What determines risk factors in pregnancy? New research

If you’ve seen a Babymoon Inn staff member lately, you’ve probably noticed a shirt that reads, “Evidence-based care with a hug. #birthcenters.” As an accredited birth center, we have a long history of providing holistic and personalized care, but also care that is driven by evidence and what research has shown to lead to the best outcomes for parents and babies.

What that research has demonstrated again and again is that for healthy, low-risk people, accredited birth centers tended by midwives are the safest place to have a baby.

But what makes someone low-risk? New research has identified factors to help determine a person’s risk status and help guide them to the choice of birth location that is appropriate for them.

Jeanette McCullough, IBCLC and co-founder of BirthSwell, interviewed one of the researchers, Melissa Cheyney, PhD, CPM , about the results of the study and its implication on maternity care and policy-making.

Cheyney acknowledged that “there is actually very little agreement on what constitutes ‘low-risk” and that the majority of research on risk factors has been limited to a hospital setting, whereas this new study includes nearly 50,000 people seeking planned birth center or home birth.

The study looked at eight risk factors:

  • primiparity (having your first baby)
  • history of a prior cesarean (with or without a history of also having a vaginal birth)
  • multiple pregnancy
  • breech presentation
  • gestational diabetes
  • preeclampsia
  • post-term pregnancy (greater than 42 weeks
  • advanced maternal age
  • elevated body mass index.

The study compared the risk factors with the following outcomes:

  • likelihood of transfer
  • cesarean section
  • any genital tract trauma
  • any postpartum hospitalization for a maternal indication in the first 6 weeks
  • low 5-minute Apgar score (<7)
  • very low 5-minute Apgar (<4)
  • any neonatal hospitalization in the first 6 weeks
  • any NICU admission in the first 6 weeks
  • combined fetal and neonatal death

The outcomes of Cheyney’s research showed that:

“Older than average mothers (35 years and older), women with an elevated BMI (30 and over) and women who labored after a cesarean who had also had a vaginal birth all had very little additional risk relative to our comparison group… Women who are older, heavier, or who have had a previous C-section and a vaginal birth who have no other complications actually do quite well in the community setting, and we are hopeful that state regulations will be modified to reflect these findings where needed.”

The research also gives insight into the risks of VBAC (vaginal birth after Cesarean) in an out-of-hospital setting.

“Women who labored after a cesarean who had also had at least one vaginal birth had excellent outcomes in the community setting. In fact, their risk was lower than what we found for women having their first baby.  However, we also found that clients laboring after a cesarean who have not had a vaginal birth were at higher risk than anticipated. Their outcomes grouped among the highest risk of the subgroups we analyzed, which included breech and preeclampsia. Women laboring after a cesarean without a previous vaginal birth had a risk of fetal or neonatal death that was ten times higher than the low risk comparison group of healthy multiparous women with no risk factors. Their rate of fetal and neonatal death was 10 out of 1000 compared to a less than one out of 1000 among multiparous women with no risk factors.”

Cheyney continues:

“To complicate matters, among women laboring after a cesarean with no prior vaginal birth, the repeat cesarean rate was just over 22%, which is less than our overall national cesarean rate of 32%. This means that 78% of women in this higher risk group had a vaginal birth! Pregnant people with this risk factor who are considering a community birth are forced to navigate a complex balance of risks and benefits associated with laboring after a cesarean in a community setting.”

Navigating through the research to understand the benefits and risks of any birth setting can be a challenge. Have questions? Ask us.

Read the rest of McCullough and Cheyney’s interview

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