Time to pregnancy: results of the German prospective study and impact on the management of infertility

Abstract

BACKGROUND: The likelihood of spontaneous conception in subsequent cycles is important for a balanced management of infertility. Previous studies on time to pregnancy are mostly retrospective and biased because of exclusion of truly infertile couples. The study aim was to present a non-parametric estimation of cumulative probabilities of conception (CPC) in natural family planning (NFP) users illustrating an ideal of human fertility potential. METHODS: A total of 346 women was observed who used NFP methods to conceive from their ®rst cycle onwards. The couples practising NFP make optimal use of their fertility potential by timed intercourse. The CPC were estimated for the total group and for couples who ®nally conceived by calculating Kaplan-Meier survival rates. RESULTS: A total of 310 pregnancies occurred among the 346 women; the remaining 36 women (10.4%) did not conceive. Estimated CPC for the total group (n = 340 women) at one, three, six and 12 cycle(s) were 38, 68, 81 and 92% respectively. For those who ®nally conceived (truly fertile couples, n = 304 women), the respective pregnancy rates were 42, 75, 88 and 98% respectively. Although the numbers of couples in both groups were similar, the impact of age on time to conception, as judged by the Wilcoxon test, was less in the truly fertile than in the total group. CONCLUSIONS: Most couples conceive within six cycles with timed intercourse. Thereafter, every second couple is probably either subfertile or infertile. CPC decline with age because heterogeneity in fecundity increases. In the subgroup of truly fertile couples, an age-dependent decline in CPC is statistically less obvious because of high homogeneity, even with advancing age.

Efficacy of Achieving Pregnancy with Fertility-Focused Intercourse

“…Our findings were consistent with previous studies that involved focusing intercourse during the selfestimated fertile window with the use of natural indicators of fertility (Hilgers, Daly, Prebil, & Hilgers, 1992;Gnoth et al, 2003;. All these studies highlighted the importance of focused intercourse within the fertile window.…”

“…The pregnancy rate declines reversely as time goes on. This indicates that for women with normal fertility, timed intercourse usually leads to successful pregnancy within six months (Gnoth et al, 2003). We recommend that fertility charting and targeted intercourse with high and peak fertility should be utilized as the first line of fertility evaluation and intervention to help women to achieve pregnancy.…”

Pilot Evaluation of an Internet‐Based Natural Family Planning Education and Service Program

“…Hilgers, Daly, Prebil, and Hilgers (1992) reported a study in which 49 of 50 couples of normal fertility achieved a pregnancy within 5 months by focusing intercourse on days of good quality cervical mucus. German researchers reported the largest prospective study to estimate the cumulative probabilities of conception among a cohort of 346 couples using the symptom-thermal method (i.e., cervical mucus and basal body temperature monitoring) from their ¢rst cycle onwards (Gnoth, Godehardt, Godehardt, Frank-Herrmann, & Freundl, 2003). There were a total of 310 pregnancies among the 346 couples during a maximum of 29 cycles of observation.…”

Perinatal attachment in naturally pregnant and infertility-treated pregnant women in Taiwan

“…Keywords: infertility treatment, maternal-foetal attachment, maternal-infant attachment, nurses, questionnaire survey Introduction Infertility is one of life's great catastrophes, and it is a problem for approximately one in ten couples (Gnoth et al 2003). Infertility not only affects reproductive capacity but also causes some mental and social issues (Chang & Kuo 2000, Williams et al 2007).…”