Practical implications.
In our society, since the advent of medicalized
prenatal care, the emotional state of pregnant women is highly
influenced by health professionals, particularly doctors. We can
therefore assume that, in an ideal world, the main preoccupation
of doctors and other health professionals involved in prenatal
care should be to protect the emotional state of pregnant women.
However everybody heard of countless women who were unsettled
and apprehensive after an antenatal visit. It is obvious that
the dominant style of antenatal care – constantly focusing
on potential problems – has an inherent ‘nocebo effect’.
The nocebo effect is a negative effect on the emotional state
of pregnant women and indirectly of their families. It occurs
whenever a health professional makes more harm than good by interfering
with the imagination, the fantasy life or the beliefs of a patient
or a pregnant woman.(1,2,3)
It should not take so long for an adaptable health professional
to shift towards a positive attitude and to overcome the current
situation. Modern pregnant women cannot be blissful. All of them
have at least one reason to be worried: "your blood pressure
is too high or too low", "your weight is increasing
too quickly or too slowly", "you are anaemic",
"you might hemorrhage because your platelet count is low",
"you have a gestational diabetes", "your baby is
too small or too big", “there is too much liquid around
the baby”, “there is a lack of liquid”, "the
placenta is low", "you are 18 and teen-age pregnancy
is associated with specific risks", "you are 39 and
pregnancy at an old age is associated with specific risks",
"your baby has not yet turned head first", “the
baby’s back is on the right side, which makes the birth
difficult”, "according to the blood sample you are
at risk of having a Down's syndrome baby", "you did
not take folic acid at the right time and we must consider the
risk of spina bifida", "you are not immunised against
rubella", "you are Rh negative", "if you have
not given birth on Wednesday, we must consider an induction",
etc. Is it still possible to be a "normal" woman?
In the same ideal world, the expectant mother should be guided
by a primary practical question: “What can the doctor do
for me and my baby?” If we consider the usual case of a
woman who knows that she is pregnant, who knows roughly when her
baby was conceived, who has no reason for complaint, the humble
response should be: “Not a lot, apart from detecting a gross
abnormality and offering an abortion”.
Should we reconsider the concept
of routine medicalized prenatal care?
In many countries about ten prenatal visits
is routine. In other words, most women have ten opportunities
to hear about potential problems. At each visit a battery of tests
is offered. These traditional patterns of medical care are based
on the belief that more antenatal visits mean better outcomes.
They are not based on scientific data. That is why the very concept
of routine medicalized care and the number of visits must be re-examined.
British studies failed to find any association between beginning
prenatal care late and adverse outcomes for the mother or the
baby (4) or between the number of visits and the onset of the
disease eclampsia (5). This casts doubts on the efficacy of such
protocols. Within the British National Health Service, the number
of visits is not as strongly associated with socio-economic status
as it is in the USA. This makes the results of the British studies
comparatively easier to interpret than those of the American studies
(6,7).
However, it is worth analyzing a 2002 report by the ‘Center
for Disease Control and Prevention’ in the USA. It appears
that women who were born outside the USA are more likely than
their racial and ethnic counterparts born in the USA to begin
prenatal care late or to have no prenatal care at all. ‘In
spite of that’ (or perhaps ‘because of that’?)
state born women are more likely than their counterparts born
outside the United States to give birth preterm or to give birth
to a low weight baby. It is also fruitful to analyze trials comparing
different schedules of antenatal visits. One was conducted in
California, in a Kaiser Permanente Medical Center (8). A second
trial, in South East London, involved 2794 women (9). A third
one, by the World Health Organization, involved 53 centres in
Thailand, Cuba, Saudi Arabia and Argentina (10). None of these
trials demonstrated any benefits of conventional schedules compared
with reduced visit schedules.
One may also wonder if women who have a great number of antenatal
visits give birth more easily than those with none. A study on
the effect of cocaine use on the progress of labour unexpectedly
suggested the opposite (11). The researchers took into account
that one-third of cocaine users had no prenatal care. It was therefore
essential to determine the average dilation at admission among
nonusers of cocaine who had no prenatal care. It appeared that
the mean dilation at admission in this group was more than 5 cm.
Should we reconsider the content
of prenatal visit?
Not long ago the main reason for the first antenatal
visit was to establish the diagnosis of pregnancy and to determine
the due date. Since reliable pregnancy tests can now be bought
over-the-counter, most women have their pregnancy confirmed before
visiting a health professional and have a reliable date of conception.
Knowing that a pregnancy lasts about nine months, most women can
calculate the most probable time for the birth of their baby.
One can therefore claim that the primary reason for an early antenatal
visit has disappeared.
Routine ultrasound scanning in pregnancy became the symbol of
modern prenatal care. It is also its most expensive component.
A series of studies compared the effects on birth outcomes of
routine ultrasound screening versus the selective use of the scans.
An American trial involved more than 15,000 pregnant women (12).
The last sentence of the article is unequivocal: “The findings
of this study clearly indicate that ultrasound screening does
not improve perinatal outcome in current US practice”. Around
the same time, an article in British Medical Journal (13) assembled
data from four other comparable trials. The authors concluded:
“Routine ultrasound scanning does not improve the outcome
of pregnancy in terms of an increased number of live births or
of reduced perinatal morbidity. Routine ultrasound scanning may
be effective and useful as a screening for malformation. Its use
for this purpose, however, should be made explicit and take into
account the risk of false positive diagnosis in addition to ethical
issues”.
It is possible that, in the future, a new generation of studies
(in the framework of primal health research) will cast doubts
on the absolute safety of repeated exposure to ultrasound during
fetal life. One of the effects of the selective use is to reduce
dramatically the number of scans, particularly in the vulnerable
phase of early pregnancy.
Even in a high risk population of pregnant women, ultrasound scans
are not as useful as commonly believed. Evidence from several
trials suggests that sonographic identification of fetal growth
retardation does not improve outcome despite increased medical
surveillance (14,15). In diabetic pregnancies it has been demonstrated
that ultrasound measurements are not more accurate than clinical
examination to identify high birth weight babies (16). This led
to the memorable title of an editorial of British Journal of Obstetrics
and Gynaecology: ‘Guess the weight of the baby’.
In many countries, the amount of red blood cells pigment (haemoglobin
concentration) is routinely measured in pregnancy. There is a
widespread belief that this test can effectively detect anaemia
and iron deficiency. In fact, this test cannot diagnose iron deficiency
because the blood volume of pregnant women is supposed to increase
dramatically, so the haemoglobin concentration indicates first
the degree of blood dilution, an effect of placental activity.
A large British study, involving more than 150,000 pregnancies
(17), found that the highest average birth weight was in the group
of women who had a haemoglobin concentration between 8.5 and 9.5.
Furthermore, when the haemoglobin concentration fails to fall
below 10.5 there is an increased risk of low birth weight, preterm
birth and pre-eclampsia. The regrettable consequence of routine
evaluation of haemoglobin concentration is that, all over the
world, millions of pregnant women are wrongly told that they are
anaemic and are given iron supplements. There is a tendency both
to overlook the side effects of iron (constipation, diarrhea,
heartburn, etc.) and to forget that iron inhibits the absorption
of such an important growth factor as zinc (18). Furthermore,
iron is an oxidative substance that can exacerbate the production
of free radicals and might even increase the risk of pre-eclampsia
(19).
Another routine screening practiced in certain countries is for
so-called gestational diabetes. This is the reason for using the
glucose tolerance test. If the glycaemia (amount of glucose in
the blood) is considered too high after absorption of sugar, the
test is positive. This diagnosis is useless because it merely
leads to simple recommendations that should be given to all pregnant
women. These are recommendations regarding lifestyle, particularly
dietary habits and exercise. Dietary recommendations must focus
on the quality of carbohydrates. The most useful way to rank foods
is according to their ‘glycaemic index’. Pregnant
women must be encouraged to prefer, as far as possible, low glycaemic
index foods. A food has a high index when its absorption is followed
by a fast and significant increase of the blood glucose level.
In practice this means, for example, that pregnant women must
avoid the countless soft drinks that are widely available today,
and that they must also avoid adding too much sugar or honey in
their tea or coffee. Glycaemic index tables of hundreds of foods
have been published in authoritative medical journals. These tables
must be looked at carefully, because the data they provide are
often surprising for those who are still influenced by old classifications
contrasting simple sugars and complex carbohydrates. Such classifications
were taking account the mere chemical formula.
From such tables we can learn in particular that breakfast cereals
based on oats and barley have a low index. Wholemeal bread and
pasta also are low-index foods. Potatoes and pizzas, on the hand,
have a high index and should therefore be consumed with moderation.
Comparing glucose and fructose (the sugar of fruit) is a way to
realize the lack of correlation between chemical formula and glycaemic
index. Both are small molecules with six atoms of carbon and have
pretty similar chemical formulas. Yet the index of glucose is
100…versus 23 for fructose. This means that pregnant women
must be encouraged to eat fruit and vegetables.
The benefits of a regular physical activity in pregnancy should
also be a routine discussion during prenatal visits, whatever
the results of sophisticated tests. A huge Canadian study demonstrated
that the only effect of routine glucose tolerance screening was
to inform about three per cent of pregnant women that they have
gestational diabetes (20). The diagnosis did not change the birth
outcomes.
Even the routine measurement of blood pressure in pregnancy may
be reconsidered. Its original purpose was to detect the preliminary
signs of pre-eclampsia, particularly at the end of a first pregnancy.
But increased blood pressure, without any protein in the urine,
is associated with good birth outcomes (21,22,23,24). The prerequisite,
to diagnose pre-eclampsia, is the presence of more than 300 mg
of protein in the urine per 24 hours. Finally, it is more useful
to rely on the repeated use of the special strips for ‘urinalysis’
one can buy in any pharmacy. Measuring the blood pressure is thus
not essential.
After challenging the very principle of routine medicalized care
in pregnancy and after evaluating the content of antenatal visits,
we can explore the issue from a third perspective. We can wonder
what the doctor can do after the conception of a baby, in order
to influence outcomes. Since prematurity is a major preoccupation,
let us focus on what medical care can offer in order to reduce
the incidence of preterm births. Recently, considerable research
focused on the potential for antibiotic prophylaxis. A large trial
involving more than 6000 women did not support the use of antibiotics
(25). Furthermore, the treatment of vaginal infection in early
pregnancy does not decrease the incidence of preterm delivery
(26). Surgical closure of the cervix (‘cerclage’)
has been widely used in order to reduce the risk of premature
birth especially in cases of a short and ‘incompetent’
cervix. In fact, the data conflict about the value of this technique,
which reportedly doubles the risk of fever after the birth of
the baby (27). Medical interventions also do not reduce the risk
of having a small-for-date baby. Even bed rest restrictions are
useless and even harmful.
The future
We should not conclude that there is no need
at all for medical visits in pregnancy: we cannot make a comprehensive
list of all the reasons why women might need the advice or the
help of a qualified health professional before giving birth. It
is the word ‘routine’ that should be discarded. It
is easy to explain why the current habits are a waste of time
and money; it is also easy to explain why they are potentially
dangerous. It is dangerous to misinterpret the results of a routine
test and to tell a healthy pregnant woman that she is anaemic
and that she needs iron supplements. It is dangerous to present
an isolated increased blood pressure measurement as bad news.
It is dangerous to tell a pregnant woman that she has a ‘gestational
diabetes’.
The fall of routine medicalized antenatal care should go along
with a rediscovery of the basic needs of pregnant women. We cannot
dissociate the physiological changes in pregnancy and birth physiology.
It is as if the birth process was physiologically prepared long
in advance. We must give a great importance to a study demonstrating
that, during pregnancy, there is a significant reduction of the
blood flow in the large arteries going to the brain.(28) Is the
pregnant woman preparing herself to reduce the activity of her
neocortex in order to make the birth possible?
One of the needs of pregnant women is to socialize and share their
experiences. It is easy to create occasions for that: swimming,
yoga, prenatal exercise sessions… I well remember the atmosphere
of happiness that accumulated during singing encounters in the
maternity unit at the Pithiviers Hospital in France. These singing
sessions probably had more positive effects on the development
of babies in the womb and also on the birth process than a series
of ultrasound scans.(29)
References:
1 - Odent M. The Nocebo effect in prenatal care. Primal Heath
Research Newsletter 1994; 2 (2).
2 - Odent M. Back to the Nocebo effect. Primal Heath Research
Newsletter 1995; 5 (4).
3 - Odent M. Antenatal scare. Primal Heath Research Newsletter
2000; 7 (4).
4 – Thomas P, Golding J, Peters TJ. Delayed antenatal care:
does it affect pregnancy outcome? Soc Sci Med 1991; 32: 715-23.
5 – Douglas KA, Redman CW. Eclampsia in the United Kingdom.
BMJ 1994; 309: 1395-400.
6 – Vintzileos AM, Ananth CV, et al. The impact of prenatal
care in the United States on preterm births in the presence or
absence of antenatal high-risk conditions. Am J Obstet Gynecol
2002; 187: 1254-7.
7 – Vintzileos AM, Ananth CV, et al. The impact of prenatal
care on postneonatal deaths in the presence or absence of antenatal
high-risk conditions. Am J Obstet Gynecol 2002; 187: 1258-62.
8 – Binstock MA, Wolde-Tsadik G. Alternative prenatal care:
impact of reduced visit frequency, focused visits and continuity
of care. J Reprod Med 1995; 40: 507-12.
9 – Sikorski J, Wilson J, et al. A randomised controlled
trial comparing two schedules of antenatal visits: the antenatal
project. BMJ 1996; 312: 546-53.
10 – Villar J, Baaqueel H, et al. WHO antenatal care randomized
trial for the evaluation of a new model of routine antenatal care.
Lancet 2001; 357: 1551-64.
11 – Wehbeh H, Matthews RP, et al. The effect of recent
cocaine use on the progress of labor. Am J Obstet Gynecol 1995;
172: 1014-8.
12 – Ewigman BG, Crane JP, et al. Effect of prenatal ultrasound
screening on perinatal outcome. N Engl J Med 1993; 329: 821-7
13 – Bucher HC, Schmidt J G. Does routine ultrasound scanning
improve outcome in pregnancy? Meta-analysis of various outcome
measures. BMJ 1993; 307: 13-7.
14 – Larson T, Falck Larson J, et al. Detection of small-for-gestational-age
fetuses by ultrasound screening in a high risk population: a randomized
controlled study. Br J Obstet Gynaecol 1992; 99: 469-74.
15 – Secher NJ, Kern Hansen P, et al. A randomized study
of fetal abdominal diameter and fetal weight estimation for detection
of light-for-gestation infants in low-risk pregnancy. Br J Obstet
Gynaecol 1987; 94: 105-9.
16 – Johnstone FD, Prescott RJ, et al. Clinical and ultrasound
prediction of macrosomia in diabetic pregnancy. Br J Obstet Gynaecol
1996; 103: 747-54.
17 - Steer P, Alam MA, Wadsworth J, Welch A. Relation between
maternal haemoglobin concentration and birth weight in different
ethnic groups. BMJ 1995; 310:489-91.
18 - Valberg LS. Effects of iron, tin, and copper on zinc absorption
in humans. Am J Clin Nutr 1984; 40:536-41.
19 – Rayman MP, Barlis J, et al. Abnormal iron parameters
in the pregnancy syndrome preeclampsia. Am J Obstet Gynecol 2002;
187 (2): 412-8.
20 - Wen SW, Liu S, Kramer MS, et al. Impact of prenatal glucose
screening on the diagnosis of gestational diabetes and on pregnancy
outcomes. Am J Epidemiol 2000; 152(11): 1009-14.
21 - Symonds EM. Aetiology of pre-eclampsia: a review. J R Soc
Med 1980; 73: 871-75.
22 - Naeye EM. Maternal blood pressure and fetal growth. Am J
Obstet Gynecol 1981; 141: 780-87.
23 - Kilpatrick S. Unlike pre-eclampsia, gestational hypertension
is not associated with increased neonatal and maternal morbidity
except abruptio. SPO abstracts. Am J Obstet Gynecol 1995; 419:
376.
24 - Curtis S, et al. Pregnancy effects of non-proteinuric gestational
hypertension. SPO Abstracts. Am J Obst Gynecol 1995; 418: 376.
25 – Kenyon SL, Taylor DJ, Tarnow-Mordi W. Broad spectrum
antibiotics for spontaneous preterm labour: the ORACLE II randomized
trial. Lancet 2001; 357: 989-94.
26 – Guise JM, Mahon SM, et al. Screening for bacterial
vaginosis in pregnancy. Am J Prev Med 2001; 20 (suppl 3): 62-72.
27 – MRC/RCOG Working party on cervical cerclage. Final
report of the Medical Research Council/Royal College of Obstetricians
and Gynaecologists multicentre randomized trial of cervical cerclage.
BJOG 1993; 100: 516-23.
28 – Zeeman GZ, Hatab M, Twickler DM. Maternal cerebral
blood flow changes in pregnancy. Am J Obstet Gynecol 2003; 189(4):
29 – Odent M. Birth Reborn. Pantheon (NY). 1984.
(Click here to go back to the
top of the page)
