Maternal age and fetal loss: population based register linkage studyBMJ 2000; 320 doi: https://doi.org/10.1136/bmj.320.7251.1708 (Published 24 June 2000) Cite this as: BMJ 2000;320:1708
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Editor - The latest of three Danish reports about reproductive history informs readers, "Fetal loss is
high in women in their late 30s or older, irrespective of reproductive history. This should be taken into consideration in pregnancy planning and counselling."(1) Consider a woman ("Alice") whose first pregnancy occurs at age 30. According to "Melbye, Olsen" et al, "Alice", if pressured by others to have an induced abortion of her pregnancy, should be warned that if she does so, she will increase her risk of never having a birth. Will "Alice" be told by the abortion clinic that her best chance for a full-term birth is for 30 year-old "Alice" to carry her current pregnancy to term? No, "Alice" will not be so told, since no abortion clinic consent form mentions such a risk. Even if "Alice" has a future birth, a previous induced abortion about doubles her risk that that birth will be very preterm (less than 34 weeks' gestation) according to another study of Danish women (RR=1.99 95% CI=1.64-2.43).(3) If Alice has two "evacuation" type abortions, she elevates her risk of preterm birth by 1155% (95% CI=5.14- 30.64).(3) There are at least seven other reports that found increased prematurity risk from previous induced abortion.(4-10)
By not informing prospective patients of health risks associated with induced abortion, abortion doctors are violating their legal duty to protect health, not needlessly endanger it.
Is there any serious health risk for the mother of a preterm infant. According to a third study of Danish women, "Melbye" et al inform us that if the gestation of a newborn is under 32 weeks, the mom has doubled her breast cancer risk (vs a full-term birth); RR=2.08, 95% CI=1.20-3.60 for gestation of 29-31 weeks.(2)
Let's assure that women of reproductive age are fully informed about health risks of medical treatments to them and their future children.
Reduce Preterm Risk Coalition, 3456 Dunbar St. (146), Vancouver, Canada V6S 2C2
1 Andersen A-M N, Wohlfahrt J, Christens P, Olsen J, Melbye M. Maternal age and fetal loss: population based register linkage study. BMJ 2000;320:1708-1712
2 Melbye M, Wohlfahrt J, Andersen A-M N, Westergaard T, Andersen PK. Preterm delivery and risk of Breast Cancer. British J Cancer 1999 80(3/4):609-613
3 Zhou W, Sorenson HT, Olsen H. Induced Abortion and Subsequent Pregnancy Duration. Obstetrics & Gynecology 1999;94:948-953
4 Pickering RM, Forbes J. Risk of preterm delivery and small-for-gestational age infants following abortion: a population study. British J Obstetrics and Gynecology 1985;92:1106-1112
5 Michielutte R, Ernest JM, Moore ML, Meis PJ, Sharp PC, Wells HB, Buescher PA. A Comparison of Risk Assessment Models for Term and Preterm Low Birthweight. Preventive Medicine 1992;21:98-109
6 Berkowitz GS. An Epidemiologic Study of Preterm Delivery. American J Epidemiology 1981;113:81-2
7 Lieberman E, Ryan KJ, Monson RR, Schoenbaum SC. Risk Factors Accounting For Racial Differences in the rate of premature birth. NEJM 1987;317:743-748
8 Lang JM, Lieberman E, Cohen A. A Comparison of Risk Factors for Preterm Labor and Term Small-for-Gestational-Age Birth. Epidemiology 996;7:369-376
9 Mueller-Heubach E, Guzick DS. Evaluation of risk scoring in a preterm birth prevention study of indigent patients. Am J Obstetrics & Gyn 1989;160:829-837
10 Shiono PH, Lebanoff MA. Ethnic Differences and Very Preterm Delivery. Am J Public Health 1986;76:1317-1321
Competing interests: No competing interests
Terminology for early pregnancy loss.
Two years ago we wrote that the language culture of early pregnancy
loss cannot be changed without a change in the medical literature. We
advised that editors of medical journals should ensure that the word
abortion is avoided when referring to spontaneous pregnancy 1. This
miscarriage terminology is recommended by the Royal College of
Obstetricians and Gynaecologists and is increasing used in the medical
literature 2. The editorial on the subject of risks of having children in
later life3 conformed to the recommended terminology but unfortunately the
term spontaneous abortion was used throughout the article on maternal age
and fetal loss4. No doubt the Danish authors were not aware of the English
language recommendation which is why we advised responsibility be taken by
journal editors. The article used spontaneous abortion no less than 55
times. If nothing more, adoption of the word miscarriage would have
shortened the article by 55 words.
David J R Hutchon
Consultant Obstetrician and Gynaecologist.
1. Hutchon D J R, Cooper S. Terminology for early pregnancy loss
must be changed. BMJ 1998;317:1081
2. Jurkovic D, Ross J A, Nicolaides K H. Expectant management of
missed miscarriage. Br J Obstet Gynaecol 1998:105:670-671
3. Stein Z, Susser M. The risk of having children in later life. BMJ
4. Anderson A N, Wohlfahrt J, Christens P, Olsen J, Melbye M.
Maternal age and fetal loss: population based register linkage study. BMJ
Competing interests: No competing interests
The stated objective of Anne-Marie Nybo Andersen and colleagues' study of
fetal loss was to measure the age related risk of fetal loss "taking into
account a woman's reproductive history" (1). To this end they stratified
according to parity and previous spontaneous abortions but inexplicably
omitted stratification by induced abortions. Their only reported use of
their very complete data on induced abortions was to deduct from the count
of fetal loss any miscarriages that occurred prior to an intended
Even within the medical community, elective abortion is a contentious
issue. The medical literature is filled with conflicting findings
regarding the effects of induced abortion on subsequent pregnancies. Some
investigators have found statistical associations between induced abortion
and subsequent miscarriage and ectopic pregnancies. (2,3,4,5). Others
have reported that there is no significant association between abortion
and either miscarriage or ectopic pregnancies (6,7,8,9). Notably,
colleagues of Nybo Andersen at the Danish Epidemiology Science Centre,
using much of the same data, have recently reported a strong association
between induced abortion and subsequent pre- and post-term deliveries
(10,11). This finding would appear to add to concerns that induced
abortion may contribute to subsequent fetal loss.
In this particular attempt to measure the age related risk, a
stratification by induced abortion is especially important since older
women are more likely to have a history of multiple induced abortions.
Another confounding factor, as noted by Mats Reimer M.D. in his
electronic response to this article, is that Danish women have high
smoking rates and smoking is associated with higher fetal loss. That
association is complicated even further by the fact that induced abortion
itself is strongly associated with higher rates of smoking.(3,12,13) This
may be related to emotional reactions to abortion (anxiety or depression,
perhaps) which is "medicated" through smoking. Similarly, several studies
link abortion to increased levels of subsequent drug and/or alcohol abuse
(also forms of "self-medication") which may also contribute to fetal loss
In addition, clinical experience and surveys of women participating
in post-abortion counseling programs report that some women report
becoming promiscuous after an abortion, a reaction they often attribute to
lower self-esteem (19,20,21). If this behavioral impact is to any degree
widespread, this psychological and behavioral reaction to abortion may
increase exposure to venereal diseases and multiple induced abortions,
either of which may contribute to pregnancy loss.
Substance abuse, smoking, venereal disease may all be interrelated
via abortion (and any number of additional factors). These
interrelationships may explain why abortion as a risk factor for fetal
loss can be reduced when statistical weights are applied to control for
smoking, alcohol, drugs, or venereal disease (8). The daunting task of
properly sorting out these confounding interactions, incidental
associations, and hidden proxy effects has barely begun.
Therefore, researchers working with large registry based data sets
should always stratify separately for induced abortion. The failure to do
so only postpones clarification of important research issues. In this
particular study, the failure to stratify on induced abortion is even more
egregious since stratification was done for spontaneous abortion. Given
the sensitive nature of induced abortion, the failure to stratify on
induced abortion may inadvertently arouse the unwarranted suspicion that
researchers are suppressing data, for ideological reasons, about either
the potential risks, benefits, or benign nature of elective abortion.
David C. Reardon, Ph.D.
(1) Andersen AM, Wohlfahrt J, Christens P, Olsen J, Melbye M. Maternal age
and fetal loss: population based register linkage study. BMJ 2000 Jun
(2) Infante-Rivard C, Gauthier R. Induced abortion as a risk factor for
subsequent fetal loss. Epidemiology 1996 Sep;7(5):540-2.
(3) Levin AA, Schoenbaum SC, Monson RR, Stubblefield PG, Ryan KJ.
Association of induced abortion with subsequent pregnancy loss. JAMA 1980
(4) Parazzini F, Ferraroni M, Tozzi L, Ricci E, Mezzopane R, La Vecchia C.
Induced abortions and risk of ectopic pregnancy. Hum Reprod. 1995
(5) Tharaux-Deneux C, Bouyer J, Job-Spira N, Coste J, Spira A. Risk of
ectopic pregnancy and previous induced abortion. Am J Public Health 1998
(6) Parazzini F, Chatenoud L, Tozzi L, Di Cintio E, Benzi G, Fedele L.
Induced abortion in the first trimester of pregnancy and risk of
miscarriage. Br J Obstet Gynaecol. 1998 Apr;105(4):418-21.
(7) Bracken MB, Bryce-Buchanan C, Srisuphan W, Holford TR, Silten R. Risk
of late first and second trimester miscarriage after induced abortion. Am
J Perinatol 1986 Apr;3(2):84-91.
(8) Skjeldestad FE, Atrash HK Evaluation of induced abortion as a risk
factor for ectopic pregnancy. A case-control study. Acta Obstet Gynecol
Scand 1997; Feb;76(2):151-8
(9) Atrash HK, Strauss LT, Kendrick JS, Skjeldestad FE, Ahn YW. The
relation between induced abortion and ectopic pregnancy. Obstet Gynecol
(10) Zhou W, Sorensen HT, Olsen J. Induced abortion and subsequent
pregnancy duration. Obstet Gynecol 1999 Dec;94(6):948-53.
(11) Zhou W, Sorensen HT, Olsen J. Induced abortion and low birthweight in
the following pregnancy. Int J Epidemiol 2000 Feb;29(1):100-6.
(12) Obel, EB. Pregnancy complications following legally induced abortion:
An analysis of the population with special reference to prematurity.
Danish Medical Bulletin 1979; 26:192-199.
(13) Harlap S, Davies AM. Characteristics of pregnant women reporting
previously induced abortions, Bull World Health Organ. 1975; 52(2):149-54.
(14) Morrissey, E. & Schuckit, M., "Stressful Life Events and Alcohol
Problems among Women Seen at a Detoxication Center" J. Stud. Alcohol
(15) Reardon DC, Ney PG. Abortion and subsequent substance abuse. Am J
Drug Alcohol Abuse2000; 26(1):66-75.
(16) Frank DA, Zuckerman BS, Amaro H, Aboagye K, Bauchner H, Cabral H,
Fried L, Hingson R, Kayne H, Levenson SM, et al Cocaine use during
pregnancy, prevalence and correlates, Pediatrics. 1988 Dec;82(6):888-95.
(17) Oro AS, Dixon, SD. Prenatal cocaine and methamphetamine exposure:
maternal and neo- natal correlates. Pediatrics 1987;111(4):571-8.
(18) Klassen, A., Sexual experience and drinking among women in a U.S.
national survey, Arch. Sex. Behav. 1986;15(5):363.
(19) Reardon DC. Psychological reactions reported after abortion. The Post
-Abortion Review1994; 2(3):4-8.
(20) Abortion information survey. Open Arms Newsletter. 1996 Spring.
(21) Speckhard, A. Psycho-Social Stress Following Abortion. 1987.
Kansas City, MO: Sheed & Ward.
Competing interests: No competing interests
Danish women have a shorter life expectancy than other nordic women,
and one reason for this is probably that danish women more often smoke. It
would have been interesting to see the data stratified for smoking habits,
as one would expect this to have a strong influence on fetal loss.
Competing interests: No competing interests