Prolonged and exclusive breastfeeding reduces the risk of infectious diseases in infancy. Promotion of Breastfeeding Intervention Trial (PROBIT): a randomized trial in the Republic of Belarus. Effect of exclusive breastfeeding and complementary feeding on infant growth and morbidity. The first six month growth and illness of exclusively and non-exclusively breast-fed infants in Nigeria. Effect of community-based promotion of exclusive breastfeeding on diarrhoeal illness and growth: a cluster randomised controlled trial. Mother-to-child transmission of HIV-1 infection during exclusive breastfeeding in the first 6 months of life: an intervention cohort study. Effects of age of introduction of complementary foods on infant breast milk intake, total energy intake, and growth: a randomised intervention study in Honduras. Breast-feeding, return of menses, sexual activity and contraceptive practices among mothers in the first six months of lactation in Onitsha, South Eastern Nigeria. Prolonged exclusive breast feeding and heredity as determinants in infantile atopy. [Promotion of breast-feeding in urban localities of southern Brazil: a randomized intervention study]. Prolonged breast-feeding and malnutrition among rural Indian children below 3 years of age. Randomized, controlled trial of a prenatal and postnatal lactation consultant intervention on duration and intensity of breastfeeding up to 12 months. Randomized trial of donor human milk versus preterm formula as substitutes for mothers' own milk in the feeding of extremely premature infants. Nutrient enrichment of mother's milk and growth of very preterm infants after hospital discharge. Randomized, controlled trial of slow versus rapid feeding volume advancement in preterm infants. Breastfeeding pattern and the duration of lactational amenorrhea in urban Chilean women.
To examine the associations of duration of exclusive breastfeeding with infections in the upper respiratory (URTI), lower respiratory (LRTI), and gastrointestinal tracts (GI) in infancy.
                This study was embedded in the Generation R Study, a population-based prospective cohort study from fetal life onward in the Netherlands. Rates of breastfeeding during the first 6 months (never; partial for <4 months, not thereafter; partial for 4-6 months; exclusive for 4 months, not thereafter; exclusive for 4 months, partial thereafter; and exclusive for 6 months) and doctor-attended infections in the URTI, LRTI, and GI until the age of 12 months were assessed by questionnaires and available for 4164 subjects.
                Compared with never-breastfed infants, those who were breastfed exclusively until the age of 4 months and partially thereafter had lower risks of infections in the URTI, LRTI, and GI until the age of 6 months (adjusted odds ratio [aOR]: 0.65 [95% confidence interval (CI): 0.51-0.83]; aOR: 0.50 [CI: 0.32-0.79]; and aOR: 0.41 [CI: 0.26-0.64], respectively) and of LRTI infections between the ages of 7 and 12 months (aOR: 0.46 [CI: 0.31-0.69]). Similar tendencies were observed for infants who were exclusively breastfed for 6 months or longer. Partial breastfeeding, even for 6 months, did not result in significantly lower risks of these infections.
                Exclusive breastfeeding until the age of 4 months and partially thereafter was associated with a significant reduction of respiratory and gastrointestinal morbidity in infants. Our findings support health-policy strategies to promote exclusive breastfeeding for at least 4 months, but preferably 6 months, in industrialized countries. Current evidence that breastfeeding is beneficial for infant and child health is based exclusively on observational studies. Potential sources of bias in such studies have led to doubts about the magnitude of these health benefits in industrialized countries.
                To assess the effects of breastfeeding promotion on breastfeeding duration and exclusivity and gastrointestinal and respiratory infection and atopic eczema among infants.
                The Promotion of Breastfeeding Intervention Trial (PROBIT), a cluster-randomized trial conducted June 1996-December 1997 with a 1-year follow-up.
                Thirty-one maternity hospitals and polyclinics in the Republic of Belarus.
                A total of 17 046 mother-infant pairs consisting of full-term singleton infants weighing at least 2500 g and their healthy mothers who intended to breastfeed, 16491 (96.7%) of which completed the entire 12 months of follow-up.
                Sites were randomly assigned to receive an experimental intervention (n = 16) modeled on the Baby-Friendly Hospital Initiative of the World Health Organization and United Nations Children's Fund, which emphasizes health care worker assistance with initiating and maintaining breastfeeding and lactation and postnatal breastfeeding support, or a control intervention (n = 15) of continuing usual infant feeding practices and policies.
                Duration of any breastfeeding, prevalence of predominant and exclusive breastfeeding at 3 and 6 months of life and occurrence of 1 or more episodes of gastrointestinal tract infection, 2 or more episodes of respiratory tract infection, and atopic eczema during the first 12 months of life, compared between the intervention and control groups.
                Infants from the intervention sites were significantly more likely than control infants to be breastfed to any degree at 12 months (19.7% vs 11.4%; adjusted odds ratio [OR], 0.47; 95% confidence interval [CI], 0.32-0.69), were more likely to be exclusively breastfed at 3 months (43.3% vs 6.4%; P<.001) and at 6 months (7.9% vs 0.6%; P =.01), and had a significant reduction in the risk of 1 or more gastrointestinal tract infections (9.1% vs 13.2%; adjusted OR, 0.60; 95% CI, 0.40-0.91) and of atopic eczema (3.3% vs 6.3%; adjusted OR, 0.54; 95% CI, 0.31-0.95), but no significant reduction in respiratory tract infection (intervention group, 39.2%; control group, 39.4%; adjusted OR, 0.87; 95% CI, 0.59-1.28).
                Our experimental intervention increased the duration and degree (exclusivity) of breastfeeding and decreased the risk of gastrointestinal tract infection and atopic eczema in the first year of life. These results provide a solid scientific underpinning for future interventions to promote breastfeeding. A cohort study was conducted in the Islamic Republic of Iran between January 1997 and February 1998 to compare the growth and morbidity of 100 infants who were exclusively breastfed for 6 months and 100 who received breast milk and complementary foods between 4-6 months. Infants' feeding pattern, weight and height were assessed and recorded. There were no significant differences in infants' weight and height gain between 4 and 6 months. The rate of diarrhoea between ages 4 and 6 months was significantly lower in exclusively breastfed infants than in complementary food-fed infants (11% versus 27%) and respiratory infections were also lower (23% versus 35%). We conclude that exclusive breastfeeding is superior at least until an infant is 6 months of age. To compare the growth and illness pattern of infants who were exclusively breast fed for six months with those of infants commenced on complementary feeding before the age of six months and ascertain reasons for the early introduction of complementary feeding.
                A comparative prospective study.
                Urban Comprehensive Health Centre (UCHC), Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife.
                Three hundred and fifty-two mothers and their normal birth weight babies, weighing 2.500kg or more, and aged less than 14 days were serially recruited into the study.
                Mean/median monthly weights in the first six months of life, history/outpatient presentation for illnesses.
                Of the 352 mother-infant pairs recruited into the study, 345 (98%) were successfully followed up for the first six months of life. At six months, 264 (76.5%) were exclusively breast-fed, 45 (13.1%) were started on complementary feeding, between the ages of four and six months while 36 (10.4%) commenced complementary feeding before the age of four months. Infants who were exclusively breast-fed for six months had median weights above the 50th percentiles of the WHO/NCHS reference that is currently used in the national "road to health" (growth monitoring) cards. Furthermore, the mean weight of these babies at age six months was above those of babies who started complementary foods before six months. They also reported fewer symptoms and had fewer illness episodes (0.1 episodes per child) compared to those who started complementary feeding before six months. Infants who commenced complementary feeding before four months reported more symptoms and had more illness episodes (1.4 episodes per child) compared to those that commenced complementary feeding between four and six months (1.2 episodes per child). Common symptoms/illnesses seen or reported during the study among the groups were fever, diarrhoea and cough. Reasons given for early introduction of complementary foods include insufficient breast milk, thirst and convenience.
                It is concluded that exclusive breast-feeding supported adequate growth during the first six months of life for most of the infants studied. Early introduction of complementary foods did not provide any advantages in terms of weight gain in our environment, it was frequently associated with illness episodes and growth faltering. Many mothers however require support, encouragement and access to health care providers to breastfeed exclusively for the first six months of life. Exclusive breastfeeding is recommended until age 6 months. We assessed the feasibility, effectiveness, and safety of an educational intervention to promote exclusive breastfeeding for this length of time in India.
                We developed the intervention through formative research, pair-matched eight communities on their baseline characteristics, and randomised one of each pair to receive the intervention and the other to no specific intervention. We trained health and nutrition workers in the intervention communities to counsel mothers for exclusive breastfeeding at multiple opportunities. We enrolled 1115 infants born in the 9 months after training-552 in the intervention and 473 in the control communities. Feeding at age 3 months, and anthropometry and of diarrhoea prevalence at age 3 months and 6 months were assessed. All analyses were by intention to treat.
                We assessed 483 and 412 individuals at 3 months in the intervention and control groups, respectively, and 468 and 412 at 6 months. At 3 months, exclusive breastfeeding rates were 79% (381) in the intervention and 48% (197) in the control communities (odds ratio 4.02, 95% CI 3.01-5.38, p<0.0001). The 7-day diarrhoea prevalence was lower in the intervention than in the control communities at 3 months (0.64, 0.44-0.95, p=0.028) and 6 months (0.85, 0.72-0.99, p=0.04). The mean weights and lengths, and the proportion with weight-for-height or height-for-age Z scores of 2 or less, at age 3 months and 6 months did not differ much between groups. Intervention effect on exclusive breastfeeding, diarrhoeal morbidity, and anthropometry at age 6 months in the low-birthweight subgroup was similar to that for all births.
                Promotion of exclusive breastfeeding until age 6 months in a developing country through existing primary health-care services is feasible, reduces the risk of diarrhoea, and does not lead to growth faltering. Exclusive breastfeeding, though better than other forms of infant feeding and associated with improved child survival, is uncommon. We assessed the HIV-1 transmission risks and survival associated with exclusive breastfeeding and other types of infant feeding.
                2722 HIV-infected and uninfected pregnant women attending antenatal clinics in KwaZulu Natal, South Africa (seven rural, one semiurban, and one urban), were enrolled into a non-randomised intervention cohort study. Infant feeding data were obtained every week from mothers, and blood samples from infants were taken monthly at clinics to establish HIV infection status. Kaplan-Meier analyses conditional on exclusive breastfeeding were used to estimate transmission risks at 6 weeks and 22 weeks of age, and Cox's proportional hazard was used to quantify associations with maternal and infant factors.
                1132 of 1372 (83%) infants born to HIV-infected mothers initiated exclusive breastfeeding from birth. Of 1276 infants with complete feeding data, median duration of cumulative exclusive breastfeeding was 159 days (first quartile [Q1] to third quartile [Q3], 122-174 days). 14.1% (95% CI 12.0-16.4) of exclusively breastfed infants were infected with HIV-1 by age 6 weeks and 19.5% (17.0-22.4) by 6 months; risk was significantly associated with maternal CD4-cell counts below 200 cells per muL (adjusted hazard ratio [HR] 3.79; 2.35-6.12) and birthweight less than 2500 g (1.81, 1.07-3.06). Kaplan-Meier estimated risk of acquisition of infection at 6 months of age was 4.04% (2.29-5.76). Breastfed infants who also received solids were significantly more likely to acquire infection than were exclusively breastfed children (HR 10.87, 1.51-78.00, p=0.018), as were infants who at 12 weeks received both breastmilk and formula milk (1.82, 0.98-3.36, p=0.057). Cumulative 3-month mortality in exclusively breastfed infants was 6.1% (4.74-7.92) versus 15.1% (7.63-28.73) in infants given replacement feeds (HR 2.06, 1.00-4.27, p=0.051).
                The association between mixed breastfeeding and increased HIV transmission risk, together with evidence that exclusive breastfeeding can be successfully supported in HIV-infected women, warrant revision of the present UNICEF, WHO, and UNAIDS infant feeding guidelines. In developing countries, the age at which breastfed infants are first given complementary foods is of public health importance because of the risk of diarrhoeal disease from contaminated weaning foods, and the potential risk of growth faltering if foods are inappropriately delayed. To evaluate whether there are any advantage of complementary feeding prior to 6 months, low-income primiparous mothers who had exclusively breastfed for 4 months were randomly assigned to one of 3 groups: continued exclusive breastfeeding to 6 months (EBF) (n = 50); introduction of complementary foods at 4 months with ad libitum nursing from 4-6 months (SF) (n = 47); and introduction of complementary foods at 4 months, with maintenance of baseline nursing frequency from 4-6 months (SF-M) (n = 44). Baby foods in jars were provided to the SF and SF-M groups from 4 to 6 months. Subjects were visited weekly and provided with lactation guidance; at 4, 5, and 6 months measurements were made of infant intake and breast milk composition. At 4 months, breast milk intake averaged 797 (139) g per day (no difference among groups). Between 4 and 6 months, breast milk intake was unchanged in EBF infants (+6) but decreased in the SF (-103), and SF-M (-62) groups (p < 0.001). Change in total energy intake (including solid foods) and infant weight and length gain did not differ significantly between groups. Weight and length gain from 4-6 months were comparable to those of breastfed infants in an affluent USA population. The results indicate that breastfed infants self-regulate their total energy intake when other foods are introduced. As a result, there is no advantage in introducing complementary foods before 6 months in this population, whereas there may be disadvantages if there is increased exposure to contaminated weaning foods. The objective of this study was to determine the exclusive breast-feeding practices, return of menstruation, sexual activity and contraceptive practices among breast-feeding mothers in the first six months of lactation. The study was based in Onitsha, South Eastern Nigeria. A structured questionnaire was used to obtain data from breast-feeding mothers on their age, educational attainment, breast-feeding practices, return of menstruation, sexual activity and contraceptive practices within the first six months of lactation at intervals of 6 weeks, 10 weeks 14 weeks and 6 months post delivery. Analysis of the information obtained showed that out of the 178 mothers who participated in the study 81% of the mothers were within the ages of 20 - 34 years. While all the mothers had formal education, the majority (59%) had secondary education. Seventy-three percent initiated breast-feeding within one hour of delivery. On discharge from hospital, all of them had already established breast-feeding which continued up to six weeks and dropped to 97.8% at six months. Exclusive breast-feeding which was practised by 100% on discharge dropped to 3.9% at six months. The feeding regimen was on demand as practised by 98.9% of the mothers. Menstrual flow had returned in 33.8% of the mothers by 6 weeks of lactation, and had risen to 70.2% at six months. There was more prolonged lactational amenorrheoa in exclusively breast-feeding mothers than in those who were not. By 6 weeks post delivery 31.6% of the mothers had resumed sexual activity and this rose to 93.6% at six months. With the resumption of sexual activity only 5% of the mothers resorted to contraceptive practices other than lactational amenorrhea and this increased to 54% at six months. There was no pregnancy in any of these women during the six months period. While appreciating the role of lactational amenorrhea in child spacing and considering the early return of sexual activity among the mothers the practice of introducing contraceptive practices needs to be encouraged especially in women whose menstruation has returned. We followed 183 infants for two years, 31 of whom were breast fed less than three and a half months (median 70 days; short breast feeding group) and a further 31 of whom were exclusively breast fed for more than nine months (long breast feeding group). We assessed heredity for atopy, number of infections, and duration of breast feeding as determinants of atopy. During the first year of life 14 infants has signs of atopy. During the second year parents reported signs of atopy in a further 31. Heredity was the only significant predictor of atopy. Atopy was seen in 33% of infants with a positive heredity and in 16% without family history for atopy. The duration of breast feeding affected the incidence of atopy only among the infants without family history for atopy: fewer in the short breast feeding group (1/18) had atopy than in the long breast feeding group (5/13). Duration of breast feeding did not associate with incidence of respiratory infections. Diarrhoea was more common in the short breast feeding group than in the long breast feeding group during the first year of life. We conclude that prolonging exclusive breast feeding from the median of 70 days to nine months did not contribute to the prevention of infantile atopy and respiratory tract infections. A randomized intervention trial to promote breast-feeding was carried out in southern Brazil. A group of 450 mothers and babies was visited at home 5, 10 and 20 days after birth and compared to a non-visited control group of the same size. Ninety-two per cent of the families visited received the three home visits planned. The evaluation of breast-feeding patterns and reasons for weaning took place 6 months after birth for both groups. Ninety-four per cent of the group visited and 92% of the non-visited controls group were traced on the occasion of the assessment. The intervention increased the duration of breast-feeding (median duration of 120 days in the group visited and 105 days in the controls; p = 0.03) and delayed the introduction of milk bottles (median age of introduction of 90 days in the group visited and 60 days in the controls; p = 0.01). Causes of weaning were classified as underlying, intermediate and immediate. The most common underlying cause of weaning was "the baby cried too much", which suggests that mothers should be taught about normal patterns of infant behaviour in the first weeks of life, particularly the need for crying, and the fact that this not necessarily reflects hunger. Long periods of exclusive as well as partial breast-feeding in poor communities are of considerable importance from a nutritional standpoint, as it is in these communities that malnutrition is predominant. Although benefits of exclusive breast feeding have been well documented, those for partial breast-feeding have not been examined. The present study in particular examines the effects of prolonged breast-feeding, i.e. exclusive breast-feeding beyond 6 months or partial breast-feeding up to 2-3 years, in terms of prevalent malnutrition and morbidity among rural children. A total of 395 children were observed for weight, height, information on duration of breast-feeding, age at weaning and morbidity in terms of recent illness in the 7 days prior to the day of visit. Exclusive breast-feeding beyond 6 months and up to 12 months appeared beneficial in terms of reduced morbidity. Beyond infancy, there was no evidence of any protective effect of partial breast-feeding. This could be due to poor lactational performance of mothers and their unawareness about it resulting in inadequate weaning foods being offered to partially breast-fed children. Significant differences in male and female children in the extent of malnutrition pointed towards discrimination against girls even in respect of exclusive breast-feeding. The study highlights the need for advocating proper weaning practices while recommending prolonged breast-feeding in poor communities. To determine whether an individualized, prenatal and postnatal, lactation consultant intervention resulted in increased cumulative intensity of breastfeeding up to 52 weeks.
                The randomized, nonblinded, controlled trial recruited women from prenatal care. Baseline prenatal interviews covered demographic data and breastfeeding experience, intention, and knowledge. Interviews at 1, 2, 3, 4, 6, 8, 10, and 12 months after birth collected data on weekly feeding patterns, infant illness, and infant health care use.
                Two community health centers serving low-income, primarily Hispanic and/or black women.
                The analytic sample included 304 women (intervention: n = 145; control: n = 159) with > or = 1 postnatal interview.
                Study lactation consultants attempted 2 prenatal meetings, a postpartum hospital visit, and/or home visits and telephone calls. Control subjects received the standard of care.
                Cumulative breastfeeding intensity at 13 and 52 weeks, based on self-reports of weekly feeding, on a 7-level scale.
                The intervention group was more likely to breastfeed through week 20 (53.0% vs 39.3%). Exclusive breastfeeding rates were low and did not differ according to group. In multivariate analyses, control subjects had lower breastfeeding intensity at 13 weeks (odds ratio [OR]: 1.90; 95% confidence interval [CI]: 1.13-3.20) and 52 weeks (OR: 2.50; 95% CI: 1.48-4.21). US-born control subjects had lowest breastfeeding intensity at 13 weeks (OR: 5.22; 95% CI: 2.43-11.22) and 52 weeks (OR: 5.25; 95% CI: 2.44-11.29). There were no significant differences in breastfeeding intensity among the US-born intervention, foreign-born intervention, and foreign-born control groups.
                This "best-practices" intervention was effective in increasing breastfeeding duration and intensity. Breastfeeding promotion should focus on US-born women and exclusive breastfeeding. Compared with preterm formula (PF), mother's milk (MM) is associated with lower rates of late-onset sepsis (LOS) and necrotizing enterocolitis (NEC) among premature infants. Because not all mothers of premature infants produce sufficient milk to supply their infants throughout hospitalization, we reasoned that pasteurized donor human milk (DM) would be a suitable alternative.
                Extremely premature infants (<30 weeks of gestation) whose mothers intended to breastfeed were assigned randomly to receive either pasteurized DM or PF if the supply of their own MM became insufficient during the study (birth to 90 days of age or hospital discharge). Infection-related events (LOS, NEC, meningitis, presumed sepsis, or urinary tract infection) that occurred after the attainment of a milk intake of 50 mL/kg, dietary intake, growth, skin-to-skin contact, and duration of hospital stay were compared. The primary analysis compared groups DM and PF on an intent-to-treat basis. If no differences were noted, then these groups were combined and compared with the reference group, group MM. If differences were noted, then the subsequent analyses compared each group with group MM.
                Of 243 infants, 70 (29%) received only MM; group DM included 81 infants and group PF included 92 infants. Because of poor weight gain, 17 infants (21%), all in group DM, were switched to PF. There were no differences in birth weight, gestational age, multiple births, and age at attainment of feeding of 50 mL/kg among groups. There were no differences between group DM and group PF in LOS and/or NEC, other infection-related events, hospital stay, or number of deaths. Group DM received a greater intake of milk and more nutritional supplements but had a slower rate of weight gain, compared with group PF. Compared with groups DM and PF, group MM had fewer episodes of LOS and/or NEC and total infection-related events and a shorter duration of hospital stay. Group MM also had fewer Gram-negative organisms isolated from blood cultures than did the other groups.
                In this randomized, blinded trial of feeding of extremely premature infants, we found that, as a substitute for MM, DM offered little observed short-term advantage over PF for feeding extremely premature infants. Advantages to an exclusive diet of MM were observed in terms of fewer infection-related events and shorter hospital stays. To determine if the addition of a multinutrient human milk fortifier to mother's milk while breastfeeding very preterm infants after hospital discharge is possible and whether it influences first-year growth.
                Of a cohort of 320 infants (gestational age: 24-32 weeks; birth weight: 535-2255 g), breastfed infants (65% [n = 207]) were randomly assigned shortly before hospital discharge to receive either unfortified (n = 102, group A) or fortified (n = 105, group B) mother's milk until 4 months' corrected age (CA). The remaining infants were bottle-fed with a preterm formula (group C). Follow-up was performed at term and at 2, 4, 6, and 12 months' CA.
                Mean duration of breastfeeding after term was not significantly different between groups A and B (11.8 and 10.6 weeks, respectively). Weight, length, and head circumference were not significantly different between groups A and B at 12 months' CA. Compared with groups A and B, infants in group C had a higher increase in weight z score until term and in length z score until 6 months' CA. At 12 months' CA, boys in group C were significantly longer and heavier compared with those in groups A and B, whereas girls in group C were longer and heavier compared with those in group A only. A higher protein intake was related to a higher serum urea nitrogen level and growth.
                Fortification of mother's milk after hospital discharge while breastfeeding very preterm infants was possible without influencing breastfeeding duration but did not significantly influence growth parameters at 1 year of age compared with unfortified mother's milk. To determine whether infants who are fed initially and advanced at 30 mL/kg per day (intervention) take fewer days to get to full feedings than those who are fed initially and advanced at 20 mL/kg per day (control), without increasing their incidence of feeding complications and necrotizing enterocolitis (NEC). We also examined whether these infants regain birth weight earlier, have fewer days of intravenous fluids, and a have shorter hospital stay.
                A randomized, controlled, single-center trial was conducted in a Neonatal Intensive Care Unit of a community-based county hospital in Houston, Texas. Infants between 1000 and 2000 g at birth, gestational age < or =35 weeks, and weight appropriate for gestational age were allocated randomly to feedings of expressed human milk or Enfamil formula starting and advanced at either 30 mL/kg per day or 20 mL/kg per day. Infants remained in the study until discharge or development of stage > or =IIA NEC.
                A total of 155 infants were enrolled: 72 infants in the intervention group and 83 in the control group. Infants in the intervention group achieved full-volume feedings sooner (7 vs 10 days, median), regained birth weight faster (11 vs 13 days, median), and had fewer days of intravenous fluids (6 vs 8 days, median). Three infants in the intervention group and 2 control infants developed NEC for an overall incidence of 3.2% (relative risk: 1.73; 95% confidence interval: 0.30-10.06).
                Among infants between 1000 and 2000 g at birth, starting and advancing feedings at 30 mL/kg per day seems to be a safe practice and results in fewer days to reach full-volume feedings than using 20 mL/kg per day. This intervention also leads to faster weight gain and fewer days of intravenous fluids. The influence of the breastfeeding pattern and several clinical variables upon the duration of postpartum amenorrhea was assessed in a group of healthy women selected for having had a normal pregnancy and delivery and being highly motivated for prolonged breastfeeding on demand. 676 women who were fully nursing at the second month postpartum entered the study. Supplements were administered to 11% and 48% of the infants by the end of the 3rd and 6th month, respectively. The first bleeding was experienced before the end of the sixth month postpartum by 57% of the cases. Supplementation had a strong negative influence while nursing frequency had a significant positive influence upon the length of amenorrhea. Notwithstanding, a frequency of 8+ suckling episodes per 24 h could not maintain amenorrhea in around half of the subjects. Age and parity had a moderate negative influence upon the risk of experiencing the first postpartum bleeding. Maternal weight and ponderal index, infant sex, birth weight and growth rate showed no significant influence upon the length of amenorrhea. In this urban population selected for having the highest motivation and best breastfeeding performance, the association of breastfeeding with amenorrhea was weak in comparison with what has been described for other populations. The risk of experiencing the first bleeding was reduced while fully breastfeeding with a high number of nursing episodes per day and night, particularly in older women with higher parity. But even in such situation 25% and 50% of the women had started to cycle by the end of the fifth and eight postpartum month.
Infants who are exclusively breastfed for six months experience less morbidity from gastrointestinal infection than those who are partially breastfed as of three or four months, and no deficits have been demonstrated in growth among infants from either developing or developed countries who are exclusively breastfed for six months or longer. Moreover, the mothers of such infants have more prolonged lactational amenorrhea. Although infants should still be managed individually so that insufficient growth or other adverse outcomes are not ignored and appropriate interventions are provided, the available evidence demonstrates no apparent risks in recommending, as a general policy, exclusive breastfeeding for the first six months of life in both developing and developed-country settings.