Maternal Spleen Size Throughout Normal Pregnancy
Ron Maymon, MD,* Ariel L. Zimerman, MD,* Simon Strauss, MB ChB,*
and Gabriela Gayer, MD*
Ultrasonography (US) is an accurate method with reproducible results for calculating
splenic dimensions. Standards of normal spleen sizes have been developed for the general
adult population, for children, and even for tall healthy athletes, thereby enabling US diag-
nosis of splenomegaly. Extrapolation of data from the normal population to pregnant women
might, however, be inaccurate because of the physiological changes throughout gestation. We
have recently reported a prospective study evaluating the size of the maternal spleen through-
out pregnancy and hereby review the results and their implications.
Semin Ultrasound CT MRI 28:64-66 © 2007 Elsevier Inc. All rights reserved.
omen in the puerperium are infrequently imaged.
When, however, a patient becomes febrile after deliv-
ery, particularly following a cesarean section, computed to-
mography (CT) is often performed to evaluate for a possible
source of illness (eg, ovarian vein thrombosis, pelvic abscess,
We have observed repeatedly that women undergoing CT
within days after delivery tend to have a mildly enlarged
spleen (Fig. 1). We did not ﬁnd any data in the literature
regarding enlargement of the spleen in pregnant women.
Such enlargement may indicate a wide range of pathological
processes, necessitating additional work-up to establish the
exact cause. If, however, this enlargement is merely a tran-
sient physiological process, then it should be recognized as a
normal occurrence and not warrant any further evaluation.
We decided to investigate this observation, to conﬁrm that
the enlargement represents a physiological process. In addi-
tion we aimed to establish the normal range of maternal
spleen size throughout uncomplicated pregnancy. Due to its
noninvasive nature, ultrasonography (US) was used as the
imaging modality to assess spleen size.
Enlargement During Pregnancy
We have recently published a prospective study, which, to
the best of our knowledge, is the ﬁrst study to evaluate and
establish normal spleen size variation among healthy preg-
nant women throughout their pregnancy.
In this report we
examined a consecutive series of 288 apparently healthy
pregnant women between 6 and 42 weeks of normal preg-
nancy. All the women were scanned routinely for the purpose
of determining fetal viability, conducting biometry, or ruling
out fetal anomalies. The gestational age was calculated from
the ﬁrst day of the last menstrual period (LMP) and later
conﬁrmed by fetal biometric measurements.
Patients with a history of splenectomy, any history of fe-
brile illness within the past 6 months, malignancy, hemato-
logic disorder, chronic fatigue syndrome, or any other med-
ical disorder were excluded from the study. In addition, cases
with uncertain gestational age, multiple gestation, and any
known fetal malformation or chromosomal abnormality were
The spleen was measured with the woman placed in the
right lateral decubitus position and scanned during sus-
pended inspiration. Splenic length was deﬁned as the maxi-
mum length of the spleen in the coronal plane. Splenic width
was obtained by measuring the maximum diameter at a point
perpendicular to the length
In addition to measurements of the spleen, the other data
collected for each participant included maternal age, and
gestational age (by LMP), as well as maternal height (cm) and
weight (kg) before pregnancy for calculation of the pregesta-
tional body mass index (BMI). Height and weight values al-
low the calculation of BMI [weight/height (m
)]. The product
of spleen length ϫ spleen width was considered to reﬂect
spleen area. Association between spleen length, width and
area, and the two variables, BMI and gestational age, was
assessed using the Pearson correlation coefﬁcient.
A signiﬁcant correlation was found between gestational
age and splenic dimensions: length, width, and area. Simi-
*Department of Obstetrics and Gynecology.
†Department of Radiology, Assaf Harofe Medical Center, Zeriﬁn, Israel (af-
ﬁliated with the Sackler Faculty of Medicine, Tel-Aviv University, Tel-
Address reprint requests to Ron Maymon, MD, Department of Obstetrics
and Gynecology, Assaf Harofe Medical Center, Zeriﬁn 70300, Israel.
0887-2171/07/$-see front matter © 2007 Elsevier Inc. All rights reserved.