FERTILITY AND STERILITY
Copyright 2001 American Society for Reproductive Medicine
Printed on acid-free paper in U.S.A. Effect of a combined oral contraceptive containing 3 mg of drospirenone and 30
g of ethinyl estradiol on the human endometrium Frank Lu¨dicke, M.D.,a Elisabeth Johannisson, M.D.,a Frans M. Helmerhorst, M.D.,bAldo Campana, M.D.,a Jean-Michel Foidart, M.D.,c and Renate Heithecker, Ph.D.d
University Hospital Geneva, Geneva, Switzerland; Leiden University Medical Center, Leiden, The Netherlands;Universite´ de Lie`ge CHR Citadelle, Lie`ge, Belgium; and Schering AG, Berlin, GermanyObjective: To provide an in-depth assessment of the effects of the combined oral contraceptive containing 30 g of ethinyl estradiol and 3 mg of drospirenone (Yasmin, Schering AG, Berlin) on the endometrium by means of endometrial morphometry in comparison to an untreated cycle. Design: The open, multicenter study consisted of one untreated precycle and 13 treatment cycles. Setting: Four gynecologic clinics in Belgium, The Netherlands, and Switzerland were involved. Patient(s): Forty women with a history of regular menstrual cycles. Intervention(s): Before the commencement of the trial, 3 months without any hormonal intake was oblig- atory. The first endometrial sample was done in the untreated precycle, adjusted to the day of LH peak plus 5 to 6 days. During the medication phase, endometrial samples were taken at cycle 3, 6 and 13. Main Outcome Measure(s): Primary outcome measure of the study was the morphologic assessment of the endometrium with measures such as glandular diameter, glandular epithelial height, and number of vacuolated cells per 1,000 glandular cells. Furthermore, the endometrial thickness was measured by ultrasound. Result(s): After 13 cycles of medication use the endometrium had an atrophic appearance in 63% of the
subjects. The size of the glands, the glandular epithelial height, and the number of glands per square millimeter
were already significantly reduced after 3 months’ use. Histological and ultrasonographical evaluation of the
endometrium indicated a suppression of the proliferative activity of the endometrium. Conclusion(s): The combination of 30 g of ethinyl estradiol with 3 mg of drospirenone induces changes of
the endometrium that are comparable with other combined oral contraceptives and exhibits a marked
antiproliferative effect on the endometrium. The medication was proven to be an effective oral contraceptive
and revealed good cycle control characteristics. (Fertil Steril 2001;76:102–7. 2001 by American Society for
Hospital Geneva,Switzerland, 30 bld de la
Key Words: Combined oral contraceptive, drospirenone, endometrium
Cluse, 1211 Geneva 14,Switzerland. a Department of Obstetricsand Gynecology, University
erts antimineralocorticoid effects in humans (3,
chemically a 17-␣-spirolactone derivative, was
4). DRSP given in a dosage of 2 mg inhibits
characterized in receptor-binding studies and in
ovulation in normally cycling women and has
transactivation assays as a progestogen with
shown to increase sodium excretion when com-
Reproductive Medicine,Leiden University Medical
antimineralocorticoid and antiandrogenic ac-
pared with placebo. This mild natriuretic effect
tivity and was found to be devoid of any an-
of DRSP is expected to be of potential benefit
drogenic, estrogenic, glucocorticoid, and anti-
in terms of prevention of sodium retention and
Gyne´cologie-Obste´triquede l’Universite´ de Lie`ge
glucocorticoid activity (1). These in vitro
rise in blood pressure in susceptible women
findings were in accordance with the pharma-
cological profile found by in vivo studies in
medication (5, 6). The antiandrogenic activity
Fertility Control & HormoneTherapy, Schering AG.
various animal models (2). These characteris-
of DRSP is due to a functional blockade of the
tics place DRSP in close resemblance to the
androgen receptor, and the potency in vivo in
0015-0282/01/$20.00PII S0015-0282(01)01834-9
natural hormone progesterone, which also ex-
the rat was found to be one-third that of cypro-
terone acetate (2). Both the antimineralocorticoid and anti-androgenic effects of DRSP made it a promising candidate
for further drug development as progestogenic agent for oral
Baseline characteristics of age, height, weight, age at
contraception and hormone replacement therapy.
menarche and intracyclic bleeding before the start of the
The progestogenic activity of DRSP was evaluated in a
variety of animal models, and the results obtained suggest a
relative progestational potency of the same order as that ofnorethisterone acetate (2). The borderline ovulation inhibi-
tion dose in women was found to be 2 mg and the combi-
nation of 30 g of ethinyl estradiol (EE) and 3 mg of DRSP
did enter into the clinical development of the COC (7). In
addition to ovulation inhibition, the contraceptive effect by
oral contraceptives are attained by induced changes of the
endometrium hampering ovum implantation. The adminis-
Note: Data given as mean Ϯ standard deviation.
tration of a COC produces variable histological pictures, but
Lu¨dicke. Combined oral contraceptive and human endometrium. Fertil Steril 2001.
in general, results in an underdevelopment of endometrialstroma and glands, whereas the effect on the endometrialglands are often more pronounced. The endometrium be-
gave her written consent before enrollment. The study was
comes scanty and contains only few glands with empty and
performed with the regulations and recommendation of the
narrow-lined lumina (8). With time of COC intake, the
Declaration of Helsinki (Hong Kong 1989).
height of the epithelium decreases, the glands become atro-
Episodes of bleeding and any adverse events were re-
phic, pseudodezidualisation of the stroma can be detected,
and, moreover, the development of the spiral arteries does
Trial Plan
not take place to the same extent as in a normal menstrual
The women who volunteered for the study were assigned
randomly to two independent groups. In group A, the treat-
These induced changes in the endometrium are consid-
ment effects were investigated after 3 and 13 treatment
ered to avoid hyperplasia and to minimize the long-term risk
cycles. In group B, the treatment effects were investigated
for endometrial cancer and could also lead to less menstrual
after 6 and 13 treatment cycles. Both groups received the
bleeding. In the study reported here, the degree to which the
same medication, thus the only difference between the two
DRSP-containing oral contraceptive affects the endome-
assessment groups was the timing of the endometrial biop-
trium in healthy women was investigated; it was aimed at
assessing the effects of the combined oral contraceptive
The study consisted of one untreated precycle and 13
containing 30 g of EE and 3 mg of DRSP on the endome-
treatment cycles. Before the commencement of the trial, a
trium by means of endometrial morphometry in comparison
minimum of 3 months without any hormonal intake was
to an untreated cycle. Evaluation of the effect of the study
obligatory. The first endometrial sample in the untreated
medication on the endometrium characterizes the progesta-
precycle was performed adjusted to the day of LH peak plus
tional potency of DRSP, and the results were compared to
5 to 6 days. A home monitoring kit to detect the LH peak in
already existing data on endometrial changes with other
urine (OvuQuick, Quidel, San Diego, CA) was used for this
combined oral contraceptives. Finally, the gathered data
purpose. Baseline characteristics for all 40 subjects are sum-
adds valuable information to the safety evaluation of this
Test Material MATERIALS AND METHODS
The study medication consisted of 21 film-coated tablets
of 30 g of ethinyl estradiol and 3 mg of drospirenone per
Subjects
blister pack. One tablet was taken daily for 21 days, followed
Forty apparently healthy women with a history of regular
menstrual cycles volunteered for the study. None of them
Endometrial Samples and Morphometric
had used steroidal contraceptives or an intrauterine device
Analyses
during the previous 3 months, and none had had an abortion
The endometrial sample was performed with a Pipelle de
within the last 6 months or delivery within 1 year before
cornier device without dilatation of the cervix and without
anesthesia. The endometrial strips (10 –15 mm) were imme-
The medical ethics committee of each of the study sites
diately fixed, embedded in paraffin, sectioned, and stained
(Geneva, Switzerland; Leiden, The Netherlands; Lie`ge and
with hematoxylin and eosin. In addition to a general histo-
Nijmegen, Belgium) approved the study, and each woman
logic assessment of the endometrial biopsies, numeric data
FERTILITY & STERILITY
difference was seen concerning the histologic assessment
between VCA and ITT population. No endometrial pathol-ogy was detected in the ITT nor in the VCA population. For
Morphological indices applied for the trial.
the morphometric parameters, the VCA is reported only. Disposition of Study Subjects
After having given informed consent, 40 women were
assigned to two different groups according to a list reflecting
the different time points of the intermediate biopsy, 19
subjects to group A (intermediate biopsy cycle 3) and 21
subjects to group B (intermediate biopsy cycle 6). Two
a Score 0 –3; 0 ϭ none, 1 ϭ slight, 2 ϭ moderate, and 3 ϭ marked.
women initially assigned to group A were erroneously
Lu¨dicke. Combined oral contraceptive and human endometrium. Fertil Steril 2001.
switched to group B before the their first intermediate bi-opsy, so that they were evaluated in group B; thus, a total of40 subjects were included in the ITT analysis: 17 were
was generated on morphometric parameters of the endome-
evaluated in group A and 23 in group B. Intermenstrual
trium so as to obtain quantitative information about the
bleeding characteristics and adverse events during the course
endometrial morphology. The indices examined are shown
of the study were evaluated by the ITT analysis.
Seven women discontinued the trial prematurely, in six
Ultrasound Examination of the Endometrium
women, the endometrial biopsy at baseline or in treatment
At each study visit, a transvaginal sonographical exami-
cycle 13 was not available or yielded not sufficient material,
nation of the endometrium was done with the use of high
and one woman was excluded from the analysis because she
frequency (5–7 MHz) transducers. Endometrial thickness
switched accidentally to a different COC; therefore, 26 cases
was measured as the distance between both endometrial/
entered into the valid case analysis, 13 subjects in each
group. Some of the biopsies during treatment resulted in toofew material for morphometric evaluation, thus, at cycle
Statistical Analysis
three, 11 biopsies, and at cycle six, 10 biopsies, were evalu-
The primary target variables were the individual changes
from baseline (precycle) to the 3rd, 6th, and 13th treatmentcycle of the diameter of glands, the height of the glandular
Intermenstrual Bleeding
epithelium, and the number of vacuolated glandular cells.
Bleeding that occurred outside the tablet-free interval was
All other morphological indices variables were considered
described as intermenstrual bleeding, presenting either as
secondary target variables (Table 2).
scanty bleeding (spotting) or with the strength of a menstrualperiod (breakthrough bleeding). Thirteen women reported
The two-sided 95% confidence intervals were computed
spotting in the first treatment cycle. The incidence of spot-
under the assumption of normal deviates for all variables
ting declined continuously afterwards. Nineteen subjects re-
except to the score variables pseudostratification and prede-
ported intermenstrual bleeding at least once from the second
to the 13th cycle. One woman reported an episode of break-
Intention-to-Treat and Valid Case Analyses
through bleeding during the treatment period. No correlation
Two types of analyses were done: a valid-case (VCA)
between episodes of intermenstrual bleeding and the mor-
analysis for the primary outcome measures and an intention-
phometric assessment of the endometrium was detected.
to-treat (ITT) analysis on all variables in addition to the VCA. Adverse Events
A subject was reckoned as a valid case if she had no
Three women discontinued the trial because of the fol-
protocol deviation that might have affected the primary
lowing adverse events: acne, headache, and weight gain. The
outcome measures of the trial, meaning the morphologic
most frequently mentioned complaints during drug intake
assessment of the endometrium. According to the study
were headache (eight cases), breast tension (five cases), and
protocol, the following criteria had to be fulfilled: at least
one biopsy at baseline and at the end of the study had to beexistent, not more than four missed pills in each medication
Morphometry
cycle were allowed, and the months without hormonal med-
According to the collected tissue samples at baseline, all
ication before the trial had to be adhered to. In contrary, the
26 women showed a histologically secretory endometrium,
only prerequisite for a subject to be included into the ITT
which contained glands in which the epithelial cells exhib-
analysis was that she had taken at least one pill. No notable
ited sub- or supranuclear vacuolization or showed apocrine-
Lu¨dicke et al.
A combined oral contraceptive and human endometrium
Indices of endometrial morphology before (pre-cycle) and during administration of 3 mg of DRSP and 30 g of EE. Note: Data given as mean Ϯ SD; (mean absolute change from pre-cycle Ϯ SD); [Confidence interval for mean change from pre-cycle]. Lu¨dicke. Combined oral contraceptive and human endometrium. Fertil Steril 2001.
type secretion into the gland lumina. During treatment, an
lated cells. At the baseline biopsy in one case, “slight pre-
increasing atrophy of the endometrium was found, as char-
decidualization” was scored. During treatment, two histolo-
acterized by small glands with a single layer of inactive
gies were reported with signs of slight predecidualization,
epithelium, without mitotic figures or secretory activity, and
two cases with moderate predecidualization, and one case
no evidence of decidual changes. The endometrium appeared
with marked predecidualization. Except in one case, no
to be atrophic in 41% and 44% of women having used the
pseudostratification was seen under treatment.
medication for 3 and 6 cycles, respectively. After 13 cycles
Finally, the ultrasonographic measurements of the endo-
of COC use, atrophy was described in 63% of the cases.
metrium correlated well with the results of the morphometric
Table 3 summarizes the different morphometric indices
measurements and indicated a suppression of the endome-
and their change from baseline during the study period. A
trium. The full sonographic reduction of endometrial thick-
distinct suppression of proliferative activity of the functional
ness was reached after six cycles (Table 4).
layer of the endometrium was reflected by the reduced sizeof the glandular diameter compared with baseline duringtreatment. This effect was already seen after three cycles of
DISCUSSION
COC intake and was even more pronounced and statisticallysignificant at treatment cycle 6 and 13. Equally, a reduction
Throughout the normal menstrual cycle, the morphologic
of the number of glands and the gland’s epithelial height was
variation of the endometrium has been documented, and
found to be reduced when compared with baseline. A sig-
some of the major features of these changes that are also
nificant decrease in epithelial height was already observed at
represented in the morphometric indices applied for this
3 months of medication and remained in the same range at
study are schematically shown in Figure 1.
treatment cycle 6 and 13 (Table 3). The number of vacuo-
The number of glands per square millimeter is approxi-
lated cells per 1,000 glandular cells was suppressed to zero
mately 20 and does not change significantly during the
under treatment from a mean baseline value of 376 vacuo-
normal menstrual cycle, whereas the glandular diameter
Endometrial thickness (mm) as assessed by ultrasound—mean values and absolute changes. Lu¨dicke. Combined oral contraceptive and human endometrium. Fertil Steril 2001.FERTILITY & STERILITY
Selected endometrial morphologic changes during the menstrual cycle. Lu¨dicke. Combined oral contraceptive and human endometrium. Fertil Steril 2001.
shows a linear increase from day LH-1 to day LHϩ11/ϩ12.
intake of combined contraceptive steroids in the endome-
From day LHϩ6, glycoprotein-rich cytoplasmatic products
trium. Its glandular component is a sensible indicator for
are expelled into the glandular lumen, and the peak of
measuring the effect of contraceptive steroids. The progestin
intraglandular secretions coincides with the time of implan-
component in the COC inhibits proliferation of the endome-
tation of the free blastocyst (day 7 after ovulation) if fertil-
trium, which is in line with our findings in which signs of
ization takes place (10). The glandular epithelial cells are
characterized by rapid growth and increasing epithelial
pseudostratification, and epithelial height were found to be
height from LH-11 through LHϩ2, and the first reliable
clearly surpressed. When given at a dose of 30 g of EE, in
histologic alteration that is considered specific to ovulation is
combination with 3 mg of DRSP, atrophic appearance of the
basal vacuoles that start to appear in the glandular epithelium
endometrium was found in 44% of the women at six treat-
on day LH 0, and their number increases steadily up to day
ment cycles and in 63% of the women at 13 treatment cycles.
LHϩ4 (11). The preovulatory endometrium is characterized
These results are similar to what has been reported for other
by proliferation of glandular cells, stromal cells, and vascu-
COCs, such as the combination of 75 g of gestodene with
lar endothelial cells, and the maximum number of endome-
20 g of EE in which the rate of atrophy was about 50% at
trial cells engaged in DNA synthesis is seen between cycle
6 months of treatment (14). The reduction of the number of
day 8 and 10 and corresponds to maximal mitotic activity,
glands as seen in our study and others is a phenoma that
peak plasma estradiol levels, and maximum concentration of
cannot be observed in the menstrual cycle without COC
estrogen receptors (10). The size of the glands does not keep
medication and is apparently progestin-dose dependent. It
pace with this glandular growth, and the tall columnar epi-
has been shown that the release of 50 g of norethisterone
thelial cells finally pile up against each other with their
per 24 hours via a vaginal ring did not reduce the number of
nuclei at different levels, giving rise to pseudostratification
glands, whereas the release of 200 g/24 hours diminished
(12). Predecidualization starts to take place around day
significantly their number after 10 weeks of application (15).
LHϩ8 and is characterized by the conversion of stromal
In view of the fact that the induced endometrial changes are
cells into plump epithelial-like cells with enlarged nuclei and
limited to the functionalis layer of the endometrium but do
increased cytoplasm. The cells have metabolic functions
not affect the basalis layer, this effect is known to be revers-
related to pregnancy or, if conception has not occurred, to the
ible after withdrawal of the contraceptive steroids (8).
menstrual breakdown of the endometrium by phagocytotic
Although histology and morphometric measurements al-
digestion of extracellular collagen matrix (13).
low for the assessment of the impact of contraceptive ste-
Distinct histological changes can be observed during the
roids on the endometrium when compared with the normal
Lu¨dicke et al.
A combined oral contraceptive and human endometrium
cycle, give insights in the progestogenic potency of certain
Schellschmid, Schering AG, Clinical Development, Fertility Control and
progestins, and provide common grounds for the comparison
Hormone Therapy, Berlin, Germany. We also thank Christoph Gerlinger forthe statistical analysis, Schering AG, Biometry, Fertility Control and Hor-
of endometrial effects of different COCs, they do not predict
intermenstrual bleeding. Like earlier reports, the presentstudy did not reveal any correlation between the number ofdays of intermenstrual bleeding and the morphometric as-
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FERTILITY & STERILITY
OBSTETRICAL OVER THE COUNTER MEDICATION SHEET Avoidance of all medications that are not essential for health is a good principle to adhere to during pregnancy, especially the first 3-4 months. Nevertheless, certain common complaints or illnesses are unavoidable and justify the use of over the counter medications. Below are listed the medications which we feel are least likely to be harmful.
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