For the study, the researchers analyzed over 10 years’ worth of health records from two hospitals, Medway Maritime Hospital in Gillingham and Kings College Hospital in London, which included almost 90,000 pregnancies.
Of this group, 57,131 pregnancies from 2006 to 2017 had health records from 11 to 13 weeks. And within this subset, 1,138 cases had at-term preeclampsia.
From 2016 to 2018, there were 29,035 pregnancies with health records at 35 to 36 weeks. And 619 of these pregnancies had at-term preeclampsia.
Through this analysis, the team worked to evaluate the risk of preeclampsia as well as the prospective benefits of timed births among both groups of women.
This was made possible by combining the standard preeclampsia clinical criteria with a risk prediction model– or a computer program able to predict preeclampsia risk using numerous individual risk factors, including blood pressure, blood tests, maternal history, and ultrasounds.
Most of the women were in their early 30s, had a body mass index (BMI) at the upper end of “normal,” and self-identified as white. Approximately 10% of the participants also reported they smoked; meanwhile, less than 3% had a history of Type 2 diabetes, high blood pressure, or an autoimmune disease.
Additionally, just 3.9% of the women reported having a family history of preeclampsia.
After comparing patients screened during their first trimester with those screened during their third trimester, the team found that at-term preeclampsia frequency rates were similar.
About two-thirds of the participants experienced spontaneous labor onset; meanwhile, approximately one-fourth of the participants had Cesarean deliveries.
On average, the women also delivered their babies at 40 weeks.
According to the researchers, though, their analysis– which used risk modeling instead of standard clinical screening– revealed that timed births might be a more effective intervention. In fact, it has the potential to reduce the risk of at-term preeclampsia by more than 50%.