When I read the headline yesterday, I was confounded. "Women May Ovulate More Than Once a Month," reported the international news service Reuters. The article explained that a new scientific study found most women ovulate two or three times, so it's impossible to predict ovulation, and this is why natural birth control doesn't work. Another news story even told the well-worn joke, "What do you call people who use natural family planning? Parents!"
I reacted as if someone told me two and two is five; it just didn't add up. I have used natural birth control successfully for nearly six years, and have seen clear signs of a single ovulation month after month. I teach natural birth control, and have looked at many women's charts, all of which report clear signs of fertility that my clients use to achieve or avoid pregnancy. I also recently published a comprehensive book about all birth control methods, Birth Control for Christians: Making Wise Choices. The multiple ovulation theory would contradict much of what I had written and researched.
Natural birth control has been important to Roman Catholics for decades, and is becoming increasingly popular among Protestants. Natural birth control involves monitoring a woman's cervical fluid and temperature, looking for the body's natural signals of fertility. Natural family planning users avoid all contraception, abstaining during fertile times to avoid pregnancy (this is the Catholic approach). Fertility awareness users may use condoms or diaphragms during fertile times (this approach is more often used by Protestants). Both approaches boast effectiveness rates ranging from 85 percent 99 percent—a big range, but effectiveness is highly dependent upon the couple using the method correctly and consistently. Couples who use natural birth control face naïve questions, jokes, and disbelief from their friends and family, and this new study seemed to add fuel to the fire.
As a professor, I require solid research from my students. I followed my own advice and hunted down the original research article, published in the July 2003 issue of Fertility and Sterility. The news stories I read simply got the story wrong. This study proposes a new model for understanding human ovulation. It is groundbreaking, fascinating, and important for women's health. It does not, however, say women ovulate more than once per cycle, nor does it draw any conclusions about the effectiveness of natural birth control.
More like mammals after all
Experts have long believed that human females ovulate differently than other mammals. Cows, pigs, and horses for example, have nearly constant ovarian functioning, some of which leads to ovulation. Scientists call this a "wave" pattern, that is, eggs are constantly maturing and dissolving, until one egg finally ovulates. Perhaps due to our distaste for comparing women to cows or pigs, humans were thought to be different. Women, it was believed, produced a small number of immature eggs only at the beginning of a menstrual cycle. One egg develops more successfully than the others, and it ovulates. In both of these models, estrogen and follicle stimulating hormone influence the development of eggs, and a third hormone, luteinizing hormone, surges and forces ovulation.
This new research may alter our understanding of this basic process by revealing that women, like other large mammals, ovulate in "waves." The Canadian research team, made up of two human reproduction researchers and the veterinarian who conducted cow ovulation studies in the 1980s, used results from 50 women in their study. The women agreed to allow researchers to watch the daily development of their eggs by using ultrasound technology.
Most women experienced either two or three "waves" of ovarian activity during one menstrual cycle. Eggs developed to a mature or nearly mature size, and then most dissolved. Only one wave of follicular (egg follicle) development resulted in ovulation, as a result of the surge in luteinizing hormone. Consistent with current knowledge, the egg that successfully ovulated was developed during the first half of the menstrual cycle (the approximately two-week period beginning with menstruation). The nonovulatory waves happened after ovulation (the approximately two-week period before ovulation).
What the study might change—and what it won't
If confirmed by additional studies, this research has potential to improve women's health, especially in the area of infertility. Some women undergoing infertility treatment use medications to stimulate the development of eggs. Sometimes those eggs are harvested for in vitro fertilization, that is, they are removed from the woman's body and inseminated, and then placed back in the body. Other assisted reproductive technologies stimulate egg development without egg harvesting. These treatments have been extremely time-sensitive, because scientists believed that there was only one opportunity per cycle to stimulate eggs. This research indicates that infertility treatments may use eggs produced during the second half of the cycle, resulting in a great increase in the number of eggs available for infertility interventions. This could significantly reduce the time couples spend pursuing infertility treatments.
These findings may also carry implications for birth control methods that intervene in the ovulation process (hormonal methods such as the pill or patch, injections, implants, and hormone-releasing IUDs).
Media reports that say this study confirms the ineffectiveness of natural birth control are false. Because, in their mistaken view, women ovulate numerous times per month, it is then impossible for women to identify their fertile times. However, women do not ovulate more than once per menstrual cycle (except on the rare occasions when two eggs are released at the same time, which may result in twins). Each ovulation is associated with growth of the uterine lining, which must either result in a pregnancy or be shed in menstruation before another ovulation may occur. The ovulatory wave of follicular activity is associated with changes in a woman's temperature, cervical fluid, and cervix position, all of which may be charted with great accuracy. This is because when an egg is preparing to ovulate, several other hormones are at work producing these physical changes. The nonovulatory waves of follicular activity are not noticed by natural family planning methods. In the second half of a woman's cycle, different hormones are at work, and these do not produce fertile symptoms.
This new ovulation study carries more immediate implications for infertility and for hormonal birth control than for natural birth control. Natural birth control was developed in the mid-20th century by two Roman Catholic scientists who wondered why the rhythm method was so ineffective. The rhythm method involves counting days on a calendar, assuming fertility in the middle of a cycle. Contemporary methods use daily knowledge of the body's symptoms of fertility—with no assumptions based on cycle length. Attention to cervical fluid and temperature is a scientific approach that has entirely replaced the rhythm method, with wonderful increases in effectiveness.
This news will not change most women's daily lives, attention to their menstrual cycles, or their contraceptive choices. Women should be alert, however, for changes in contraception, infertility treatments, and basic medical knowledge that may come as a result of this pathbreaking study. Perhaps even more important, Christians should be alert to ways in which media biases, naïveté, and rushed research may misconstrue the facts.
Jenell Williams Paris is a fertility awareness instructor and author of Birth Control for Christians: Making Wise Choices (Baker Books, 2003). She is also associate professor of anthropology at Bethel College in St. Paul, Minnesota.
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Paris's Birth Control for Christians can be purchased at Christianbook.com and other book retailers.
Paris earlier wrote for Christianity Today on the sexual lies our culture proclaims—and which seduce even Christians.
Christianity Today's recent articles on contraception and fertility include:
Make Love and Babies | The contraceptive mentality says children are something to be avoided. We're not buying it. By Sam and Bethany Torode (Nov. 9, 2001)
'Be Fruitful and Multiply' | Is this a command, or a blessing? By Raymond C. Van Leeuwen (Nov. 9, 2001)
Souls on Ice | The costs of in vitro fertilization are moral and spiritual—not just financial (June 24, 2003)
400K and Counting | Christians recoil at explosive growth of frozen human embryos (June 24, 2003)
Books & Culture Corner: More Sex, Fewer Children | Mixed messages on condoms, contraception, and fertility. By John Wilson (Sept. 10, 2001)
How to Make a Person | New reproductive technologies raise difficult moral issues. (Jan. 6, 1997)
Mourning the Morning-After Pill | A Christianity Today Editorial (Apr. 7, 1997)
Charity Defies California Law on Contraception | Court to decide if state can require Catholic ministries to pay for birth control (June 25, 2002)
No Room in the Womb? | Couples with high-risk pregnancies face the 'selective reduction' dilemma (dec. 10, 1999)
Hannah's Sisters | At a Washington Assembly of God, prayers for fertility are answered (Mar. 21, 2002)
Embryo 'Adoption' Matches Donors and Would-be Parents | 'Snowflake' program is only of its kind in dealing with leftover fertilized eggs (Nov. 2, 1999)
For more current news on fertility and pregnancy, see Yahoo's full coverage area.