Third-trimester routine ultrasound provides limited benefits
A routine ultrasound during the third trimester of pregnancy did not significantly affect pregnancy-related anxiety or mother-to-infant bonding, according to results of a pragmatic cluster-randomized controlled trial conducted in the Netherlands.
“In case of no abnormalities, [ultrasounds are] believed to provide reassurance about the
well-being of the child and thereby reduce pregnancy-specific anxiety levels,” Myrte Westerneng, PhD, a visiting fellow in midwifery science at Amsterdam University Medical Centers, and colleagues wrote in Birth. “In addition, getting a real-time image of their child has been suggested to contribute to prenatal mother-to-infant bonding.”
One in five women meets the diagnostic criteria for at least one peripartum anxiety disorder, according to data from a previously published meta-analysis. Westerneng and colleagues noted that “both pregnancy-specific anxiety and mother-to-infant bonding have received considerable attention over the years.”
In the new study, the researchers assigned 1,275 low-risk pregnant women receiving midwife-led care to an intervention group (n = 841) or a control group. In the intervention group, women were offered two additional ultrasounds to monitor fetal growth: one between 28 and 30 weeks gestation and the other between 34 and 36 weeks gestation. The ages of all women ranged from the late 20s to early 30s, and the majority were white.
Each woman received a questionnaire between 20 and 27 weeks gestation and again around 32 weeks gestation. The questionnaires incorporated the Pregnancy-Related Anxiety Questionnaire (maximum score = 50 points) and Maternal Antenatal Attachment Scale (maximum score = 95 points).
Westerneng and colleagues reported no significant difference in scores between the groups on the Pregnancy-Related Anxiety Questionnaire (20.14 points for intervention group vs. 19.94 points for control group) and Maternal Antenatal Attachment Scale (76.21 points for intervention group vs. 75.7 points for control group). Conversely, interaction analyses revealed that women with high levels of depressive symptoms at baseline and women who were very satisfied with the ultrasound procedure benefited somewhat more from the third-trimester routine ultrasound in terms of mother-to-infant bonding compared with women with low or no depressive symptoms, or less satisfied women, according to Westerneng and colleagues.
The researchers also noted that ultrasonography data were available for 487 women in the intervention group. Among this subcohort, 11.1% had ultrasounds with evidence of possible growth restriction, macrosomia or decreased amniotic fluid.
Collectively, the results suggest that “implementation of third-trimester routine ultrasound is currently not warranted,” Westerneng and colleagues wrote.