Beginning of pregnancy controversy - Women

February 9, 2012


		1 Introduction 2 Definitions of pregnancy beginning 3 Types of contraception 4 Ethics of preventing pregnancy 5 In vitro fertilisation and detectable pregnancy 6 Viability and established pregnancy 7 Notes

Women Women

Beginning of pregnancy controversy

Wikipedia

Controversy over the beginning of pregnancy usually occurs in the context of the abortion debate. Different definitions are used to define certain birth control methods as either contraceptives or abortifacients, because of their possible post-fertilisation effects.

[go back to top]

Definitions of pregnancy beginning

Traditionally, doctors have measured pregnancy from a number of convenient points, including the day of last Menstrual cycle|menstruation, ovulation, fertilisation, implantation and chemical detection. This has led to some confusion about the precise length of human pregnancy, as each measuring point yields a different figure.

The definition of pregnancy as starting from implantation has been adopted by the American Medical Association. Likewise, the British Medical Association defines pregnancy from implantation,<ref name="BMA1999-abortion-objection">cite web | author=British Medical Association | authorlink=British Medical Association | title=The law and ethics of abortion: Conscientious objection clause | year=1999 | month=December | url=http://www.bma.org.uk/ap.nsf/Content/abortion~objection</ref><ref name="BMA2005-AbortionTimeLimit">cite web | author=BMA | authorlink=British Medical Association | title=Abortion time limits: A briefing paper from the British Medical Association | year=2005 | month=May | url=http://www.bma.org.uk/ap.nsf/Content/AbortionTimeLimits</ref> and this is the legal definition in the United Kingdom.<ref>cite web | author =Hope, T. and Savulsecu, J. | url=http://www.ethox.org.uk/education/teach/pregnancy/pregnancy3.htm | title =Handout 3: Outline of Legal Positions in England and Wales | work =Medical Ethics and Law Teaching Materials: Termination of Pregnancy | pages =Appendix 3: Some key points in the law on abortion and fetal damage | publisher =The Oxford Centre for Ethics and Communication in Health Care Practice, Oxford University - See the section 'Inter-uterine contraceptive devices (IUCDs) and "morning after" pills'</ref>

Despite this, other definitions are frequently used. The American Heritage?? Stedman's Medical Dictionary defines "pregnancy" as "from conception until birth." <ref>The American Heritage?? Stedman's Medical Dictionary, 2002</ref> Prominent medical textbooks such as Langman's Medical Embryology count pregnancy from fertilisation,<ref>O'Brian, Patrick and Thomas Sadler. Langman's Medical Embryology. Lippincott Williams & Wilkins (2004), p. 117.</ref>
Professionals have also debated the issue in medical journals.<ref> Larimore, Walter L., MD, et al. http://www.stfm.org/fmhub/fm2004/November/Walter690.pdf "Response: Does Pregnancy Begin at Fertilization?" Family Medicine, November-December 2004.</ref>

Finally the standard historical method of counting the gestational age|duration of pregnancy begins from the last menstruation and this remains common with doctors, hospitals, and medical companies.<ref>Doctorcite web | author=George P. Pettit, M.D. | title=Due Date Calculator | year=2002 | url=http://www.drpettit.com/ddcalc.html<br />
Hospitalcite web | author=Northwestern Memorial Hospital | title=What is a trimester? | year=2006 | url=http://www.nmh.org/nmh/adam/pregnancy/000006.htm<br />
Medical companycite web | author=The Merck Manuals Online Medical Library | title=Stages of Development: Pregnancy | year=2003 | url=http://www.merck.com/mmhe/sec22/ch257/ch257c.html</ref> However in this system, ovulation and fertilisation do not occur until 2 out of the 40 weeks counted have passed.

[go back to top]

Types of contraception

Birth control methods usually prevent either fertilisation or implantation. Those that prevent fertilisation cannot be seen as abortifacient because, by any of the above definitions, pregnancy has not started. However, some agents have a proposed back-up effect of preventing implantation and thus destroying the blastocyst, and are therefore labeled as abortifacient by those that classify the start of pregnancy as fertilisation.

Possibly affected birth control methods

Hormonal contraception works primarily by preventing ovulation, but may have a secondary effect of interfering with implantation of embryos.

Intrauterine devices work primarily by spermicidal/ovicidal effects, but may have a secondary effect of interfering with the development of pre-implanted embryos.

The Lactational Amenorrhea Method works primarily by preventing ovulation, but is also known to cause luteal phase defect (LPD). LPD is believed to interfere with the implantation of embryos.<!--

Fertility awareness methods work primarily by preventing conception, but it has been speculated they have a secondary effect of creating embryos incapable of implanting (due to aged gametes at the time of fertilisation).<!--

[go back to top]

Ethics of preventing pregnancy

The intention of a woman to prevent pregnancy is an important factor in whether or not the act of contraception is seen as abortive by some pro-life groups. Hormonal contraceptives, including emergency contraception, have a possible effect of preventing implantation of a blastocyst, as discussed previously. Use of these drugs with the intention of preventing pregnancy is seen by some pro-life groups as immoral. This is because of the possibility of causing what they believe to be an abortion.<ref>cite web | last = Finn | first = J.T. | title = "Birth Control" Pills cause early Abortions | work = Pro-Life America ??? Facts on Abortion | publisher = prolife.com | date = 2005-04-23 | url = http://www.prolife.com/BIRTHCNT.html | accessdate = 2006-08-25 </ref>

However, hormonal contraception can also be used as a treatment for various medical conditions. When implantation prevention is unintentionally caused as a side effect of medical treatment, such pro-life groups do not consider the practice to be immoral, citing the bioethical principle of double effect.<ref>http://www.epm.org/articles/BreastfedAbortions.html Doesn't breastfeeding do the same thing as the Pill? Eternal Perspective Ministries, 2006. Accessed May 2006.</ref> A related application of the principle of double effect is breastfeeding. Breastfeeding greatly suppresses ovulation, but eventually an ovum is released. Luteal phase defect, caused by breastfeeding, makes the uterine lining hostile to implantation and as such may prevent implantation after fertilisation.<ref name="Diaz, S. et. al"/> Some pro-choice groups have expressed concern that the movement to recognize hormonal contraception|hormonal contraceptives as abortifacient will also cause breastfeeding to be considered an abortion method.<ref>cite web | title=Emergency Contraception & Conscience: Christian Right Attacks on Contraceptives | work=About.com Religion & Spirituality Agnosticism / Atheism | url=http://atheism.about.com/od/abortioncontraception/p/MorningAfter.htm | accessdate=2006-06-22</ref><ref>cite news | first=Russell | last=Shorto | title=Contra-Contraception | pages=4 of 9-page online article | date=May 7, 2006 | publisher=New York Times Magazine | url=http://www.nytimes.com/2006/05/07/magazine/07contraception.html?pagewanted=1&ei=5088&en=fd92772f01a5c709&ex=1304654400&adxnnl=0&partner=rssnyt&emc=rss&adxnnlx=1151015936-QF5/uHStQAb9tAkPSzv7uw </ref>

[go back to top]

In vitro fertilisation and detectable pregnancy

The advent of in vitro fertilisation allowed fertilisation to occur in a Petri dish instead of inside a woman. This clearly made fertilisation an event that did not automatically result in pregnancy.

All early pregnancy tests detect human chorionic gonadotropin (hCG), a hormone that is not secreted until after implantation. Defining pregnancy as beginning at implantation thus makes pregnancy a condition that can be tested for.

[go back to top]

Viability and established pregnancy

A related issue that comes up in this debate is how often fertilisation leads to an established, viable pregnancy. Current research suggests that fertilised embryos naturally fail to implant some 30% to 60% of the time.<ref>Kennedy, T.G. http://publish.uwo.ca/~kennedyt/t108.pdf Physiology of implantation. <u>10th World Congress on in vitro fertilisation and assisted reproduction</u>. Vancouver, Canada, 24-28 May 1997.</ref> Of those that do implant, about 25% are miscarriage|miscarried in the first two weeks after pregnancy can be detected.<ref>Wilcox AJ, Baird DD, Weinberg CR. Time of implantation of the conceptus and loss of pregnancy. New England Journal of Medicine. 1999;340(23):1796-1799. PMID 10362823.</ref> As a result, the majority of zygotes never result in established pregnancies, much less birth.

[go back to top]

Notes

<references />

Category:Abortion
Category:Birth control
Category:Pregnancy

[go back to top]

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Beginning of pregnancy controversy".

Last Modified: 2006-10-01

All informatin on the site is © www.woman-health.org 2002-2011. Last revised: January 2, 2011
Are you interested in our site or/and want to use our information? please read how to contact us and our copyrights.
To let us provide you with high quality information, you can help us by making a more or less donation: