Almost 3 in 10 women conceive naturally within six years after IVF treatment regardless of the outcome of their previous infertility treatment

Silhouette_pregnant_couple_840x1024In a study recently published in Human Fertility it was shown that almost 3 in 10 women (29%) who had received infertility treatments (IVF/ICSI) did conceive spontaneously  within 6 years of the cessation of treatments. In the study performed by Marcus et al., the objective was to determine whether women who had gone through IVF treatment could become pregnant “naturally” when they were no longer actively treated; how long would it take and what factors were associated with conception? Two separate outcomes were investigated: (1) spontaneous pregnancies following discontinuation of IVF/ICSI treatment and (2) live birth following spontaneous pregnancies. It was demonstrated that 87% of the spontaneous conceptions occurred within 2 years of finishing the infertility treatments and over the 6-year period following IVF/ICSI treatments 22% resulted in a live baby.

Internet Survey.  The study was designed from an internet-based survey where all registered users of an independent infertility website (www.ivf-infertility.com) were asked to participate anonymously. The questionnaire addressed issues relating to the duration and cause of infertility, number of IVF/ICSI cycles and outcome, whether they conceived following discontinuation of the IVF treatment and if so, how long after discontinuation and what was the outcome. Spontaneous conception rates between women who had successful IVF/ICSI outcome and those who did not were not compared since the time to conceive varied between the two groups.

Who participated in the study?  484 users responded to the questionnaire. 39% of the couples received their treatment in the UK and the remainder overseas. The majority (42%) of the women were between 30 and 34 years old. Out of the 484 who responded, 403 met the criteria for inclusion of the study. These 403 patients underwent 1065 IVF/ICSI treatment cycles in total (2.6 cycles per patient) where 307 conceived by IVF/ICSI and 253 resulted in live births.

peeonastickHow many of the women became pregnant spontaneously after discontinuation of the IVF treatments?  In total, 29% (118 of the 403 women in the study) conceived spontaneously following cessation of IVF/ICSI treatments regardless of the outcome of their previous IVF/ICSI and 99 of them had live births. When dividing these women in to two groups, one that conceived during IVF/ICSI treatment (307 women) and one that did not (96 women), the study showed that 27% (84 out of 307) of the women who had become pregnant during their infertility treatment also spontaneously conceived after the discontinuation of their treatment and 22% (69 women) had live births. In the group of women who had not conceived during their IVF/ICSI treatment, 35% (34 out of 96 women) did conceive spontaneously after their treatments were discontinued and 31% (30 women) had live births. See figure 1 below.

Figure 1 Marcus et al, Human Fert 2016

How long time before spontaneous conception following discontinuation of IVF/ICSI? The majority (87%) of the women who conceived spontaneously after IVF/ICSI did so within 2 years of discontinuing treatment, 10% conceived within 3–4 years, 2% conceived within 5–6 years and only 1% conceived 6 years after discontinuation of treatment.

Different outcomes depending on different factors.  No matter if a couple is fertile or struggle with infertility, there are different factors associated with if and how that couple will be able to conceive. In case of infertility, there are additional factors that will negatively affect the chance of having a healthy baby. Here, in this study the authors showed that different types of infertility diagnosis as well as the number of IVF cycles and the duration of infertility before initiating infertility treatment were associated with the ability to spontaneously conceive after discontinuation of IVF/ICSI treatment. Depending on what factors the couples were struggling with, the outcome would differ. So who, according to this study, is more likely to conceive naturally following cessation of infertility treatment?

Unexplained infertility:  This study showed that unexplained infertility was associated with the highest chance of spontaneous conception compared with other causes of infertility.

Ovulation problems:  In total, 42 of the 403 women in the study suffered from ovulation problems. 36 of them had successful IVF/ICSI treatments and out of these women 14 also conceived spontaneously when the treatment was ended. Of the 22 women who did not conceive 11 had further infertility treatments (ovulation induction) after the IVF/ICSI treatment was over and 7 of these women conceived and had live births.

Tubal blockage: 13% (52 out of the 403) of the women in the study were diagnosed with tubal blockage or damage. 40 of them were suffering from bilateral tubal blockage (both fallopian tubes were non-functional) but 28 were able to conceive during IVF/ICSI treatment. Interestingly 7 of these 28 women also conceived spontaneously after cessation of treatment. However, only 2 of these 7 women had live births whereas the remainder were two ectopic pregnancies, two miscarriages and one medical termination of pregnancy. Out of the 12 women with bilateral tubal blockage/damage who did not conceive during their IVF/ICSI treatment, 2 did spontaneously conceive after discontinuation of the treatment and they both had live births.

Endometriosis: 11% (48 of 403) of the women in the study had endometriosis. The majority of them (40) had successful IVF/ICSI treatments resulting in conception and 14 of these 40 women also conceived spontaneously after discontinuation of the treatment. None of the eight women who did not conceive by IVF/ICSI had a spontaneous conception.

Male factor infertility: 20% (81 out of the 403 couples) in the study were diagnosed with male factor infertility. 15% (9 of the 61) who conceived by ICSI conceived spontaneously following cessation of ICSI and 8 of them had live births. 30% (6 out of 20) who failed to conceive by ICSI conceived spontaneously and 5 of them had live births.

Number of IVF/ICSI treatment cycles: Women who had 4 or less treatment cycles had higher chances of spontaneous conception than women who had more than 4 cycles of IVF/ICSI.

Duration of infertility prior to IVF treatment. In this study it was also demonstrated that a shorter duration of infertility (<4 years) prior to embarking on IVF/ICSI treatment was positively associated with spontaneous conception after cessation of the treatment.

Summary – Who is more likely to conceive following discontinuation of the treatment?  Marcus et al showed that unexplained infertility and ovulation problems were strongly associated with conception and live birth. However, spontaneous conception was lower for couples where the man was suffering from male factor infertility and in couples where the woman was diagnosed with bilateral tubal damage. Couples who had tried for less than 4 years before IVF/ICSI treatment had a higher chance to conceive spontaneously compared to couples with a longer duration of infertility. The number of IVF/ICSI cycles were also shown to be important where 4 or less IVF/ICSI cycles were positively associated with spontaneous conception compared to those who had more than 4 cycles.

Strengths and limitations of the study. There are of course limitation to this study, and one is the lack of a true response rate and therefore the possibility of selection bias should not be excluded. The study was retrospective and relied on patient’s self-reporting. Pregnant couples may have been more likely to participate in the study than disappointed couples. However, this study compared with many previous studies was not restricted to a specific population cohort, treatment, or age, or duration of follow up. Furthermore, the authors were attempted to rule out cofounding factors. Additionally, the study analyzed the cumulative live birth in women who were conceived by IVF/ICSI treatments but who failed to achieve a live birth.

The silhouette picture was borrowed from: http://www.owletcare.com/blog/pregnancy-myths-true-or-false

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