Interventions reduce chance that at-risk infants will be born small for gestational age

A structured Mediterranean diet or mindfulness-based stress reduction therapy, compared with usual care, significantly reduced the proportion of newborns at risk for low birth weight being born below the 10th percentile, data showed.

“In pregnancy, small studies have reported that [mindfulness-based] stress reduction was feasible and associated with lower perceived stress and anxiety,” Francesca Crovetto, MD, PhD, a post-doctoral fellow at the BCNatal Fetal Medicine Research Center in Barcelona, Spain, and colleagues wrote in JAMA. “However, no studies have evaluated the effect of [mindfulness-based] stress reduction on pregnancy outcomes.”

Crovetto and colleagues randomly assigned 1,221 women with singleton pregnancies in a 1:1:1 ratio to receive one-on-one and group educational sessions 2 hours a month plus free provision of extra-virgin olive oil and walnuts twice a month (Mediterranean diet cohort); participate in an 8-week mindfulness stress reduction program modified to help those who were pregnant (stress reduction cohort); or receive usual care. The ages of the women ranged between 33.2 and 40.5 years. They were enrolled from a single institution, were between 19 and 23 weeks pregnant and at high risk for having an infant who was small for gestational age. The majority of the women in the trial were white and had a mean pre-pregnancy BMI of about 24 kg/m². More than 90% of each cohort completed the trial.

Crovetto and colleagues reported that 21.9% of newborns in the usual care cohort, 14% of infants in the Mediterranean diet cohort (OR = 0.58; 95% CI, 0.4-0.84; risk difference = –7.9; 95% CI, –13.6 to –2.6) and 15.6% of those in the mindfulness stress reduction cohort (OR = 0.66; 95% CI, 0.46-0.94; risk difference = –6.3; 95% CI, –11.8 to –0.9) were born small for their gestational age.

In addition, the composite adverse perinatal outcome — a woman giving birth at fewer than 37 weeks’ gestation, preeclampsia, perinatal mortality, birthweight below the third percentile, neonatal acidosis, Apgar score below seven at 5 minutes or “any major neonatal morbidity — took place in 26.2% of the usual care cohort, 18.6% of the Mediterranean diet cohort (OR = 0.64; 95% CI, 0.46-0.9; risk difference = –7.6; 95% CI, –13.4 to –1.8) and 19.5% in the stress reduction cohort (OR = 0.68; 95% CI, 0.49-0.95; risk difference = –6.8; 95% CI, –12.6 to –0.3).

According to Crovetto and colleagues, the findings are subject to multiple limitations, including a smaller than expected effect size on the usual care cohort, a surplus number of early births in the usual care cohort “clustered extremely early in the intervention period,” uncertainty that study participants all had the same number of health care-related visits. Study participation was also limited to those with high-risk pregnancies with “low participation” of study participants who had obesity, gestational diabetes and large-for-gestational-age newborns.

“Due to [these] important study limitations, these findings should be considered preliminary and require replication, as well as assessment in additional patient populations, before concluding that these treatments should be recommended to patients,” the researchers wrote.

In a related editorial, Margaret Bublitz, PhD, an assistant professor of psychiatry and human behavior and assistant professor of medicine at Brown University, and Methodius G. Tuuli, MD, MPH, MBA, the executive chief of obstetrics and gynecology for Women & Infants Hospital in Rhode Island, and chair of the department of obstetrics and gynecology at the Warren Alpert Medical School at Brown University, wrote that Crovetto and colleagues’ findings were novel, particularly “since there is no proven intervention for prevention of [small gestational age]” infants.

However, they also recommended future research in this clinical area before physicians recommend the studied approaches to their patients with similar characteristics.

“Implementation of these interventions into clinical practice should await results of the neurodevelopmental assessment and other outcomes among the offspring at 2 years of age and replication of the study results in other populations,” Bublitz and Tuuli wrote.

References:

Bublitz M, Tuuli MG. JAMA. 2021;326(21):2137-2138.

Crovetto F, et al. JAMA. 2021;doi:10.1001/jama.2021.2017.