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690  November-December 2004 Family Medicine

Karl Miller, MDEditor, Letters to the Editor Section

 Editor’s Note: Send letters to the editor to MillerKE@erlanger.org or to my attention at Family Medicine Letters to the Editor Section, University of Tennessee, Chattanooga Unit, Department of FamilyMedicine, 1100 East Third Street, Chattanooga, TN 37402. 423-778-2957. Fax: 423-778-2959. Elec-tronic submissions (e-mail or on disk) are preferred. We publish Letters to the Editor under threecategories: “In Response” (letters in response to recently published articles), “New Research”(letters reporting original research), or “Comment” (comments from readers).

Le tte rs to the Ed itor 

In Response

Does Pregnancy Begin

at Fertilization?To the Editor:

The study by Wallace et al pro-vides insight into the knowledgeand attitudes of family medicineproviders of hormonal emergencycontraception (EC).1  However,there is an important issue about ECuse that the authors did not discuss.

The authors state “. . . EC is notan abortifacient . . .” because “ . . .research indicates the primary mode

of action of EC is via preimplanta-tion mechanisms.” This belief hasbeen supported by others who havepointed out “ . . . EC cannot disruptan established pregnancy . . .” andtherefore can never have an “abor-tifacient effect” because “. . . im-plantation marks the beginning of pregnancy.”2

Nevertheless, a postfertilization,preimplantation mechanism of ac-tion would be considered an abor-tifacient effect by providers or

women who believe pregnancy be-gins at fertilization. The Zogby sur-vey is just one of several recent na-tional surveys revealing that almosthalf (49%) of women in Americabelieve human life and pregnancybegins at fertilization.3 (In this let-ter we use the terms fertilization andconception synonymously.)

We have published a systematicreview of the mechanisms of action

of EC that concluded that it relies,at least to some extent, on apostfertilization, preimplantationeffect.4 Other researchers have pub-

lished similar conclusions. Surpris-ingly, this effect can occur whetherEC is taken before, during, or afterovulation. As is well known, thiseffect is more likely the longer thedelay between intercourse and theadministration of EC.4

We recognize that there are phy-sicians, geneticists, ethicists, andmedical organizations that have,within just the last 20 years, arbi-trarily defined human life as begin-

ning after implantation, thereby es-chewing the possibility of an abor-tifacient effect by EC by definition.However, others recognize the tra-ditional medical definition of preg-nancy as “the gestational process,comprising the growth and devel-opment within a woman of a newindividual from conception throughembryonic and fetal period to birth,”where conception is defined as “thebeginning of pregnancy, usuallytaken to be the instant that a sper-

matozoon enters an ovum andforms a viable zygote.”5

Wallace et al considered the “cor-rect” answer to the question “Doesthe research show EC acts as anabortifacient?” to be “No.” How-ever, this answer can only be cor-rect if they define pregnancy as be-ginning at implantation—and ig-nore or dismiss the beliefs of manyothers. For providers or patients

who believe pregnancy begins atfertilization, and who have followedthe literature on the mechanisms of action of EC, the correct answer to

this question would be “Yes.”The question as to whether EC

sometimes acts after fertilization toprevent implantation should be of significant moral significance tomost providers and patients. Evenstrong advocates of EC have ex-pressed their support for informingpatients about EC’s potential forpostfertilization effects.

Therefore, rather than implicitlydeclaring those who believe preg-

nancy begins at fertilization as sci-entifically “wrong” based on defi-nitions they do not accept (and area matter of scientific controversy),those who perform research in thisimportant area would be better off to recognize and respect closelyheld beliefs and account for them inboth their research and their provi-sion of informed consent about EC.Walter L. Larimore, MD

 Department of Family MedicineUniversity of Colorado HSC 

 Joseph B. Stanford, MD, MPH 

 Department of Familyand Preventive MedicineUniversity of Utah

Chris Kahlenborn, MD Department of Internal Medicine Altoona Hospital Altoona, Pa

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691Vol. 36, No. 10 Letters to the Editor 

REFERENCES

1. Wallace JL, Wu J, Weinstein J, Gorenflo DW,Fetters MD. Emergency contraception:knowledge and attitudes of family medicineproviders. Fam Med 2004;36(6):417-22.

2. Grimes DA. Switching emergency contra-ception from prescription only to over-the-counter. N Engl J Med 2002;347:846-9.

3. Zogby J. American values. Volume V. Utica,

NY: Zogby International, December 2000.4. Kahlenborn C, Stanford JB, Larimore WL.

Postfertilization effect of hormonal emer-gency contraception. Ann Pharmacother2002;36(3):465-70.

5) Mosby’s medical, nursing, and allied healthdictionary, sixth edition. Philadelphia:Mosby, 2002.

Authors’ Response:We acknowledge the concerns

expressed by Drs Larimore,Stanford, and Kahlenborn regard-ing the definition of abortifacientand the mechanism of action of 

emergency contraception (EC). TheAmerican College of Obstetrics andGynecology states that implantationis a necessary step in the establish-ment of a pregnancy and that abor-tifacient refers to the disruption of an implanted pregnancy.1 Accord-ing to this definition, which isshared by the Food and Drug Ad-ministration, the National Institutesof Health, and the majority of thegynecologic literature, EC is not an

abortifacient. We acknowledge thatsome providers may have alternatedefinitions and therefore may con-test the correct answer to one of oursurvey questions.

Regarding mechanism, the exactactions of EC on the fertilized oo-cyte are still being studied. Mostcurrent research suggests that themajority of the time, EC acts be-fore fertilization.2,3 However, undercertain circumstances, particularlywhen there is delay in initiating EC,

a postfertilization but preimplanta-tion mechanism may occur. The rel-evance of this possibility to our fe-male patients who are consideringuse of EC is uncertain and could bea question worthy of future re-search.

What is certain is that we as fam-ily physicians need to go beyondmedical terminology when discuss-

ing EC with our patients. We musthave open and honest conversationsin layman’s terms regarding EC, itsbenefits, and its potential conse-quences and let the patient make herown decision. The first step in fos-tering these important discussions

is to ensure residents have adequateknowledge and training regardingprovision of EC.

 Jennifer L. Wallace, MD Jamie Weinstein, MD

 Department of Family MedicineUniversity of Michigan

 Justine Wu, MD Department of Family MedicineUMDNJ-Robert Wood Johnson

 Medical School

REFERENCES

1. American College of Obstetrics and Gyne-cology. Statement on contraceptive methods,July 1998. Washington, DC: American Col-lege of Obstetrics and Gynecology, 1998.

2. Croxatto HB, Devoto L, Durand M, et al.Mechanism of action of hormonal prepara-tions used for emergency contraception: areview of the literature. Contraception 2001;63:111-21.

3. Marions L, Hultenby K, Lindell I, Sun X,Stabi B, Gemzell-Danielsson K. Emergencycontraception with mifepristone andlevonorgestrel: mechanism of action. ObstetGynecol 2002;100:65-71.

New Research

Family Physicians’ BeliefsAbout Genetic Testing

To the Editor:Since the inception of the Human

Genome Project (HGP) in 1989,appropriate concern has arisenabout how awareness of an in-creased genetic predisposition to adreaded disease might impact suchindividuals’ overall quality of life.The personal beliefs that clinicianshold about this important issue islikely to influence their enthusiasmfor this emerging field, and expo-sure to the cutting-edge genetic dis-coveries in medical school is likelyto catalyze the development of suchbeliefs. We examined whether thebeliefs held by the cohort of familyphysicians who received formalmedical school training since the

human genome era began differfrom those who trained earlier. Thedirection of any effect might repre-sent a trend that will have impacton the early uptake of genetics infamily medicine.

In 2002, we completed a mailed

survey of all 693 members of theMassachusetts Academy of FamilyPractice (MAFP) and attained a43% response rate. The MAFP rep-resents approximately 80% of thefamily physicians practicing inMassachusetts and demonstrates adiverse population as measured byage (range=30–86 years, mean/ standard deviation [SD]=45.8/7.8)and sex (40% female).

We provided the physicians withthe following scenario: “Consider

your patients who have a familyhistory of cancer. Assume that theyunderwent genetic testing andlearned that they had a high risk of developing that cancer sometime inthe future.” We then asked themwhether their patients “in general”would be more or less likely to “ex-perience an improved quality of life.” Response options included a4-point scale containing “muchmore likely,” “somewhat morelikely,” “somewhat less likely,” and

“much less likely.” They were alsogiven the option of “I can’t guess”positioned separate from the otherresponse options. For examinationof optimistic bias, responses weredichotomized to “more likely” ver-sus all else. Medical school train-ing period was dichotomized at agraduation year of 1993 to allow fora medical school start year of 1989to coincide with the HGP. We usedstandard chi-square to investigatecrude difference in optimistic biasby training period. We stratifiedthese results on sex and age to iden-tify possible confounding or effectmodification of our crude associa-tion. Ultimately, we used logisticregression analysis to adjust for theconfounding effect of age by strataof sex on the association betweentraining period and optimistic bias.We used SPSS Version 11.0® for all