Location: Obesity and Metabolism ResearchTitle: Maternal cortisol and stress are associated with birth outcomes, but are not affected by lipid-based micronutrient supplements during pregnancy: an analysis of data from a randomized controlled trial in rural Malawi Author
|Stewart, Christine - University Of California|
|Oakes, Brietta - University Of California|
|Ashorn, Ulla - University Of Tampere|
|Harjunmaa, Ulla - University Of Tampere|
|Kumwenda, Chiza - University Of Tampere|
|Chaima, David - University Of Malawi|
|Maleta, Kenneth - University Of Malawi|
|Ashorn, Per - University Of Tampere|
|Dewey, Kathryn - University Of California|
Submitted to: BMC Pregnancy & Childbirth
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/11/2015
Publication Date: 12/22/2015
Citation: Stewart, C.P., Oakes, B.M., Laugero, K.D., Ashorn, U., Harjunmaa, U., Kumwenda, C., Chaima, D., Maleta, K., Ashorn, P., Dewey, K.G. 2015. Maternal cortisol and stress are associated with birth outcomes, but are not affected by lipid-based micronutrient supplements during pregnancy: an analysis of data from a randomized controlled trial in rural Malawi. BMC Pregnancy & Childbirth. 15:346. doi: 10.1186/s12884-015-0793-8.
Interpretive Summary: Low birth weight and premature birth are risk factors for poor health. Adequate nutrition in the mother is a key element that can influence gestation length and overall health of the newborn. Cortisol is annother factor during gestation we believe is influenced by maternal nutrition and thought to influence gestation length and birth weight. This study was a nutrition intervention which examined the effects of a lipid based nutrient supplement on salivary cortisol concentrations in the pregnant mother. This study tested whether women who receive lipid-based micronutrient supplements (LNS) during pregnancy would have lower salivary cortisol concentration at 28 wk and 36 wk gestation compared to micronutrients alone or iron-folic acid and if both salivary cortisol and perceived stress during pregnancy would be associated with shorter duration of gestation and smaller size at birth. Higher cortisol was strongly associated with lower size at birth and duration of gestation. However, we did not find that LNS provision to pregnant women influenced their salivary cortisol concentrations.
Technical Abstract: Background: Prenatal micronutrient supplements have been found to increase birth weight, but mechanisms for increased growth are poorly understood. Our hypotheses were that 1) women who receive lipid-based micronutrient supplements (LNS) during pregnancy would have lower salivary cortisol concentration at 28 wk and 36 wk gestation compared to multiple micronutrient (MMN) and iron-folic acid (IFA) supplement groups and 2) both salivary cortisol and perceived stress during pregnancy would be associated with shorter duration of gestation and smaller size at birth. Methods: Women were enrolled in the trial in early pregnancy and randomized to receive LNS, MMN, or iron-folic acid (IFA) supplements daily throughout pregnancy. At enrollment, 28 wk and 36 wk gestation, saliva samples were collected and cortisol concentration was measured. Self-report of perceived stress was measured using questionnaires. Gestation duration was indicated by ultrasound dating and newborn anthropometric measurements (weight, length, head circumference) provided indicators of intrauterine growth. Results: Of the 1391 women enrolled in the trial, 1372, 906 and 1049 saliva samples were collected from women at baseline, 28 wk and 36 wk, respectively. Although the baseline cortisol values were higher in the LNS group than in the MMN or IFA (p=0.032), there were no significant differences in mean cortisol concentrations by intervention group at 28 wk or 36 wk gestation. Cortisol concentrations were negatively associated with duration of gestation (Baseline: ß=-0.05, p=0.039; 36 wk: ß=-0.04, p=0.037) and birth weight (28 wk: ß=-0.08, p=0.035; 36 wk: ß=-0.11, p=0.003). The association between cortisol and birth weight-for-age z-score was modified by parity (p=0.034) with evidence of a strong association among primiparous women only. There were no significant associations with the risk of small for gestational age, preterm birth, or low birth weight. Conclusions: Although cortisol was strongly associated with size at birth and duration of gestation, these data do not support the hypothesis that LNS provision to pregnant women would influence their salivary cortisol concentrations.