Alfredo Perez

Clinical study of the lactational amenorrhoea method for family planning

The effect of breastfeeding on fertility is well known; however, its use as a method of family planning was, until recently, untested. In 1988, the Bellagio Consensus Conference proposed guidelines that became the basis for a method of family planning called the lactational amenorrhoea method (LAM). The principle of LAM is that a woman who continues to fully or nearly fully breastfeed her infant and who remains amenorrhoeic during the first 6 months postpartum is protected from pregnancy during that time. We have assessed this method in the context of a breastfeeding support intervention study of 422 middle-class women in urban Santiago, Chile. The cumulative 6-month life-table pregnancy rate was 0.45% among women who relied on LAM as their only family planning method (1 woman pregnant in month 6). The findings indicate that LAM, with its high acceptance and efficacy, is a viable method of family planning and can safely serve as an introductory method for breastfeeding women.

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.

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.

Santiago Breastfeeding Promotion Program: preliminary results of an intervention study.

A prospective intervention study was undertaken in Santiago, Chile, to assess the impact of a breastfeeding promotion program and the acceptance and use of the lactational amenorrhea method for natural child spacing. The intervention study significantly increased the duration of exclusive breastfeeding and amenorrhea. In addition, the use of the lactational amenorrhea method proved highly efficacious, with an unplanned pregnancy rate of less than 0.5% by 6-month cumulative life table. Total family planning coverage at 6 months was increased in the intervention group.

Use-effectiveness of the ovulation method initiated during postpartum breastfeeding

Between April 1981 to March 1984, 419 urban middle class postpartum women entered the Natural Family Planning (NFP) program of the Pontificia Universidad Catolica de Chile. This NFP program teaches the Ovulation Method (Billings). Only 1.9% of the women did not learn how to recognize the mucus pattern of fertility awareness. The sample of 378 women who were practicing the method to avoid a pregnancy completed 4,935 months of use of the OM. The cumulative life table unplanned pregnancy rate at the 12th postpartum month was 11.1 +/- 1.9 and the Pearl Rate was 12.1 per 100 woman-years. The Pearl Rate calculation of method-related failure was only 2.1 pregnancies per 100 woman-years. The breastfeeding group showed a significantly lower rate of unplanned pregnancies than the nonbreastfeeding group and there was no significant increase in unplanned pregnancy at the time of menstruation among previously amenorrheic women as compared to later intervals. The protection against unplanned pregnancy shown in this study should be viewed as the combination of two factors: breastfeeding and the Ovulation Method (OM) of NFP.

Efficacy studies in natural family planning: Issues and management implications illustrated with data from five studies

Studies of method effectiveness must be carefully assessed for comparability of findings. Several parameters are identified that are important in the assurance of comparable results. This article discusses these issues with the use of data from previously published studies and emphasizes the management implications of use-effectiveness data.

Fertilisation involving ageing gametes, major birth defects, and Down's syndrome.

For many years, ageing of gametes as a result of prolonged retention in the female reproductive tract before fertilisation has been circumstantially associated with major birth defects. To assess this association, we studied pregnant women who had recorded the timing, with regard to presumed ovulation, of the coital event leading to conception. We found major anomalies in 11 (2.7%) of 400 infants born to women with optimally timed conceptions (on the day of or 1 day before ovulation), compared with 14 (2.5%) of 538 infants of women with non-optimally timed conceptions (odds ratio 0.94, 95% CI 0.43-2.06). The numbers of infants with Downs syndrome were two (0.5%) of 400, and four (0.7%) of 538, respectively (1.48, 0.27-8.06). There is no association between ageing gametes and major birth defects, including Downs syndrome.

Pregnancy outcome in natural family planning users: cohort and case-control studies evaluating safety

Conceptions involving aging gametes are of relevance to natural family planning (NFP) because women using NFP to avoid pregnancy abstain from intercourse during the fertile time of the cycle. To help verify the safety of pregnancies occurring among NFP practitioners, our group has, since 1986, conducted a large cohort study involving six experienced NFP centers. Timing of conception was determined from NFP charts, in which women recorded days on which intercourse occurred. The number of days from the most probable conception intercourse to probable day of ovulation was first determined, and used as an estimate of the time gametes remained in the genital tract before fertilization. Several studies have already been completed, cohort as well as case-control in nature.1. Spontaneous abortions. Three hundred and sixty-one conceptions occurred during the optimal time (day -1 or 0 relative to ovulation), and of these 33 resulted in spontaneous abortion (9.1%). Five hundred and seven conceptions occurred at non-optimal times during the cycle, and of these 55 resulted in spontaneous abortions (10.9%). These differences were not statistically significant (relative risk 1.19, 95% CI, 0.79-1.80) [1].2. Anomalies. Among 780 singleton births in 868 cohort pregnancies, 24 infants had major anomalies (3.1%) as of the present analysis [2]. This frequency is comparable to the general population. To further assess anomalies we employed a case-control approach. All consecutive births (live and stillborn) weighing 500 g or more taking place in 18 participating South American hospitals were examined for minor and major congential anomalies. Mothers of malformed and control infants did not differ with respect to the reported frequency of NFP use, which overall was 6.3% of the 10 642 mothers interviewed (5277 having a malformed infant; 5371 controls). Of 262 discordant pairs, there were 28 or 10.69% mothers within the Down syndrome case group vs. 16/262 or 6.11% among matched controls [3,4]. The odds ratio was 1.84; 95% CI, 0.99-3.96; however, even this non-significant difference narrowed substantially when adjusted for maternal age (OR, 1.78; 95% CI, 0.84-3.75); parity (OR, 1.68; 95% CI, 0.87-3.24); maternal educational level (OR, 1.71; 95% CI, 0.86-3.44); or all three together (OR, 1.74; 95% CI, 0.83-3.64).Conclusions. Our findings should be reassuring to natural family planning users. The overall rate of spontaneous abortion was not increased in NFP users who became pregnant, nor to date was the rate of anomalies. Any contribution to Down syndrome or abortion due to aging gametes would have to be small.

Risk of recurrent spontaneous abortion for pregnancies discovered in the fifth week of gestation

3 Wood DA, Riemersma RA, Butler S, Thomson M, Macintyre C, Elton RA. Linoleic and eicosapentaenoic acids in adipose tissue and platelets and risk of coronary heart disease. Lancet 1987; i: 177-82. 4 Katan MB, Van de Bocenkamp P. Eicopentaenoic acid in fat. Lancet 1987; i: 862-63. 5 Riemersma RA, Wood DA, Butler S, et al. Linoleic acid content in adipose tissue and coronary heart disease. BMJ 1986; 292: 1423-27.

Effects of timing of conception on birth weight and preterm delivery of natural family planning users.

Objective: Various birth defects and untoward perinatal outcomes have been claimed to be associated with pregnancies conceived by gametes aged in vivo before fertilization. Thus, these outcomes were systematically assessed in pregnancies occurring in natural family planning (NFP) users. Our international multicenter cohort study of NFP pregnancies (n = 877) is by far the largest systematic study designed to assess pregnancy outcome and is of sufficient power to allow us to address the concern of low birth weight (< 2500 g) and preterm delivery (< 37 weeks gestation).Study design: In addition to gathering baseline medical data, evaluation was performed at 16 weeks, 32 weeks and at term. Data were collected in a systematic cohort fashion, verified by the five collaborating international recruiting centers, and analyzed by investigators in the US. Most recruiting center principal investigators are obstetrician-gynecologists and, if not, have integral relationships with such specialists. Standard criteria could thus be applied within and among centers. In our cohort, birth weight was recorded accurately at delivery. Almost all of the deliveries occurred in hospitals; thus, data should be quite reliable. Neonatal examination for anomalies was usually conducted immediately after delivery, when birth weight was recorded.Results: Analysis of risk factors for low birth weight and pretern delivery showed that this population had a low risk profile. Low birth weight infants (< 2500 g) and preterm deliveries were increased among women with a history of either prior low birth weight or preeclampsia in the index pregnancy. However, mean birth weight was unaffected by the timing of conception vis à vis ovulation or pregnancy history. Mean birh weight for the 877 singleton NFP pregnancies was 3349.6 g. The risk of preterm delivery was increased among older women who drank alcohol, but there were no significant effects of timing of conception vis à vis ovulation on preterm delivery. Results held when analysis was stratified according to whether NFP was being used for contraception or to achieve pregnancy.Conclusions: Our data do not appear to show striking differences between 877 NFP pregnancies and the general obstetric population. The timing of conception vis à vis ovulation does not exert significant effects on the birth weight or preterm delivery of resulting pregnancies, a reassuring finding for NFP users.