Breast-feeding and post-partum amenorrhoea in Indonesia

The association between breast-feeding patterns and resumption of menses post-partum was examined in a prospective study in Indonesia. In order to examine these relationships directly in a longitudinal study, it was first necessary to distinguish among women who experienced infant mortality before menses resumed, women who weaned before menses resumed, and women who had return to menses while breast-feeding. Information on suckling patterns and menstrual status was collected by recall for 444 women at monthly visits for 2 years. Three main breast-feeding variables, minutes per episode, number of episodes per day, number of episodes per night, and other breast-feeding variables were derived for each woman, to give the average nursing pattern up to menses or the end of the study, which-ever came first. While high levels of nursing for each of these three main variables were found to be significantly related to delay in return of menses post-partum, the interactions between more minutes per episode, and more frequent day- and night-time feeds, were found to be the most important factors in the delay in onset of post-partum menstruation in those women whose menses resumed while still nursing or who remained amenorrhoeic and nursing at the end of the study.     

Measurement of post-partum amenorrhoea in Bangladesh.

Reported information on the duration of post-partum amenorrhoea usually shows considerable number preference, particularly at 6-monthly intervals. This paper presents a technique for smoothing such amenorrhoea data using a modified exponential curve. An attempt has also been made to estimate the average number of months a mother is expected to remain amenorrhoeic.     

Nutrition, infant feeding and post-partum amenorrhoea in rural Bangladesh

The extent to which differences in the duration of postpartum amenorrhea among chronically malnourished women in rural Bangladesh are related to seasonal patterns of food supply, maternal nutrition, education, and patterns of infant feeding was investigated by application of multivariate hazards models with time-varying covariates. The data were derived from the Birth Interval Dynamics study in Matlab and covered close to 1800 births. Parity, education, season of birth, maternal weight, and infant supplementation all were found to affect the duration of postpartum amenorrhea among these women. Education of 5 or more years had a positive effect on the resumption of menses. Higher parity women, who were older, had longer periods of amenorrhea, as did women who gave birth in October-December. As a measure of nutritional status, the woman's weight at pregnancy termination showed a highly significant positive coefficient, indicating that improved maternal nutrition increased the likelihood of resuming menstruation. Food supplementation, which tends to decrease breastfeeding, also significantly increased the risk of resuming menstruation and had an effect independent of the other variables. When the data were analyzed by season, the most striking finding was the strong influence of education on children born during October-December (who are too young to be directly affected by the larger food supply at birth during the harvest season). The other seasons showed weaker effects of education and a stronger effect of supplementation, perhaps because these infants are older during the harvest season and thus can benefit from supplements.     

Extending lactational amenorrhoea in Manila: a successful breast-feeding education programme.

An experimental breast-feeding education programme conducted at the Philippine General Hospital in Manila demonstrated that women could be motivated to improve their breast-feeding practices and lengthen their period of lactational amenorrhoea in comparison to a control group. Mothers who participated in the programme breast-fed their babies more frequently, delayed the introduction of regular supplements, used fewer bottles and pacifiers and maintained night feeding longer than mothers who were not exposed to the positive breast-feeding messages. The programme was successful in lengthening the period of amenorrhoea among women with elementary, high school, or technical school education, but not among college-educated women. Different educational approaches may be necessary for women of different education levels.     

Nursing behaviour and its relation to duration of post-partum amenorrhoea in an Andean community

Nu?oa is a high altitude rural Peruvian community characterized by socioeconomic stratification and differential access to the market economy. Nursing practices and the effects of nursing are also stratified; this translates into a risk of menses at 12 months post-partum nearly seven times greater in wealthier than in poorer women. Most nursing occurs in the morning, among those who practice on-demand breast-feeding. Nursing episodes are clustered into sessions; the amount of breast-feeding is regulated by varying the number of episodes per session rather than by changing the duration of suckling episodes or the frequency of sessions per hour. Thus, resumption of ovulation is not dependent on the variable spacing of nursing episodes or sessions. The components of nursing activity most likely to be responsible for variation in the duration of post-partum amenorrhoea in these nursing women are mean session duration and mean number of episodes per session. The mean duration of morning nursing sessions is negatively associated with infant's age, reflecting the greater reliance of younger children on breast-milk. The mean duration of afternoon nursing sessions is positively associated with mother's age, independent of infant's age, possibly reflecting maternal age-related variation in milk production capabilities. Baby minding by older daughters may also help to explain variation in afternoon nursing.     

Analysis of postpartum lactational amenorrhoea in relation to breast-feeding: some methodological and practical aspects.

A large multicentre epidemiological study was carried out by WHO between 1991 and 1995 to analyse the duration of lactational amenorrhoea in relation to breast-feeding. The main results of this analysis, which used classical statistical modelling, have been already published. However, some specific aspects of the postpartum fertility amenorrhoea and breast-feeding covariates, and more specifically the observed progressive exhaustion of the breast-feeding inhibitory effect on the reproductive axis, may justify a closer look at the validity of the statistical tools. Indeed, as has already been emphasized, analysis of large longitudinal data sets in reproduction often faces three difficulties: (i) the precise determination of the event of interest, (ii) the way to handle the time evolution of both the studied variables and their effect on the event of interest and (iii) the often discrete nature of the data and the associated problem of tied events. The first objective of the present work was to give additional insights into the estimation and quantification of the dynamics of the effect of breast-feeding over time, considering this covariate either as fixed or time-dependent. The second objective was to show how to perform the analyses using corresponding adapted procedures in widely available statistical packages, without the need for acquiring particular programming skills.     

Radioiodine fallout and breast-feeding

The rationale for suspension of breast-feeding after exposure to radioiodine in fallout is presented.     

Investigation and treatment of amenorrhoea resulting in normal fertility.

A simple scheme of investigation and treatment to restore fertility in amenorrhoeic women is described. Fifty-nine patients with amenorrhoea not due to primary ovarian failure were treated variously as appropriate, mainly with clomiphene (25), bromocriptine (15), or human menopausal gonadotrophins (12), and six by diet to increase their weight. All ovulated, and by the end of the study 55 (93%) had conceived, 42 (71%) had delivered at least one surviving child, and five others (8%) were pregnant and awaiting delivery. Conception rates were 49% within two cycles of treatment and 66% within three cycles; using life-table method to standardise the cumulative conception rates by correcting for patients who did not continue as long as others in the study, the expected conception rate was 79% in six cycles, 94% in 12 cycles, and 98% after 16 cycles. The multiple pregnancy rate was 13% and abortion rate 22%. Delivery rate (for a viable baby) were 48% within 11 months of starting treatment and 53% within one year; expected rates were 76% in 18 months and 97% in two years. The results show that a relatively simple scheme of classifying amenorrhoeic disorders endocrinologically followed by treatment directed at inducing ovulation allows amenorrhoeic women without primary ovarian failure to achieve conception and delivery rates equal to those in normal women.     

Prevalence and duration of breast-feeding in Manitoba.

The rate of breast-feeding in the first 3 months post partum was studied in a group of 456 mothers. At 3 months 58% had been or still were breast-feeding their infants. The mothers who breast-fed were older, had a higher level of education, had a higher socioeconomic status, and were more likely to live on farms or in small towns, to have attended prenatal education classes and to have previously breast-feds. There were no significant differences between the method of feeding and the sex or birthweight of the infant, the maternal weight/height ratio or the participation of the father in the prenatal education classes. At 1 month 45% of the infants, at 2 months 35% and at 3 months 28% were being breast-fed. Public programs to promote breast-feeding as normal, beneficial and satisfying to both mother and infant are necessary so that more mothers will attempt to breast-feed their infants. Support for continuance of breast-feeding is needed in the hospital as well as in the home and the community.     

Raised serum prolactin levels in amenorrhoea.

Serum prolactin levels measured by specific radio-immunoassay were over 30 mug/l in seven out of 25 women with amenorrhoea and in eight women with the amenorrhoe-galactorrhoea syndrome. There was no apparent relationship between these levels and levels of follicle-stimulating hormone, luteinizing hormones, and thyroid-stimulating hormone. Bromocriptine caused a transient fall in the proclatin levels in six out of seven cases, and in three menstruation and ovulation were restored. Estimation of serum prolactin may become important in assessing the degree of hypothalamic-pituitary dysfunction in amenorrhoea, and it may help in identifying a subgroup of patients at risk of developing a pituitary tumour or patients who may respond to specific treatment.     

Estimation of births averted due to breast-feeding and increases in levels of contraception needed to substitute for breast-feeding

After contraceptive use, breast-feeding duration is the major determinant of the birth interval length. Three methods of estimating births averted by breast-feeding, and the increase in contraceptive use needed to substitute for breast-feeding, are presented. Method 1 simply utilizes Bongaarts' Ci, and the other two are based on mean birth intervals with and without breast-feeding. Estimates for each method are derived for six countries with DHS surveys from the mid-1990s: Burkina Faso, Uganda, India, Indonesia, Brazil and Peru. The estimated percentage of additional births that would occur if there were no breast-feeding ranged from 1-4%, in Brazil to about 50% in Burkina Faso and Uganda, reflecting very low breast-feeding in Brazil and very high levels in the sub-Saharan African nations. Strengths and limitations of the three methods are considered.     

The duration of lactational amenorrhoea in urban Bangladeshi women

The duration of lactational amenorrhoea, and infant feeding patterns and behaviour, were investigated in a sample of 97 mother-infant pairs living in a poor urban area of Dhaka, Bangladesh. A seven-hour time allocation method was used to determine the number of breast-feeding bouts and their duration. The seven-hour observation period was conducted on five occasions: at birth, 1 month, 4 months, 8 months and either 10 or 11 months. The median duration of lactational amenorrhoea was determined to be 24.07 weeks using survival analysis. Mothers who breast-fed their babies for longer and more frequently had, on average, a longer period of lactational amenorrhoea. There was no relationship between sociodemographic characteristics of the mother and duration of lactational amenorrhoea, nor was there any significant relationship between maternal anthropometry and birth weight of the baby and duration of lactational amenorrhoea, but there was a tendency for women with lower body mass index to have longer durations. Using the Cox proportional hazards model, the best predictor of duration of lactational amenorrhoea was the mean of months 0 and 1 durations of breast-feeding, adjusted for the mean frequencies for those months. The introduction of weaning food was also an important predictor.