Medical Articles of Interest.
*These are abstracts of articles only. To understand
the findings more clearly it is advised that you seek out the entire
article, either on the internet or at a hospital library.
====================
BMJ 2002;324:447 ( 23 February, 2002 )
Low consumption of seafood in early pregnancy as
a risk factor for preterm delivery: prospective cohort study
Sjœrur Fr—i Olsen, associate professor, a Niels J¿rgen Secher, professor.
b a Maternal Nutrition Group, Danish Epidemiology Science Centre,
Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen S, Denmark,
b Perinatal Epidemiology Research Unit, Department of Obstetrics and
Gynaecology, Skejby University Hospital, DK-8200 Aarhus N, Denmark
Objective: To determine the relation between intake of seafood
in pregnancy and risk of preterm delivery and low birth weight.
Design: Prospective cohort study. Setting: Aarhus, Denmark.
Participants: 8729 pregnant women.
Main outcome measures: Preterm delivery and low birth weight.
Results: The occurrence of preterm delivery differed significantly
across four groups of seafood intake, falling progressively from 7.1%
in the group never consuming fish to 1.9% in the group consuming fish
as a hot meal and an open sandwich with fish at least once a week.
Adjusted odds for preterm delivery were increased by a factor of 3.6
(95% confidence interval 1.2 to 11.2) in the zero consumption group
compared with the highest consumption group. Analyses based on quantified
intakes indicated that the working range of the dose-response relation
is mainly from zero intake up to a daily intake of 15 g fish or 0.15
g n-3 fatty acids. Estimates of risk for low birth weight were similar
to those for preterm delivery. Conclusions: Low consumption of fish
was a strong risk factor for preterm delivery and low birth weight.
In women with zero or low intake of fish, small amounts of n-3 fatty
acids provided as fish or fish oil may confer protection against preterm
delivery and low birth weight.
===
What is already known on this topic
- Long chain n-3 fatty acids in amounts above 2 g a day may delay
spontaneous delivery and prevent recurrence of preterm delivery
- Large studies have not been carried out to determine to what extent
low consumption of n-3 fatty acids is a risk factor for preterm
delivery
- The dose-response relation has not been described What this study
adds
- Low consumption of fish seems to be a strong risk factor for
preterm delivery and low birth weight in Danish women
- This relation is strongest below an estimated daily intake of
0.15 g long chain n-3 fatty acids or 15 g fish
========================================================
The New England Journal of Medicine.
Volume 346:250-255 January 24, 2002 Number 4
Frequency of Uterine Contractions and the Risk
of Spontaneous Preterm Delivery
Jay D. Iams, M.D., Roger B. Newman, M.D., Elizabeth A. Thom, Ph.D.,
Robert L. Goldenberg, M.D., Eberhard Mueller-Heubach, M.D., Atef Moawad,
M.D., Baha M. Sibai, M.D., Steve N. Caritis, M.D., Menachem Miodovnik,
M.D., Richard H. Paul, M.D., Mitchell P. Dombrowski, M.D., Gary Thurnau,
M.D., Donald McNellis, M.D., for the National Institute of Child Health
and Human Development Network of MaternalÐFetal Medicine Units
ABSTRACT
Background The measurement of the frequency of uterine contractions
has not been useful for reducing the rate of preterm delivery in randomized
trials. Nonetheless, ambulatory monitoring of contractions continues
to be used in clinical practice.
Methods We assessed the frequency of uterine contractions
as a predictor of the risk of spontaneous preterm delivery before
35 weeks of gestation. We enrolled women with singleton pregnancies
between 22 and 24 weeks of gestation. The women used a contraction
monitor at home to record contraction frequency twice daily on 2 or
more days per week from enrollment to delivery or 37 weeks of gestation.
Results We obtained 34,908 hours of successful monitoring
recordings from 306 women. Although more contractions were recorded
from women who delivered before 35 weeks than from women who delivered
at 35 weeks or later, we could identify no threshold frequency that
effectively identified women who delivered preterm infants. The sensitivity
and positive predictive value of a maximal hourly frequency of contractions
of four or more between 4 p.m. and 3:59 a.m. were 9 percent and 25
percent, respectively, at 22 to 24 weeks and 28 percent and 23 percent
at 27 to 28 weeks. Other proposed screening tests, such as digital
and ultrasound evaluations of the cervix and assays for fetal fibronectin
in cervicovaginal secretions, also had low sensitivity and positive
predictive value for preterm labor.
Conclusions Although the likelihood of preterm delivery increases
with an increased frequency of uterine contractions, measurement of
this frequency is not clinically useful for predicting preterm delivery.
Source Information From the departments of obstetrics and
gynecology at Ohio State University, Columbus (J.D.I.); the Medical
University of South Carolina, Charleston (R.B.N.); the University
of Alabama, Birmingham (R.L.G.); Wake Forest University, Winston-Salem,
N.C. (E.M.-H.); the University of Chicago, Chicago (A.M.); the University
of Tennessee, Memphis (B.M.S.); the University of PittsburghÐMagee
Women's Hospital, Pittsburgh (S.N.C.); the University of Cincinnati,
Cincinnati (M.M.); the University of Southern California, Los Angeles
(R.H.P.); Wayne State University, Detroit (M.P.D.); the Biostatistics
Center at George Washington University, Washington, D.C. (E.A.T.);
and the National Institute of Child Health and Human Development,
Bethesda, Md. (D.M.). Gary Thurnau, M.D., University of Oklahoma,
Oklahoma City, was another author.
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BMJ 2001;323:1142-1143
( 17 November, 2001 )
Promoting normality in childbirth
Women and professionals should be encouraged to
consider vaginal birth positively
Researchers have shown much interest in possible explanations for
rising caesarean section rates.1 Consumer choice is seen as being
very influential. An often cited survey of London obstetricians found
that 31% would choose caesarean section as their preferred mode of
delivering babies. 2 3 However, there appear to be paradoxes within
this decision making process.4 Professionals choose abdominal delivery,
on the basis that it appears to be "easier, less painful and more
convenient," even though they consider it to be more expensive and
dangerous than a vaginal delivery.4 A subsequent study, with a wider
national base, found a more balanced attitude to normal birth, but
this has yet to be commented on in the national press.5 National data
in this area have been collected and the results of the national sentinel
audit of caesarean section were presented at the Royal College of
Obstetricians and Gynaecologists on 26 October 2001. Accurate comparative
figures on rates, indications, standards which can be audited, women's
views and clinicians' attitudes are available at www.rcog.org.uk/guidelines/nscs-audit.pdf
Although mothers' overall satisfaction with the experience of childbirth
is influenced by availability of choice and the sense of control,
adverse views undoubtedly correlate significantly with the degree
of intervention.6 There is evidence that obstetric interventions in
labour tend to lead from one to another. Women who have labour induced
need more help with pain relief, epidurals lead to more instrumental
births, and perineal trauma causes dyspareunia. Long term morbidity
after childbirth may be significant and is particularly related to
instrumental and caesarean delivery. Specific concerns relate to painful
intercourse and urinary and anal incontinence. Even elective caesarean
section does not avoid these particular complications, which may have
a closer relation to pregnancy itself than the mode of delivery.7
Doctors have a duty not to harm their patients, so must ensure that
any care does more good than harm, taking into account long term as
well as short term effects.
A focus on reducing caesarean section rates might be perceived as
somewhat negative. An alternative approach is to ask what can be done
about increasing the numbers of women who have a straightforward vaginal
birth, an intact perineum, and a healthy baby. We need to know which
systems of care are associated with optimal rates of normal birth.
Provided the baby and the mother are well and not compromised, there
is good evidence that avoiding an initial obstetric intervention and
providing women with one to one support increases the opportunity
that women will give birth spontaneously and avoid the increased risks
of surgery, perineal trauma, and separation from their baby associated
with more complex births.8
A further series of studies have examined the possibility of more
extended continuity of care.9 Disappointingly, although these studies
showed significant reductions in interventions such as epidural analgesia
and episiotomy, they did not increase rates of normal delivery.9 The
rates of intervention and variations in outcome are far greater between
studies than within them,9 suggesting that factors related to the
system have a greater influence on intervention rates than specific
midwifery input.
Epidural analgesia rates (69%) in traditional care at Queen Charlotte's
Hospital are higher than for those having one to one midwifery care
(56%) but contrast dramatically with a rate of 10.5% in the caseload
group in North Staffordshire.9 The audit commission commented on the
wide variations in intervention seen around the United Kingdom.10
Indeed, medicalisation of the environment could be the dominant effect
in the United Kingdom, over-riding potential benefits of continuity
of support and "knowing your midwife."
Avoiding defensive and medicalised environments may be the most
important next step. Initial evaluation of the Edgware birthing centre
has been very positive,11 and successful community focused approaches
have been reported from other countries. In the Swedish birthing centre
study normal delivery rates of nearly 90% were achieved.12
Further work urgently needs to be undertaken to extricate the essential
ingredients of success from midwifery units and regions that achieve
a high normal delivery rate with few interventions. Expectations and
attitudes of the community as well as those of pregnant women and
their carers are important. New approaches that examine choice and
control need to be examined, particularly in a climate where some
women are choosing interventions. Putting evidence into practice could
improve the outcome of labour for many thousands of women, and providing
there is a commitment to increasing the proportion of straightforward
vaginal births, change can be achieved without significant additional
funding.
It is important that all women and professionals should be encouraged
to consider vaginal birth positively. Women who have had a surgical
delivery should be encouraged to consider a trial of scar. Among professional
colleagues increasing interest and commitment to external cephalic
version for breech pregnancy13 and implementation of the NICE guidelines
on fetal monitoring (www.rcog.org.uk/guidelines/eb-guidelines.html)
are likely to be associated with a reduction in unnecessary intervention.
At the same time, further research is required on avoiding perineal
injury and on appropriate recognition and repair of injuries, with
a view to reducing the long term incidence of incontinence. (www.keele.ac.uk/depts/og).
Richard Johanson, consultant obstetrician and gynaecologist.
Mary Newburn, head of policy research, National Childbirth Trust.
Academic Department of Obstetrics & Gynaecology, North Staffordshire
Hospital Trust, Stoke on Trent, ST4 6QG
=====
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2. Le Fanu J. Too posh to push? Telegraph 2001; 29 May:18.
3. Al-Mufti R, McCarthy A, Fisk NM. Survey of obstetricians' personal
preference and discretionary practice. Eur J Obstet Gynecol Reprod
Biol 1997; 73: 1-4[Medline].
4. Johanson R, Lucking L. Evidence based medicine in obstetrics. Int
J Gynecol Obstet 2001; 72: 179-185[Medline].
5. Wright JB, Wright AL, Simpson NAB, Bryce FC. A survey of trainee
obstetricians preferences for childbirth. Eur J Obstet Gynecol Reprod
Biol 2001; 97: 23-25[Medline].
6. Anderson T. A survey of the influence of patient choice on the
increase in the caesarean section rate. Midwifery Digest 2001; 11:
368-370.
7. Clarkson J, Newton C, Bick D, Gyte, Kettle C, Newburn M, et al.
Achieving sustainable quality in maternity servicesusing audit of
incontinece and dyspareunia to identify shortfalls in meeting standards.
BMC Pregnancy Childbirth 2001; 1: 4.
8. Hodnett E. Caregiver support for women during childbirth (Cochrane
review). In: Cochrane Database Syst Rev. 2000;(2):CD000946.
9. The North Staffordshire Changing Childbirth Research Group. A randomised
study of midwifery caseload care and traditional 'shared care'. Midwifery
2000; 16: 295-302[Medline].
10. Middle C, Macfarlane A. Labour and delivery of 'normal' primiparous
women: analysis of routinely collected data. Br J Obstet Gynaecol
1995; 102: 970-977[Medline].
11. Rosser J. Birth centresthe key to modernising the maternity services.
Midwifery Digest 2001; 11: s22-6.
12. Waldenstrom U, Nilsson CA. Experience of childbirth in birth center
care: A randomized controlled study. Acta Obstet Gynecol Scand 1994;
73: 547-553[Medline].
13. Johanson RB. Breech birth: current obstetric thinking. Midwifery
Digest 2001; 11: s26-9.
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