Morning sickness linked to hCG hormone, psychological factors

Elevated levels of human chorionic gonadotropin (hCG) as well as a history of depression and increased depressive symptoms in the twelfth to fourteenth week of gestation contribute to a higher likelihood of having nausea and vomiting during pregnancy (NVP), a study has found.

Researchers obtained blood chemistry and psychological measures in 1,682 pregnant women enrolled in the Holistic Approach to Pregnancy and the first Postpartum Year (HAPPY) study between 12 and 14 weeks of gestation.

The Pregnancy-Unique Quantification of Emesis scale was used to assess the presence of NVP, while the Edinburgh Depression Scale facilitated evaluation of depressive symptoms. Multivariable logistic regression analyses were conducted to examine the role of hormones and psychological factors in NVP. Age, body mass index, education, parity, smoking status, unplanned pregnancy and history of depression were factored in as potential confounders.

A total of 318 (18.9 percent) women exhibited elevated levels of NVP. NVP had a positive, independent association with hCG concentration (odds ratio [OR], 1.47, 95 percent confidence interval [CI], 1.11–1.95), depressive symptoms in the first trimester (OR, 1.67, 95 percent CI, 1.15–2.43) and a history of depression (OR, 1.53, 95 percent CI, 1.11–2.11).

High NVP was also associated with multiparity (OR, 1.47, 95 percent CI, 1.12–1.92) and younger age (OR, 0.91, 95 percent CI, 0.87–0.94) but not with (sub)clinical hyperthyroidism.

The present data support the theory of a cognitive component in NVP and underscore a need for a multidisciplinary approach, according to the researchers. Screening for depressive symptoms in women experiencing morning sickness and subsequent referral for psychological interventions may help reduce NVP symptoms and minimize its effect on quality of life, functioning and healthcare costs.