Plasma prolactin/oestradiol ratio at 38 weeks gestation predicts the duration of lactational amenorrhoea

BACKGROUND

Fully breastfeeding women experience an amenorrhoea of variable duration. Our aim was to identify in pregnancy, endocrine markers that could predict the duration of subsequent lactational amenorrhoea.

METHODS

We studied 17 healthy women at 34 and 38 weeks gestation, and 1 and 3 months post-partum. The women fully breastfed until 6 months post-partum. During pregnancy, prolactin (PRL), oestrogens (total oestradiol, unconjugated oestrone, unconjugated oestriol), sex hormone binding globulin (SHBG), dehydroepiandrosterone sulphate (DHEA-S), progesterone and placental lactogen, and during post-partum PRL, oestrogens and SHBG, were measured. Free oestradiol in pregnancy and post-partum was calculated.

RESULTS

Ten women experienced long (>6 months) and seven experienced short (<6 months) lactational amenorrhoea. At 38 weeks gestation, the women who experienced a long lactational amenorrhoea had twice as much PRL, about half the total oestradiol, lower SHBG concentration (P < 0.05, Student's t-test, Bonferroni modification) and similar free oestradiol concentration, compared with those who experienced short lactational amenorrhoea. The difference in PRL concentration persisted in post-partum postsuckling samples.

CONCLUSION

At 38 weeks gestation, the ratio PRL/oestradiol identified all individual women according to the subsequent duration of their lactational amenorrhoea, suggesting that duration of lactational amenorrhoea is conditioned during pregnancy.

The efficacy of the lactational amenorrhea method (LAM) among working women

The purpose of this study was to assess the efficacy of the lactational amenorrhea method (LAM) for family planning among mothers who are separated from their infants by work. The study population, 170 urban middle class women who planned to return to work before 120 days postpartum, were interviewed monthly for 6 months postpartum and contacted at 12 months. The study population received clinical support for expressing their milk and exclusively breast-milk feeding the infants and for the use of LAM for birth spacing. The cumulative life table pregnancy rate by 6-month was 5.2%, with 3 pregnancies, one at each of months 4, 5, and 6. LAM for working women, as described in this article, might be associated with a higher pregnancy risk than LAM use among non-working women. Therefore, women using LAM should be informed that separation from the infant might increase their risk of pregnancy.

Clinical support can make the difference in exclusive breastfeeding success among working women

Exclusive breastfeeding has generally been considered incompatible with working separated from the infant. This prospective, controlled intervention trial shows that breastfeeding support, including anticipatory counseling and monthly clinical follow-up of the mother and infant, can significantly increase the percentage of infants exclusively fed with breastmilk at the end of 6 months of life. Over 80 per cent of women from control and intervention groups expressed a desire to breastfeed for more than 6 months and more than 50 per cent thought it was best for the infant to be exclusively breastfed for 6 months. Only 6 per cent of women in the control group were able to complete 6 months of exclusive breastmilk feeding compared to 53 per cent of those in the intervention group. The most important difference between the strategies used by both groups of mothers for maintaining exclusive breastmilk feeding after returning to work was that only 23 per cent of the control group practiced milk expression compared to 66 per cent in the intervention group. All women from the supported group stated that they would advise a friend to combine exclusive breastfeeding and work and that they would like to do so again with another child.

Does prenatal breastfeeding skills group education increase the effectiveness of a comprehensive breastfeeding promotion program?

A control/intervention study carried out in Santiago, Chile assessed the impact of five interventions on breastfeeding patterns and duration, and demonstrated a significant increase in full breastfeeding at six months (32 percent to 67 percent). Fifty-nine of 422 post-intervention women were included in a sixth intervention: prenatal group educational sessions emphasizing the skills necessary to initiate and maintain breastfeeding past the neonatal period. A significantly higher percentage of this subset of women were fully breastfeeding at six months compared to those who received only the five basic interventions (80 percent and 65 percent, respectively). The effect was greater among primiparous women. We conclude that prenatal group education with hands-on skills reinforcement is a significant and additive component of breastfeeding support, especially among those who have no previous breastfeeding experience.

The effects on professional practices of a three-day course on breastfeeding

This study assessed reported changes in clinical breastfeeding support practices following a three-day (approximately 24 hour) course. The course, presented at the Catholic University in Santiago, Chile, included the physiology of lactation and lactational infertility, related policy, clinical skills, the Lactational Amenorrhea Method (LAM), and program-related findings. A questionnaire was sent to all participants and an additional systematic sample was telephoned to assure a statistically valid sample. Sixty-nine percent of respondents reported changes in clinical practices resulting from attendance at the course. The results support the concept, now being advanced by the Baby-Friendly Hospital Initiative, that an 18-24 hour course can change clinical practices.

The impact of a hospital and clinic-based breastfeeding promotion programme in a middle class urban environment

Hospital interventions in support of breastfeeding have been highly successful in areas where the indigenous population has a well established environment of breastfeeding. However, programmes designed to improve breastfeeding patterns in urban populations have met with mixed success. This paper presents a prospective intervention study with a control group in which a health system-based breastfeeding promotion programme was initiated to support optimal breastfeeding for both child health and child spacing. Following collection of control data, a four-step intervention programme (Breastfeeding Promotion Program) was instituted. This paper reports the process of the development of the intervention programme as well as the comparison of the control and study populations. Major findings include significant increases in duration of full breastfeeding from 31.6 per cent at 6 months in the control group to 66.8 per cent in the intervention group. The duration of lactational amenorrhea was similarly increased: 22 per cent of the control mothers and 56 per cent of the intervention group women were in amenorrhoea at 180 days. The cost-effectiveness of the hospital changes is illustrated.