Pregnancy anxiety, placental corticotropin-releasing hormone and length of gestation

OBJECTIVE

High pregnancy anxiety is a consistent predictor of earlier labor and delivery. Placental corticotropin-releasing hormone (pCRH) predicts earlier delivery consistently and it has been identified as a biological mediator of the association between pregnancy anxiety and gestational length. However, studies have not examined whether changes in pregnancy anxiety are associated with earlier birth as mediated by changes in pCRH during pregnancy. Accordingly, this study tests whether linear changes in pregnancy anxiety are associated with length of gestation indirectly through nonlinear increases in pCRH over pregnancy.

METHODS

A sample of pregnant women (n=233) completed prenatal assessments in early pregnancy, second trimester, and third trimester that included a 4-item assessment of pregnancy anxiety and collection of blood samples assayed for pCRH using radioimmunoassay. Length of gestation was abstracted from medical records after birth.

RESULTS

Increases in pregnancy anxiety from early pregnancy to third trimester predicted shorted length of gestation, as did nonlinear increases in pCRH over pregnancy. However, there was no evidence of an indirect effect of changes in pregnancy anxiety on length of gestation via changes in pCRH.

CONCLUSIONS

These results indicate that linear changes in pregnancy anxiety and nonlinear changes in pCRH during pregnancy are independent risk factors for shortened gestational length. This study adds to a small but growing body of work on biopsychological processes in pregnancy and length of gestation. Modeling changes in psychological and biological processes during pregnancy could provide more insight into understanding risk for adverse pregnancy outcomes.

Impact of Immigration and Duration of Residence in US on Length of Gestation Among Black Women in Newark, New Jersey

Little is known about pregnancy outcomes of black immigrant women to the US. We surveyed 447 black women post-partum in two hospitals in Newark, NJ. Length of gestation was obtained from medical records. Covariates and information on immigration were collected by in-person interview. Risks ratios for preterm birth (< 37 weeks) comparing immigrant to US-born women were calculated using log-binomial regression. Associations with gestational age at delivery were estimated using linear regression. Multivariable models adjusted for socioeconomic and social/behavioral variables. Immigrant women relative to US-born women had a 60% lower risk of preterm birth (adjusted risk ratio = 0.4; 95% confidence interval (CI) 0.2, 0.8) and longer gestation (adjusted difference = 1.4 weeks, 95%CI 0.6, 2.1). Gestation was 1.9 weeks longer for recent immigrants compared to US-born women (95%CI 0.2, 3.6), whereas for those who lived in the US for at least 10 years there was no difference. The healthy immigrant effect found among black immigrants may erode with time in the US.

Pregnancy anxiety predicts shorter gestation in Latina and non-Latina white women: The role of placental corticotrophin-releasing hormone

OBJECTIVE

Previous research has shown that a woman's anxiety about her pregnancy predicts gestational length. Placental corticotrophin-releasing hormone (CRH) is a stress-responsive peptide proposed as a mechanism. We examined placental CRH as a physiological mediator of the association between pregnancy anxiety and gestational length in Latina and non-Latina White women to replicate evidence of associations between pregnancy anxiety, placental CRH and gestational length; to test whether placental CRH levels or changes mediate effects of pregnancy anxiety on gestational length; to examine ethnic differences in pregnancy anxiety, placental CRH, and gestational length; and to explore whether the effects of pregnancy anxiety on gestational length as mediated by placental CRH vary by ethnicity.

METHODS

In a prospective study of 337 pregnant Latina and non-Latina White women, participants completed in-person interviews that included a 10-item measure of pregnancy anxiety and provided blood samples assayed using radioimmunoassay at three timepoints (19, 25, and 31 weeks gestation).

RESULTS

Pregnancy anxiety at 19 and 31 weeks and levels of placental CRH at 31 weeks predicted gestational length. Tests of indirect effects were consistent with mediation such that both pregnancy anxiety at 19 weeks and increases from 19 to 31 weeks predicted placental CRH at 31 weeks, which in turn predicted gestational length. Tests of moderated mediation by ethnicity showed that the mediated effect of placental CRH at 31 weeks was significant for Latinas only.

CONCLUSIONS

These findings add to growing evidence of the involvement of pregnancy anxiety in the timing of birth, address mechanisms, and suggest possible ethnic differences.

Prenatal determinants of physical activity and cardiorespiratory fitness in adolescence - Northern Finland Birth Cohort 1986 study

BACKGROUND

Lower levels of physical activity and cardiorespiratory fitness are key risk factors of chronic adult diseases. Physical activity and cardiorespiratory fitness are predicted by birth weight, but the underlying parental and pregnancy-related factors remain largely unknown. We examined how prenatal determinants are associated with physical activity and cardiorespiratory fitness in adolescence.

METHODS

Of the 16-year-old members of the population-based Northern Finland Birth Cohort 1986 (NFBC 1986), 6682 singletons with no major physical disability reported their amount of physical activity outside school hours, and 4706 completed a submaximal cycle ergometer test assessing cardiorespiratory fitness. Physical activity was expressed as metabolic equivalent hours per week (METh/week) and cardiorespiratory fitness as peak oxygen uptake (ml·kg-1·min-1). Prenatal determinants included birth weight, length of gestation, mother's and father's body mass index (BMI), maternal gestational diabetes mellitus (GDM), and maternal hypertension and smoking during pregnancy. Data were analyzed by multiple linear regression.

RESULTS

A higher birth weight and longer length of gestation predicted lower levels of physical activity and cardiorespiratory fitness at 16 years, although the association between length of gestation and physical activity was inverse U-shaped. Mother's or father's overweight or obesity before pregnancy were associated with lower levels of their offspring's physical activity and fitness in adolescence. Adjusting for maternal pregnancy disorders and the adolescent's own BMI attenuated the associations with the mother's but not the father's overweight/obesity. Furthermore, maternal GDM predicted lower cardiorespiratory fitness.

CONCLUSIONS

A high birth weight and parental overweight/obesity are associated with lower levels of both physical activity and cardiorespiratory fitness in adolescence, while maternal GDM and longer length of gestation are associated with lower cardiorespiratory fitness. Both long and short lengths of gestation predict low physical activity.

Prenatal lignan exposures, pregnancy urine estrogen profiles and birth outcomes

During pregnancy, human exposure to endogenous estrogens and xenoestrogens (such as lignans) may comprehensively impact the gestational maintenance and fetal growth. We measured the concentrations of 5 lignans and the profile of 13 estrogen metabolites (EMs) in the urine samples of 328 pregnant women and examined their associations with birth outcomes. We found significantly positive associations between gestational age and urinary matairesinol (MAT), enterodiol (END) and enterolactone (ENL), as well as 16-hydroxylation pathway EMs. There were consistently positive relationships between END and the 16-hydroxylation pathway EMs. The positive relationships of MAT, END and ENL exposures with the length of gestation were mainly in the low exposure strata of the levels of these EMs. This study reveals that MAT, END and ENL as well as 16-hydroxylation pathway EMs are associated with birth outcomes, and that there are interactive relationships between lignans and 16-hydroxylation pathway EMs with birth outcomes.

Maternal positive affect over the course of pregnancy is associated with the length of gestation and reduced risk of preterm delivery

OBJECTIVE

The association between maternal psychological state during pregnancy and birth outcomes is well established. The focus of previous studies has been on the potentially detrimental consequences of maternal stress on pregnancy and birth outcomes, particularly shortened gestation and increased risk of preterm birth. Despite a growing literature linking positive affect with favorable health outcomes this construct has received little attention in the context of pregnancy. Therefore, in the current study, we tested the hypothesis that maternal positive affect during pregnancy is associated with beneficial consequences in terms of increased length of gestation and reduced risk of preterm birth above that of the absence of stress.

METHODS

In 169 pregnant women maternal positive affect and perceived stress were serially assessed at 15.2 ± 0.9 weeks (T1; mean ± SD), 19.7 ± 0.9 weeks (T2) and 30.7 ± 0.7 weeks (T3) gestation. Pregnancy and birth outcomes were abstracted from the medical record.

RESULTS

Higher maternal positive affect and a steeper increase in maternal positive affect over pregnancy were positively associated with length of gestation (p<.05) and reduced risk of preterm delivery (p<.01), whereas maternal perceived stress was not significantly associated with shorter length of gestation (p>.10).

CONCLUSIONS

These findings suggest that maternal positive affect may be beneficial for outcomes related to the length gestation, and that this effect cannot be accounted for by the lower stress levels associated with higher positive affect. Interventions to increase maternal positive affect may be beneficial for fetal development.