Contraceptive use and breast-feeding duration in rural Bangladesh

Abstract

The association between contraceptive use and breast-feeding duration was investigated in 2380 women in rural Bangladesh where women usually stop breast-feeding once pregnant. Life table analysis showed that women receiving regular injections of depo medroxy progesterone acetate (DMPA) and those using non-hormonal contraception breast-fed significantly longer than women using no contraception. In contrast, women using oral contraceptives (combination of 0.5 mg norgestrel and 0.05 mg ethinyl oestradiol) did not breast-feed longer than women using no contraception. It is suspected that prolongation of breast-feeding obtained by delaying the next pregnancy with this oral contraceptive was offset by the depressing effect of oestradiol on lactation. Thus, in communities where prolonged breast-feeding is associated with improved child survival, non-hormonal contraceptive methods, or injectable DMPA, should be preferred for lactating women to oestrogen-containing oral contraceptives. PIP:

Researchers used the life table method to analyze data on 2380 lactating women with at least 1 5 year old child alive in March 1988 to examine the association between contraceptive use and lactation in rural Matlab, Bangladesh. 51.6% of the women used the contraceptive method of 3 monthly intramuscular injections of 150 mg depo medroxy progesterone acetate (DMPA). 23.7% used a combined oral contraceptive (COC) (.5 mg norgestrel and .05 ethinyl estradiol). 24.6% used a nonhormonal method, especially tubectomy and IUDs. Women who did not use contraceptive were more likely to be pregnant when they stopped breast feeding (47.8%) than their counterparts who had used contraception (5.5%) (p.001). Women who used a nonhormonal method or received DMPA breast fed a mean of 43 and 45 months respectively which compared to the duration of mothers who did not use contraception and were not pregnant at the end of the follow up (44 months). Mothers who did not use contraception and were pregnant at then end of the follow up breast fed on average 31 months. Therefore pregnancy was a common cause for breast feeding cessation. DMPA users breast fed significantly longer than women not using contraceptives (45 months vs. 40 months) (p.001). Further nonhormonal contraceptive users had a significantly longer breast feeding duration than noncontraceptive users (p.01). These associations remained significant even after adjusting for parity and maternal education (p.001 and p=.024 respectively). On the other hand, COC users breast fed on average 40 months which was similar to the mean duration of noncontraceptive users. In fact, COC use significantly increased breast feeding cessation when the researchers adjusted for pregnancy or excluded women who were pregnant at the end of the follow up (p.001). The researchers believed that cessation occurred with COC users because estradiol depressed lactation rather than contraceptive failure. In conclusion, contraceptive use delays pregnancy which in turn protects breast feeding and may improve child survival.