Women who become pregnant via in vitro fertilization (IVF) and face serious complications during their pregnancy are at twice the risk of delivering prematurely (before 37 weeks) compared to those who have just one of these issues, a researcher from Rutgers Health has found.
Published in JAMA Network Open, the study reviewed nearly 79 million hospital deliveries across the United States over a span of 20 years. This research is the first to look into how assisted reproductive technologies, like IVF, and placental abruption together influence the rates of preterm births. In medical discussions, assisted reproductive technology is often referred to as ART.
“It’s essential for patients going through IVF to understand all possible outcomes, especially given the stress they already face,” stated Jennifer Zhang, the study’s lead author and a resident in obstetrics and gynecology at Rutgers Robert Wood Johnson Medical School.
The research took advantage of the National Inpatient Sample, one of the nation’s largest inpatient databases, which includes hospital information from 48 states. Analyzing data from 2000 to 2019, the team identified over 391,000 pregnancies resulting from assisted reproduction and more than 850,000 instances of placental abruption, a known risk where the placenta detaches from the uterus prior to delivery.
Their findings indicated that women who conceived with ART had a 42 percent increased risk of experiencing placental abruption compared to those who conceived naturally. Additionally, these women were found to have a 46 percent higher probability of premature birth than those conceived without ART.
When both risk factors occurred together, a compounded effect was evident.
The study also revealed racial and ethnic disparities. White women using ART experienced a 42 percent increased risk of placental abruption, aligning closely with the overall average. Hispanic women faced an even greater risk at 66 percent. Conversely, Black women who utilized ART showed no increased risk for abruption compared to their naturally conceiving counterparts.
These results could substantially impact clinical practices, although Zhang warned against making immediate changes based on this single study.
“Prospective research is essential to validate these findings,” remarked Cande Ananth, the senior author and chief of the Division of Epidemiology and Biostatistics in the Department of Obstetrics, Gynecology, and Reproductive Sciences at Rutgers Robert Wood Johnson Medical School. “However, it could influence how practitioners respond in certain cases, particularly since studying this relationship directly through prospective methods would be challenging.”
For example, doctors may become more proactive if an IVF patient exhibits indications of placental abruption. It might also be valuable to explore whether the kind of infertility treatment and its duration impact both placental abruption and the likelihood of preterm delivery.
This research coincides with an increase in the use of ART. The Centers for Disease Control and Prevention report that around 2 percent of infants in the U.S. are conceived using these techniques, a rise from less than 0.5 percent in 2000. With the growing application of ART, many are becoming more concerned about its potential complications. “ART pregnancies already come with heightened risks for conditions such as preeclampsia and low birth weight,” Zhang noted, adding that this study introduces new insights into another complication.
Nonetheless, the research has its limitations. As a retrospective analysis of hospital records, it couldn’t capture all possible confounding variables or differentiate between various ART methods. The team also pointed out that their dataset likely underrepresents the actual number of ART pregnancies due to hospital coding practices, which may not consistently document this information accurately.
Despite these limitations, the findings highlight the importance of vigilant monitoring of ART pregnancies, especially when complications arise, emphasizing the intricate relationship between fertility treatments and pregnancy outcomes.
Looking to the future, researchers are now focusing on other possible complications associated with ART pregnancies.
“We’re investigating the relationship between ART and stillbirth,” Zhang stated.
