Robert T. Kambic

Evaluation of natural family planning programmes in Liberia and Zambia

Studies to evaluate use-effectiveness and cost-effectiveness of natural family planning (NFP) were conducted in Liberia and Zambia. The Liberian programme provided uni-purpose NFP services to 1055 clients mainly in rural areas; the Zambian programme provided NFP services integrated with MCH to 2709 clients predominantly in urban areas. The one-year life table continuation and unplanned pregnancy rates were 78.9 and 4.3 per 100 woman-years in Liberia, compared to 71.2 and 8.9 in Zambia. However, high rates of loss to follow-up mandate caution in interpretation of these results, especially in Zambia. More women progressed to autonomous NFP use in Liberia (58%) than in Zambia (35.3%). However, programme costs per couple-year protection were lower in Zambia (US

Natural family planning use-effectiveness and continuation

25.7) than in Liberia (US

Interobserver variation in estimation of day of conception intercourse using selected natural family planning charts

47.1). Costs per couple-year protection were higher during learning than autonomy, and declined over time. These studies suggest that NFP programmes can achieve acceptable use- and cost-effectiveness in Africa.

Factors related to autonomy and discontinuation of use of natural family planning for women in Liberia and Zambia

Numerous studies have been conducted to assess the use-effectiveness of natural family planning. However, because of imprecise definitions of terms, these studies show noncomparable results. Special effort is required to study natural family planning use-effectiveness by the same criteria as other family planning methods.

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

In order to study outcome of pregnancy related to timing of conception it is necessary to have both markers of ovulation and records of intercourse. Natural family planning (NFP) charts where the woman records basal body temperature (BBT) and mucus signs are ideal for this purpose. Much work has been done relating timing of BBT and mucus signs to ovulation, but very little work has been done to examine interobserver agreement on the interpretation of these signs. Four NFP experts examined 28 NFP pregnancy charts to determine the BBT rise, the mucus peak, and two most likely days of conception intercourse. The charts were selected because they provided difficulties in interpretation. The reviewers were able to agree on the most probable day of conception intercourse in 96.4% of cases, on the mucus peak in 74.1% of cases, and on the interval between the most probable conception intercourse and mucus peak in 70.4% of cases. There was poor agreement on the first day of the BBT rise (38.5%). The authors conclude that in selected difficult NFP charts, the mucus peak is a more valid indirect measure of ovulation both because it is subject to less interobserver variation and because it more closely approximates the timing of ovulation.

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

From 1983 to 1988, natural family planning programs were conducted in Liberia and Zambia. In Liberia 1055 and in Zambia 2709 women used natural family planning to avoid pregnancy. These users could become pregnant, discontinue use of the method, or become autonomous users. Women who changed intention did not stop use of natural family planning and were not treated as discontinuations. In a multivariate analysis, clients age, breastfeeding status, employment, urban/rural residence, time of registration in the program, and visit intensity were significantly associated with the outcomes. The most consistent association was that women who entered the programs in the later time periods were more likely to become autonomous users and less likely to discontinue use of the method or to experience an accidental pregnancy.

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

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.

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

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.

Sex ratio associated with timing of insemination and length of the follicular phase in planned and unplanned pregnancies during use of natural family planning.

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.

Timing of conception and the risk of spontaneous abortion among pregnancies occurring during the use of natural family planning

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.