Moral Guidelines on the Use of the Standard Days Method

as Natural Family Planning



“I will instruct you and teach you in the way you should go; I will counsel you with my loving eye on you.” (Ps. 32:8)


In everything the Lord, the eternal Wisdom of God, is our teacher who guides our steps, prompting our mind and heart with his divine counsel to embrace the way of God’s holiness. We seek his divine guidance as we clarify the suitability of the use of the Standard Days Method (SDM) as an expression of a prudent and appropriate response to the charge by which married couples are invited by God to participate in his divine act to transmit life and educate children as testimony of their mutual love for each other in God (CCC §2367).


Description of the Standard Days Method


The Standard Days Method (SDM) is a simple new fertility-awareness-based system of family planning developed at Georgetown University Institute for Reproductive Health. SDM is reported to be 95% effective when used correctly. Correct usage of the SDM refers to the abstention of marital couple from sexual intercourse on days 8 through 19 of the menstrual cycle of the wife, where day 1 is the day when her period first begins, if they do not want to get pregnant. The fixed day algorithm for the SDM is based on statistical evidence that ovulation occurs around the middle of the cycle for menstrual cycles that have lengths between twenty-six and thirty two days. The average length of a woman’s cycle is 27.7±3.4 days. Theoretically, the SDM will be most effective when the day of ovulation falls closer to the center of the menstrual cycle.


When used correctly over a course of several years, SDM is comparable in its effectiveness to hormonal contraceptives: SDM has a rate of 5.1 unintended pregnancies per 100 couples in the second year of use, while one study has shown that oral hormonal contraceptives have a rate of 4.8 unintended pregnancies per 100 couples. In other words, if 100 couples used SDM correctly and consistently during the course of a year, five of them would become pregnant. The method is 88% effective when couples did not always abstain during the entire fertile time.


A couple can track their fertility for the Standard Days Method manually with a calendar, or with CycleBeads. CycleBeads, which consists of thirty-two beads in three colors, is a fertility awareness-tool that helps a couple plan or prevent pregnancy as they track the woman’s menstrual cycle. It is a non-hormonal and non-invasive way to monitor fertility, with no detrimental side effects to a woman’s health. However, a couple will need to use a different method of natural family planning if the woman has more than one cycle per year that is either shorter than 26 days or longer than 32 days.


Moral Teaching of the Catholic Church


As the Catechism of the Catholic Church teaches, human sexuality is ordered to the conjugal love of man and woman (§2360). The union of the spouses in the conjugal act achieves the twofold ends of marriage which are the good of the spouses themselves and the begetting of children (§2363). Called to give life, spouses share in the creative power and fatherhood of God: “Married couples should regard it as their proper mission to transmit human life and to educate their children; they should realize that they are thereby cooperating with the love of God the Creator and are, in a certain sense, its interpreters. They will fulfill this duty with a sense of human and Christian responsibility” (§2367). Thus, married couples should always be open to the gift of children.


However, the Catechism also notes that for just reasons, “spouses may wish to space the births of their children” (§2368). Couples have the duty to make certain that their desire is not motivated by selfishness but is in conformity with the generosity appropriate to responsible parenthood, and they have to conform their behavior to an objective criterion of morality (cf. §2368). Just reasons can include economic and medical considerations.


Finally, the Catechism teaches: “Periodic continence, that is, the methods of birth regulation based on self-observation and the use of infertile periods, is in conformity with the objective criteria of morality. These methods respect the bodies of the spouses, encourage tenderness between them, and favor the education of an authentic freedom (§2370).”


Moral Evaluation of the Standard Days Method


The Standard Days Method is a method where couples refrain from sexual intercourse for eleven days every month. It is a method of periodic continence that is based on the use of infertile periods. As the Catechism acknowledges, methods such as the SDM are in conformity with the objective criteria of morality. As such, the Standard Days Method is morally licit and is in accordance with the Gospel of Life.


The Standard Days Method also promotes other dimensions of the common good. Like other methods of natural family planning, SDM promotes virtue and self-mastery in the family. Couples discover that human sexuality is a gift from God that should not be used indiscriminately. If we are to give love, it must always be open to love. If we are to give life, it must always be because of love.


User experience also suggests that SDM use is empowering for many women. Knowledge about their bodies and menstrual cycles that gives them the ability to plan for or to prevent pregnancy has increased women’s self-confidence and their ability to care for their own health and the health of their families. In many cases, SDM makes it possible for women to talk openly with their husbands about how to manage fertile days to avoid pregnancy, maybe even for the first time.


Finally, it is important to stress that the morality of any public program that promotes SDM would be lethally compromised if the program simultaneously encouraged couples to use barrier methods (i.e., condoms, alongside with or as a backup plan for SDM) or, if its use should lead to a contraceptive mentality. If the couple’s idea is that SDM is simply one of the contraceptives one can choose from, then there is no difference will it have with the use of condoms and other contraceptives. What makes the use of the natural means evil is the intention of its use. The moral absolute tells us that if anything by nature is good but the intention is evil then it becomes an immoral act.


An Exhortation


Let this counsel flowing from the fountain of God’s wisdom, “dwell among you richly as you teach and admonish one another with the psalms and hymns” of your lives steadfast in the Lord, “singing to God with gratitude in your hearts (cf. Col 3:16).” Everything that we act and do we must do in the spirit of praise and thanksgiving to the Lord for ours is an existence that is a gift from the divine and its perfection is not sought and achieved apart from God. Doing so “is good, and pleases God our Savior, who wants all people to be saved and to come to acknowledge of the truth” (1 Tim 3-4).


From the Catholic Bishops’ Conference of the Philippines, September 16, 2016



Archbishop of Lingayen Dagupan

President, CBCP

The Catholic Bishops' Conference of the Philippines

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