common gynaecological disorders and their likely effect on fitness to fly
In 1784 Mm Elizabeth Thible ascended over Lyon, France in a
Montgolfier balloon probably aware of the generally held view of the day, and
in many respects a view still held today, that aviation was a male preserve. As the art and science of aviation evolved many of the
pioneering female aviation achievements have been met with scepticism, scorn,
and ridicule. Men have invented many reasons, often reflecting an ignorance
of female anatomy, physiology, and psychology to preclude women from a more
active participation in aviation. Even today there is much myth and male dominated
'reasoning' to prevent women from a more active role in military aviation. Thankfully
even this last bastion of male dominance in aviation is now crumbling as evidenced
by the NATO forces having in excess of 1000 female military pilots and permitting
some of them to fly active combat missions.
Despite being different to men in many respects there is no
intersex difference that makes women inherently less able to participate in
aviation pursuits than men. There are medical conditions peculiar to women that
may make them temporarily or permanently unfit to fly and as with men there are
features of some women that may make
them more or less suited to particular roles within the aviation industry. None
of these reasons however make the female of our species innately unsuitable
This essay introduces some of the physiological and pathological
conditions that are unique to women and discusses their potential effect on
'fitness to fly'. Fitness to fly, herein, refers to aircrew duties primarily
as a pilot but may also apply to navigators, flight engineers, and other occupations
peculiar to the military such as loadmasters and electronics operators. Fitness
to fly in this essay does not intend to include flying positions such as cabin
attendant, stewards, or passengers. In general terms a 'condition' is likely
to render a woman unfit to fly if there is a significant risk of:
Sudden incapacitation especially due to severe pain or the collapse
of an essential organ system;
Annoyance, disturbance, or distraction sufficient to interfere with
the safe conduct of flight responsibilities;
Restriction of free movement or the use of equipment based on normal
Dangerously altered mental function;
Inconvenience resulting in reduced effectiveness in flight.
Factors such as smaller average size (true), less strength
on average (true), less intelligence for technical matters (false), different
personality make-up (debatable), potential distraction of male colleagues (true),
reduced innate flying ability (false), and emotional liability (debatable) have
all been proposed at one time or another (by males I suspect) as reasons to
exclude women from aviation. While smaller size and less strength may make it
difficult for some women to perform some of the more physically demanding aircrew
duties this will gradually be overcome with time as ergonomic designs sympathetic
to women as well as men evolve. A number of studies have dismissed the myths
that women are inferior to men in aviation related cognitive and psychomotor
functions. While it can be argued that
women react to stress differently to men it could also be argued that in general
a woman's reaction is more productive than that of a man. While women may, in
general, have different personality traits to men there is no reason that this
should preclude them from aviation. Similarly many armed forces around the world
have exploded (often literally) the myth that the female psyche is unsuitable
for active combat roles. While no-one would argue that a woman, especially an
attractive woman, is a potential distraction for a male colleague it is bizarre
that this reason has been seriously touted as sufficient excuse to exclude women
from flight deck duties.
The medical and physiological conditions that will be discussed
are listed below. Between them this list would probably make up 99% of a routine
Absence or duplication of organs;
Fertility and Infertility
Menstruation and menstrual disorders:
Dysmenorrhoea, Amenorrhoea, Menorrhagia, etc.;
Dysfunctional Uterine Bleeding;
Pregnancy and it's Interruption:
Tumours of the trophoblast.
Pelvic Inflammatory Disease.
f Venereal Disease:
Syphilis; Herpes Simplex;
Genital Warts; HIV / AIDS.
Displacement of organs:
Uterine retroversion and
retroflexion; Uterine prolapse,
cystocoele, and rectocoele;
Ovarian, Cervical, Endometrial, Vaginal, Uterine Tube, and Vulval
Gynaecological hereditary disorders such as absence or duplication
of organs or an imperforate hymen are not common. A congenital duplication or
absence of parts of the female genital tract does not, in itself, render the
woman unsuitable for aviation. Associated anomalies of the renal tract may lead
to difficult to control urinary incontinence which may limit the depth of aviation
open to a woman (vice infra). An imperforate hymen is virtually always identified
and remedied prior to a woman attaining sufficient age to fly professionally,
or for pleasure. The presence of a gynaecological hereditary anomaly should
not, as a rule, preclude women from flying and each case should be individually
assessed to determine whether the condition is likely to 'interfere with the
safe exercise of licence and rating privileges' .
The fact that a woman is infertile,
in the absence of other problems, should have no effect what-so-ever on her
'fitness to fly'. Hormonal treatments for infertility may prompt review of a
woman's flying status if the medication results in mood or personality changes.
These rare cases should be reviewed on an individual basis.
The use of the oral contraceptive pill (OCP) has been associated
with an increase in the incidence of vascular thrombosis, thrombo-embolism,
cerebrovascular accident, hepatic adenomata, biliary disease, and hypertension.
The risk of the vascular complications is heightened if the woman taking the
pill is also a smoker. OCPs may also cause personality, mood, and weight changes
in certain susceptible individuals. Agents within an OCP may also interact with
other medications. While I do not have available any statistics on the incidence
of vascular complications amongst female aircrew I expect that they may be slightly
increased in those taking OCP medication but I also expect that this slight
increase would be overshadowed by the risk of smoking related problems. It is
my opinion that in the absence of adverse effects or reactions the use of OCP
medication should in no way stop a woman from flying. As with female mountaineers
I would, however, attempt to educate female pilots concerning the vascular risks
of oral contraception and strongly advise the cessation of smoking in any that
are so addicted. Women who have suffered adverse effects from OCPs should be
assessed on an individual basis. Although I can find no research data to support
me I find it difficult to imagine how any other form of contraception, in the
absence of complications, could possibly interfere with a woman's fitness to
fly (except perhaps the withdrawal method if practised during flight).
The normal, cyclical, menstrual period should, in no way, impair
a woman's fitness to fly. While ill informed 'back-bar' conversation amongst,
usually inebriated, male military aircrew occasionally broaches the potential
effects of high-G on women wearing a tampon or sanitary napkin there is no evidence
of any such unhygienic consequences of women flying during their period.
There is, however, potential for an abnormal or complicated
menstrual history to alter a woman's fitness to fly. While most cases of premenstrual
tension are mild the occasional woman finds this syndrome debilitating. Severe
premenstrual tension may be associated with aches and pains in the lower abdomen,
back, and breasts, headaches, weight gain, and personality or mood changes.
Any of these symptoms may make a woman unfit to fly during the premenstrual
period. Such severe symptoms, if unresponsive to treatment and if likely to
interfere with the safe conduct of flying tasks, should probably make a woman
either temporarily or permanently unfit to fly. A woman whose symptoms are well
defined and predictable and who is responsible and intelligent could justly
argue that she should not be permanently precluded from flying as she is able
to voluntarily ground herself during the premenstrual time period. I would seriously
consider supporting this logic in the case of a civil private licence but suggest
that the (often) lack of flexibility in commercial or military flying may make
her unfit for these duties.
Most women who suffer the mid-cycle pains of 'mittelshmerz'
find the problem of nuisance value only. Occasionally the pain can be more severe
leading to regular monthly bouts of incapacitation. I would apply similar logic
to the case of mittelshmerz as for premenstrual tension and assess each case
Similarly dysmenorrhoea, amenorrhoea, menorrhagia, and dysfunctional
uterine bleeding should all be assessed on their individual merits against the
guide 'likely to interfere with the safe exercise of licence and rating privileges'.
Dysmenorrhoea, or pain with menstruation, may be mild, moderate, or severe and
either responsive to treatment or not. Mild or moderate dysmenorrhoea, especially
if responsive to treatment need not interfere with a woman's flying status.
Severe dysmenorrhoea should be considered on an individual basis and may be
adequate cause for advising a woman as unfit to fly. Amenorrhoea, in itself,
is not due cause for disqualification although the commonest cause of amenorrhoea,
pregnancy, may well be (vide infra). The severity of menorrhagia will determine
whether an individual should be disqualified from flying. It is difficult to
imagine a woman wishing to fly while afflicted with severe menorrhagia. Similarly
dysfunctional uterine bleeding, diagnosed only after the exclusion of other
non-endocrine pathology will need to be assessed on individual merit.
Endometriosis may be a severe and incapacitating disorder causing
a woman to be unquestionably unfit to fly. This disqualification may need to
be reconsidered should the endometriosis respond well to hormone therapy or
ablative surgical procedures. This disease presents an element of uncertainty
in that mild endometriosis may progress to severe symptoms without warning and
treated cases may similarly erupt without notice. While each case needs to be
considered individually I would probably err on the side of conservatism, and
disqualification, with the unpredictable and potentially incapacitating endometriosis.
Adenomyosis uteri, with ectopic endometrial tissue with the muscular wall of
the uterus, should probably be afforded the same consideration as endometriosis.
While pregnancy is certainly not a gynaecological disorder
it is an event peculiar to women and carries with it the risk of impaired ability
to perform flying duties. The physiological changes of pregnancy that may interfere
with the safe operation of an aircraft include:
Nausea and vomiting of early pregnancy occur
in 30% of all pregnancies, and can cause dehydration and malnutrition;
Approximately 15% of embryos will abort
in the first trimester;
Cardiac output rises in early pregnancy,
accompanied by an increase in stroke volume, heart rate, and plasma
Haemoglobin, and haematocrit, begin to fall
between the third and fifth month and is lowest by the eight month of
Adequate diet and supplementary iron and
folic acid are necessary, but self medication and prescribed medication
should be avoided;
The incidence of venous varicosities is
three times higher in females than in males and venous thrombosis and
pulmonary embolism are among the most common serious vascular diseases
occurring during pregnancy;
As the uterus enlarges, it compresses and
obstructs the flow through the vena cava;
Progressive growth of the foetus, placenta,
uterus, and breasts, and the vasculature of these organs, leads to an
increased oxygen demand;
Increased blood volume and oxygen demands
produce a progressive increase in workload on both the heart and lungs;
Hormonal changes affect pulmonary function
by lowering the threshold of the respiratory centre to carbon dioxide,
thereby influencing the respiratory rate;
In order to overcome pressure on the
diaphragm, the increased effort of breathing and hyperventilation leads
to greater consciousness of breathing and possible greater cost in oxygen
The effects of hypoxia at increased altitude
further increases the ventilation required to provide for increasing
demands for oxygen in all tissues.
The first trimester of pregnancy exposes a woman to the risk
of early spontaneous abortion, emesis or hyperemesis gravidarum, and the cardiovascular
alterations mentioned above. Ectopic Pregnancy may also present during this
time period. Each of these conditions has potential to cause sudden incapacitation
in a female pilot and are of sufficient frequency to cause, in my opinion, a
woman in the first trimester of pregnancy to be unfit to fly.
Pregnancy's third trimester involves substantial somatic changes,
most noticeably abdominal enlargement. The third trimester also carries the
risks of premature labour and delivery as well as toxaemia of pregnancy. The
combination of these factors causes me to believe that a woman pregnant in her
third trimester is also unfit to fly.
The second trimester of pregnancy has a relatively low risk
of complication although the physiological changes outlined above continue.
Late spontaneous abortion is probably the most dramatic, albeit rare, complication
of the second trimester. While it can be well argued that a woman is fit to
fly during the second trimester I believe
that risks and the possible uncertainty of dates do not warrant rescinding her
disqualification during this middle two or three months of a pregnancy. I think
that a woman should be disqualified from flight while pregnant and that her
flying status should only be returned after a medical examination subsequent
to the conclusion, successful or otherwise, of her pregnancy.
A separate but related consideration is that of the incidence
of foetal damage or spontaneous abortion induced by the flight environment.
A first trimester foetus undergoes much of the organogenesis and differentiation
that is so sensitive to external noxious influences such as radiation and chemical
toxins. T here is the theoretical potential for the rigours of the flight environment
to cause an increased incidence of foetal malformations or spontaneous abortions
in pregnant female aircrew. The limited research available tends to consider
air-hostesses rather than female pilots and does not seem to support the hypothesis
of an increase in abnormal pregnancy outcomes
Air hostesses do suffer an increase in spontaneous abortion when compared to
other women but not when compared to other working women. There is an increased
incidence of past spontaneous abortion amongst pregnant air-hostesses
but this may be due to a selection bias where a previous successful pregnancy
selects an individual out of the test population.
To have a tumour of the trophoblast a woman would need to be
pregnant and hence I would deem her unfit for flying duties. Malignant sequelae
to trophoblastic tumours will be considered with other carcinomas later.
Gynaecological infections such as bartholinitis, vaginitis,
cervicitis, and pelvic inflammatory disease need not necessarily exclude a woman
from flying. The discomfort associated with each of the above may cause temporary
self suspension from flight or similar advice from a DAME should he/she be consulted.
Once adequately treated none of these conditions should disqualify a woman from
flight duties. Severe, uncontrolled pelvic inflammatory disease may cause sufficient
incapacity to prompt a long term or permanent disqualification from flying on
Women suffering venereal diseases such as gonorrhoea,
urethritis, syphilis, herpes simplex, genital warts, and HIV / AIDS should all
be assessed for fitness to fly on their individual merit and the likely history
of the disease in question. It is unlikely that gonorrhoea, nonspecific urethritis
or primary syphilis would necessarily ground a woman. The now very rare secondary
or later sequelae of spirochaetal infection may be sufficient ground for disqualification
due to the incidence of neurological and other systemic complications. Unless
they cause great discomfort genital warts or genital herpes infections are an
unlikely cause for disqualification. On the other hand I feel that the possibility
of unpredictable neurological AIDS should preclude all HIV positive individuals,
male or female, from aircrew status. I believe this should apply to all aircrew,
not just pilots and navigators. Any aviator that presents with any venereal
disease should also have their HIV status determined
Gynaecological organ displacement problems such as uterine
retroversion and retroflexion, uterine prolapse, cystocoele, and retrocoele
should be assessed on their individual merit. Uterine flexion or version should
have no influence on a woman's fitness to fly. Second and third degree uterine
prolapse as well as major cystocoeles or rectocoeles may be aufficient cause
for temporary self suspension from flying while the problem is rectified. High-G
military or civil acrobatic flight raises interesting questions with respect
to conservatively treated (pessary) uterine prolapse. I suppose that it is theoretically
possible that increased +Gz loading could cause prolapse of a poorly suspended
previously prolapsed uterus. This is an extremely unlikely event and although
of likely nuisance value is unlikely to be incapacitating. The fitness to fly
of women with conservatively managed uterine prolapse should probably be considered
on their individual merits.
I recall 'back-bar' discussion along these lines over the last
few years. It was seriously believed by some male military aviators that the
high-G of tactical manoeuvres would cause a normal uterus to prolapse. This
caused great mirth as the discussion moved to the design of a suitable G-suit
extension to prevent this 'G Induced Prolapse'.
While not an absolute contraindication to flying the problems
associated with stress incontinence may prove to be significant enough to cause
disqualification. As with the gynaecological organ displacement disorders stress
incontinence is very rarely a problem of healthy young women and so is unlikely
to present at an initial aircrew student medical examination. Uncontrolled stress
incontinence may cause sufficient discomfort, embarrassment, and hygiene problems
to prompt disqualification. It seems unlikely that a woman with this degree
of stress incontinence would want to continue flying anyway.
Benign gynaecological tumours such as uterine lieomyomata (fibroids),
or adenomatous polyps would not generally preclude a woman from being fit to
fly. Large or complicated polyps or fibroids may temporarily disqualify a woman
until adequately treated.
The case of malignancy is not so clear cut. On the one hand
ovarian, cervical, endometrial, vaginal, uterine tube, and vulval carcinomata
as well as the malignant sequelae to a hydatidiform mole all have the potential
for dissemination and relapse after treatment. Dissemination or relapse of a
malignancy may cause sudden unexpected incapacitation especially if the metastatic
deposit is located within the (.NS or undergoes rapid haemorrhagic degeneration.
On the other hand it is possible to 'cure' most malignancies to a degree that
relapse or complication is very unlikely. Similarly there are other malignancies,
such as squamous cell carcinoma of the skin, that only disseminate in extremely
rare cases. While I am tempted to recommend that any malignancy except skin
SCC should disqualify a person from flying status it is probably fairer to recommend
that each case be considered on its merit. Factors such as histological typing,
grade and stage, mode of treatment, time since treatment, and general health
would all need to be very favourable before I would endorse a patient with a
malignant disease as fit to fly.
As discussed above the majority of gynaecological conditions
would not necessarily cause me to disqualify a patient from active aircrew status
on medical grounds. With the exception of pregnancy and HIV infection I feel
that each gynaecological disorder should be considered on its individual merit.
Each case should be assessed for the likelihood of it causing sudden incapacitation,
dangerously altered mental function, annoyance, disturbance, or distraction
sufficient to interfere with the safe conduct of flight responsibilities, restriction
of free movement or the use of equipment based on normal ergonomic design, or
any inconvenience resulting in reduced effectiveness in flight. The only conditions
to which I would apply a 'blanket cover' of disqualification are pregnancy and
HIV infection while I would require a lot of positive prognostic indicators
to award a patient with a malignancy or endometriosis a medical 'fit to fly'