Jan. 1, 2001 -- Nathan and Kathy Sendan begin each day with a
pen, paper, and digital thermometer. The El Sobrante, Calif., couple dutifully
record Kathy's basal body temperature before they even think of drinking their
morning coffee. Then they combine the temperature readings with other
physiological data to track Kathy's fertility cycle and, in effect, to time
Such is the routine for those who practice natural family
planning, a method that shuns hormones, condoms, and other artificial forms of
birth control. It is the only form of contraception given the stamp of approval
by the Catholic Church, but many proponents see a growing interest among
non-Catholics as well.
The birth control pill was a big hit when it went on sale in the early 1960s. Nearly 50 years later it's still one of the most popular methods of reversible birth control, with dozens of brands and formulations available.
And, as with any celebrity, half-truths and misconceptions have attached themselves to the pill. Perhaps none are more lingering than the myth that birth control pills can lead to weight gain.
What’s the truth about birth control pills and weight gain?
Joseph Stanford, MD, assistant professor of family and
preventive medicine at the University of Utah and former president of American
Academy of Natural Family Planning, estimates that as many as 40% of those now
practicing this technique are non-Catholics. Natural family planning
"offers an alternative where you don't have to mess up your physiology --
you're more in tune with your body, and there are no side effects,"
"It's not just a Catholic thing anymore," says Patrick
Homan, the western region field director for the Couple to Couple League, an
Ohio-based institute whose 1,351 teachers offer instruction on natural family
planning. "Our numbers have been going up for the last five to six
Indeed, the Sendans are not Catholic, but they chose natural
family planning because of dissatisfaction with the pill. "I liked the idea
of not putting chemicals in my body," says Kathy Sendan.
She recalls being "grumpy all the time" during the
three years she was taking oral contraceptives. She also had a more specific
health concern: "I have epilepsy, and the [antiseizure medication could]
have made the birth control pill less effective," she says.
Numbers Remain Small
To be sure, the number of people choosing natural family
planning still remains small. According to a 1995 survey conducted by the
National Center for Health Statistics, only 1.5% of women aged 15-44 reported
using periodic abstinence as a means of contraception. That trails the 17.3% of
women choosing the pill, the most popular form of reversible contraception.
Female sterilization was the most popular method at 17.8%, followed by the
condom at 13.1%. Advocates of natural family planning say their efforts are
hampered by the stigma of the "old" calendar rhythm method, which
relied on the expectation that ovulation occurs on Day 14 of a 28-day cycle,
and resulted in numerous "surprise" pregnancies.
In fact, menstrual cycles can vary from one woman to the next,
and for many women, from one month to the next. Stress or illness, for
instance, can disrupt even the most regular cycles. Such inherent variability
was recently demonstrated in a study of 221 healthy women, published in the
British Medical Journal in November 2000. Using daily urine tests to
check for hormonal evidence of ovulation, researchers from the National
Institute of Environmental Health Sciences found that even though clinical
guidelines assume the average woman is fertile between days 10 and 17 of her
menstrual cycle, only 30% of the women studied had their window of fertility
fall entirely within that time period. Even women with reportedly regular
cycles had a 10% chance of being fertile "on any given day of their cycle
between days six and 21," the researchers wrote.
"What was surprising to us is the fact that not only were
fertile days coming early in the cycle, but late when a woman thinks she's on
the end of her cycle," says Allen J. Wilcox, MD, PhD, chief of epidemiology
at the NIEHS and lead author of the study. "We're just putting numbers on
something people had a sense of before."
The researchers also point out that most of the women in the
study were between the ages of 25 and 35. Teenagers and women nearing menopause
tend to have even more unpredictable cycles.