In the past, most women nursed their children for about two years, and nursing would almost always prevent ovulation and menstruation. Consequently, a woman could not become pregnant while nursing, and there was thus a natural gap of about two years between birth and the next pregnancy. Today, reality has changed in two ways. First, the average time spent nursing has been shortened to six months or less. There are several reasons for this: women have joined the workforce, life is more stressful, and substitutes for breast milk are available. Second, for many women, nursing does not prevent ovulation and menstruation, so they can become pregnant even while nursing.
Thus, if a couple fulfill the mitzva of ona at its set times, many women would conceive a few months after giving birth, especially women who are not nursing at all or are nursing some of the time and supplementing with formula. The question arises: may a couple use contraception in the year following birth, to enable them to fulfill the mitzva of ona while avoiding another pregnancy?
Some rabbis are inclined to rule stringently and do not permit birth control except if there is a great need, such as when the mother is extremely weak or very stressed. In their opinion, the mitzva of procreation requires having as many children as possible. However, the halakha follows the opinion of most poskim, who maintain that when necessary it is permissible to prevent pregnancy using halakhically acceptable methods (as explained in sections 17-19). Experience shows that from the perspective of physical and psychological health, it is best for most women to take a break of approximately nine months to a year between birth and the next pregnancy. Accordingly, it is permissible le-khatḥila for all women to use contraceptive methods during this time. Similarly, after a miscarriage, birth control may be used for several months if necessary, based on the instruction of a God-fearing doctor.
. The parameters of family planning are not addressed systematically in the halakhic literature; rather, we find numerous responses given to different people in a variety of situations. This is primarily because it is a subject that has surfaced in recent times. Thanks to medical advances and improved living conditions and nutrition, the average woman can have many more children than in the past (as explained above, at the beginning of n. 6). Additionally, many feel that since the subject is very complex, a wise person should always be consulted. Accordingly, there is no need to write general parameters (as explained below, in section 20). It is also important to note that many rulings deal with contraceptive methods that raise concerns about wasting seed, and not with birth control pills and IUDs, which avoid this problem because they are akin to the talmudic sterility potion (kos shel ikarim); see section 17 below. Nevertheless, three general opinions emerge from these rulings. The most stringent approach maintains that contraception should not be used unless there is a great need. Only natural means like nursing should be used (including after birth). Other means of contraception may be used only in cases of physical illness or psychological fragility (Shevet Ha-Levi 3:177; Mishneh Halakhot 5:210). At the other extreme are those who permit the use of contraception for two years following a birth, even before the mitzva of procreation has been fulfilled. They see it as natural, and also what was done throughout history. Women generally nursed for two years (Nidda 9a), and the nursing had a contraceptive effect (Si’aḥ Naḥum §94; Bnei Banim 1:30). The moderate approach is that it is permissible le-khatḥila to use contraception for nine months to a year following a birth. This allows the mother to recuperate from the birth and to take proper care of the baby, both of which are very important. Even a woman who does not feel it is necessary may still use birth control le-khatḥila for this amount of time, since experience shows that it is in fact necessary. In special cases of physical or psychological fragility, contraception may be used for up to two years. It seems most rabbis rule by this approach (see Nishmat Avraham, EH 5:16 n. 1).