Fertility after Childbirth
During the approximate 9 months of pregnancy, a woman's body has been nourishing and sustaining the life of her baby in her womb. During pregnancy, the woman is not in a fertile state. Once the baby is born, however, the return of fertility will be different for each woman. There are a number of factors that influence the speed of return of fertility. One of the key factors for the return of fertility is whether a woman breast-feeds her infant or not. The doctors and nurses at Tepeyac Family Center encourage women to breast-feed their babies, because it is one of the healthiest things she can do for herself and her baby. Breast-feeding helps the mother return to normal physiology quicker and enhances the bond between her and her baby. For the baby, breast-feeding helps to prevent infections and is physiologically compatible. However, we do realize that not all mothers can or should breast-feed their infant.
If a mother is totally breast-feeding her infant (that is, if the baby is only fed breast milk by the mother and the mother uses the breast for pacification) and if she does not have a return of menses (bleeding), then she will have less than a 2% chance of being fertile in the first 6 months after birth. This guideline for breast-feeding was established by the World Health Organization.
As fertility approaches, the woman might experience more frequent signs of mucus, the mucus will become more abundant, and the mucus will take on peak signs (i.e., become clear, slippery, and stretchy). The temperature will also begin to level off. These signs are a reflection of rising levels of estrogen. Factors that will signal or lead to the return of fertility are:
- less-frequent breast-feeding;
- the baby is introduced to new foods;
- the baby sleeps through the night;
- stress, anxiety, or illness in the mother.
Up to 40% of women will not experience blood loss before the first ovulation. The first few cycles after the first ovulation will vary in length and the pattern of cervical mucus will most likely be different than what was experienced before pregnancy. Variability of cycle lengths and cervical mucus will be more pronounced in women who continue to breast-feed from time to time. Some women will experience continuous mucus and will need further help from their NFP teachers. The following are general instructions for avoiding pregnancy in the first cycle after fertility returns:
- Allow 6-9 weeks after birth and bleeding to dry up before resuming intercourse.
- Have intercourse only at the end of the day (evenings) on dry days before ovulation (i.e., before the Peak Day or temperature shift).
- Before ovulation, consider any day of mucus and 3 days past as fertile.
- Be consistent in observing and charting your fertility signs (mucus and temperature).
- If using temperature: intercourse may resume after the evening of the 4th day of high temperatures past peak in the first fertile cycle after birth.
- If using the Clearplan Monitor or LH testing: intercourse may resume on the evening of the 4th day past the LH surge (i.e. the Clearplan Monitor LH Peak Day).
- If using cervical mucus signs only: continue to have intercourse at the end of the day on dry days only during the first cycle. In subsequent cycles, if the woman is confident that it is her peak day of cervical mucus, then intercourse may resume on the evening of the 4th day past peak and then anytime on the day after that.
- Treat any mucus days and the 3 days after as fertile.
We recommend that all women (whether breast-feeding or not) begin to observe and chart their signs of fertility as soon as the bleeding dries up after the birth of a baby. The temperature shift and the urinary LH surge will not be present during this time, because a woman is not ovulating. A woman should, however, observe and chart her cervical mucus observations and, if she likes, her basal body temperature. Before the return of fertility a woman usually will observe long periods of dryness with occasional mucus days. Some women experience an unchanging pattern of a moist sensation or constant presence of mucus.
Please keep in mind that it will take 2-3 cycles before the variability of cycle length and of mucus pattern normalizes. If you are experiencing a continuous pattern of mucus and are confused with your fertility signs – then see your NFP teacher!
Source: Marquette University Institute for Natural Family Planning