Isolated gestational proteinuria preceding the diagnosis of preeclampsia - an observational study.
BACKGROUND
Some pregnant women develop significant proteinuria in the absence of hypertension. However, clinical significance of isolated gestational proteinuria (IGP) is not well understood. This study aimed to determine the prevalence of IGP in singleton pregnancies and the proportion of women with IGP who subsequently developed preeclampsia (IGP-PE) among all PE cases.


METHODS
This was an observational study of 6819 women with singleton pregnancies at 12 centers, including 938 women with at least once determination of protein-to-creatinine ratio (P/Cr). Significant proteinuria in pregnancy (SPIP) was defined as P/Cr (mg/mg) level >0.27. IGP was defined as SPIP in the absence of hypertension. Gestational hypertension (GH) preceding preeclampsia (GH-PE) was defined as preeclampsia (PE) in which GH preceded SPIP. Simultaneous PE (S-PE) was defined as PE in which both SPIP and hypertension occurred simultaneously.


RESULTS
IGP and PE were diagnosed in 130 (1.9%) and 158 (2.3%) of 6819 women, respectively. Of 130 women with IGP, 32 (25%) progressed to PE and accounted for 20% of all women with PE. Hence, women with IGP had a relative risk of 13.1 (95% CI; 9.2-18.5) for developing PE compared with those without IGP [25% (32/130) vs. 1.9% (126/6689)]. At diagnosis of SPIP, P/Cr levels already exceeded 1.0 more often in women with S-PE than in those with IGP-PE [67% (33/49) vs. 44% (14/32), respectively, p = 0.031].


CONCLUSIONS
IGP is a risk factor for PE, and IGP-PE accounts for a considerable proportion (20%) of all PE.
Department of Obstetrics and Gynecology, Hokkaido University Hospital, Sapporo, Japan.
Takahiro
http://orcid.org/0000-0002-5370-7873
T
Yamada
Department of Obstetrics and Gynecology, University of Tsukuba Hospital, Tsukuba, Japan.
Mana
http://orcid.org/0000-0002-7663-1808
M
Obata-Yasuoka
Department of Obstetrics and Gynecology, University of Tsukuba Hospital, Tsukuba, Japan.
Hiromi
http://orcid.org/0000-0002-0560-7034
H
Hamada
Department of Obstetrics and Gynecology, Jichi Medical University Hospital, Shimotsuke, Japan.
Yosuke
http://orcid.org/0000-0001-9807-9535
Y
Baba
Department of Obstetrics and Gynecology, Jichi Medical University Hospital, Shimotsuke, Japan.
Akihide
http://orcid.org/0000-0002-8861-1572
A
Ohkuchi
Department of Obstetrics and Gynecology, Fukushima Medical University Hospital, Fukushima, Japan.
Shun
http://orcid.org/0000-0002-6520-902X
S
Yasuda
Department of Obstetrics and Gynecology, Hakodate Central General Hospital, Hakodate, Japan.
Kosuke
http://orcid.org/0000-0001-6167-2984
K
Kawabata
Department of Obstetrics and Gynecology, Hiroshima University Hospital, Hiroshima, Japan.
Shiori
http://orcid.org/0000-0002-9992-7900
S
Minakawa
Department of Obstetrics and Gynecology, Juntendo University Hospital, Tokyo, Japan.
Chihiro
http://orcid.org/0000-0002-6612-4407
C
Hirai
Department of Obstetrics and Gynecology, Mie Chuo Medical Center, Tsu, Japan.
Hideto
http://orcid.org/0000-0003-3840-7116
H
Kusaka
Department of Obstetrics and Gynecology, Mie University Hospital, Tsu, Japan.
Nao
http://orcid.org/0000-0002-5799-6764
N
Murabayashi
Department of Obstetrics and Gynecology, Medical School Tama Nagayama Hospital, Tama, Japan.
Yusuke
http://orcid.org/0000-0002-4478-5650
Y
Inde
Department of Obstetrics and Gynecology, Rakuwakai Otowa Hospital, Kyoto, Japan.
Michikazu
http://orcid.org/0000-0001-9577-4380
M
Nagura
Department of Obstetrics and Gynecology, Hokkaido University Hospital, Sapporo, Japan.
Takeshi
http://orcid.org/0000-0001-9236-9945
T
Umazume
Department of Obstetrics and Gynecology, Juntendo University Hospital, Tokyo, Japan.
Atsuo
http://orcid.org/0000-0002-4554-164X
A
Itakura
Department of Obstetrics and Gynecology, Mie Chuo Medical Center, Tsu, Japan.
Makoto
http://orcid.org/0000-0001-5860-9204
M
Maeda
Department of Obstetrics and Gynecology, Rakuwakai Otowa Hospital, Kyoto, Japan.
Norimasa
http://orcid.org/0000-0003-4130-2905
N
Sagawa
Department of Obstetrics and Gynecology, Ohno Ladies Clinic, Iwakura, Japan.
Yasumasa
http://orcid.org/0000-0002-0959-7523
Y
Ohno
Department of Obstetrics and Gynecology, Hakodate Central General Hospital, Hakodate, Japan.
Soromon
http://orcid.org/0000-0001-7197-8258
S
Kataoka
Department of Obstetrics and Gynecology, Fukushima Medical University Hospital, Fukushima, Japan.
Keiya
http://orcid.org/0000-0001-8618-4063
K
Fujimori
Department of Obstetrics and Gynecology, Hiroshima University Hospital, Hiroshima, Japan.
Yoshiki
http://orcid.org/0000-0001-6542-3408
Y
Kudo
Department of Obstetrics and Gynecology, Mie University Hospital, Tsu, Japan.
Tomoaki
http://orcid.org/0000-0003-1489-4810
T
Ikeda
Department of Obstetrics and Gynecology, Medical School Tama Nagayama Hospital, Tama, Japan.
Akihito
http://orcid.org/0000-0002-9193-0443
A
Nakai
Department of Obstetrics and Gynecology, Hokkaido University Hospital, Sapporo, Japan.
Hisanori
http://orcid.org/0000-0002-6761-7502
H
Minakami
D000293:Adolescent; D000328:Adult; D003404:Creatinine / Q000652:urine; D005260:Female; D006801:Humans; D046110:Hypertension, Pregnancy-Induced / Q000453:epidemiology; D007564:Japan / Q000453:epidemiology; D008423:Maternal Age; D008875:Middle Aged; D011225:Pre-Eclampsia / Q000175:diagnosis / Q000453:epidemiology*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology*; D011507:Proteinuria / Q000453:epidemiology*; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult
D003404:Creatinine
Disease pregnancy; preeclampsia; pregnancy outcome; protein to creatinine ratio; proteinuria pregnancy