 37 weeks and 40 weeks and beyond 40 weeks gestation, there was no increase in the risk of stillbirth. Though there is an increased risk of stillbirth before 37 weeks gestation in pregnancies achieved with ART, the increase is minimal.
This is the first study by Morbidity in ART of this size. The results were pulled from a database with the largest number of medical files pertaining to ART pregnancies in the world. The group is considering future studies involving perinatal morbidity in ART. Perinatal extends the time frame to one year after birth. Researchers also hope to expand future studies to include multiples in addition to singlet births. With the information from this study and future studies in the area of ART morbidity, doctors will be more prepared for the risk factors associated with reproductive technology.
Source: European Society of Human Reproduction and Embryology.