Psychometric properties of stress and anxiety measures among nulliparous women.
To examine the psychometric properties of three measures, the perceived stress scale (PSS), pregnancy experience scale (PES), and state trait anxiety inventory (STAI), for assessing stress and anxiety during pregnancy among a large sample of nulliparous women.



The sample included 10,002 pregnant women participating in the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be (nMoM2b). Internal consistency reliability was assessed with Cronbach's alpha and factorial validity with confirmatory factor analyses. Intraclass correlations (ICCs) were calculated to determine stability of PSS scales over time. Psychometric properties were examined for the overall sample, as well as subgroups based on maternal age, race/ethnicity and language.



All three scales demonstrated good internal consistency reliability. Confirmatory factor analyses supported the factor structures of the PSS and the PES. However, a one-factor solution of the trait-anxiety subscale from the STAI did not fit well; a two-factor solution, splitting the items into factors based on direction of item wording (positive versus negative) provided a better fit. Scores on the PSS were generally stable over time (ICC = 0.60). Subgroup analyses revealed a few items that did not perform well on Spanish versions of the scales.



Overall, the scales performed well, suggesting they could be useful tools for identifying women experiencing high levels of stress and anxiety during pregnancy and allowing for the implementation of interventions to help reduce maternal stress and anxiety.
a Division of Statistical and Data Sciences , RTI International, Research Triangle Park , NC , USA.
Carla M
CM
Bann
b Biostatistics and Epidemiology Division , RTI International, Research Triangle Park , NC , USA.
Corette B
CB
Parker
c Department of Obstetrics & Gynecology , Northwestern University , Chicago , IL , USA.
William A
WA
Grobman
d Eunice Kennedy Shriver National Institute of Child Health and Human Development , Bethesda , MD , USA.
Marian
M
Willinger
e Department of Obstetrics, Gynecology & Reproductive Sciences , University of Pittsburgh , Pittsburgh , PA , USA.
Hyagriv N
HN
Simhan
f Department of Obstetrics & Gynecology , University of California at Irvine , Irvine , CA , USA.
Deborah A
DA
Wing
g Department of Obstetrics & Gynecology , Indiana University , Indianapolis , IN , USA.
David M
DM
Haas
h Department of Obstetrics & Gynecology , University of Utah , Salt Lake City , UT , USA.
Robert M
RM
Silver
i Department of Obstetrics & Gynecology , University of Pennsylvania , Philadelphia , PA , USA.
Samuel
S
Parry
j Department of Obstetrics & Gynecology , University of Texas Medical Branch-Galveston , Galveston , TX , USA.
George R
GR
Saade
k Department of Obstetrics & Gynecology , Columbia University , New York , NY , USA.
Ronald J
RJ
Wapner
i Department of Obstetrics & Gynecology , University of Pennsylvania , Philadelphia , PA , USA.
Michal A
MA
Elovitz
l Department of Obstetrics & Gynecology , Northwestern University , Chicago , IL , USA.
Emily S
ES
Miller
d Eunice Kennedy Shriver National Institute of Child Health and Human Development , Bethesda , MD , USA.
Uma M
UM
Reddy
D000328:Adult; D001007:Anxiety / Q000175:diagnosis*; D005260:Female; D006801:Humans; D010298:Parity; D011247:Pregnancy; D011248:Pregnancy Complications / Q000175:diagnosis*; D037841:Pregnant People / Q000523:psychology*; D011569:Psychiatric Status Rating Scales / Q000592:standards*; D011594:Psychometrics / Q000295:instrumentation*; D013315:Stress, Psychological / Q000175:diagnosis*; D055815:Young Adult
Anxiety; parity; psychometrics; stress