Implications of Blood Type for Ovarian Reserve
Implications of Blood Type for Ovarian Reserve
Background: We explored the relevance of blood type to ovarian reserve, as reflected by early follicular phase FSH levels.
Methods: For this cross-sectional observational study, early follicular phase serum levels of FSH (mIU/ml) and estradiol (E2, pg/ml), and information on blood type (A, B, AB and O) and patient age were procured for female patients, ≤45 years age (n= 544), who were undergoing fertility evaluation at one of two tertiary care facilities. Serum FSH > 10 mIU/ml was taken to reflect diminished ovarian reserve (DOR). Data distribution for FSH and age was analyzed and non-parametric tests used for comparisons across blood groups. Multivariable logistic regression analyses determined the relationship between elevated FSH and respective blood types after adjusting for age and study site.
Results: Prevalence of blood types according to order of frequency was: O (45%), A (35%), B (16%) and AB (5%). After adjusting for age and study site, patients with blood type O were twice as likely to exhibit FSH > 10 mIU/ml compared with those with A or AB blood types [odds ratio (OR) 2.36; 95% confidence interval (CI) 1.27–4.41; P= 0.007], and three times as likely to manifest FSH > 12m IU/ml (OR 3.48, 95% CI 1.46–7.32, P= 0.004). The B blood group antigen failed to exhibit any relationship with ovarian reserve as reflected by baseline FSH (P> 0.05).
Conclusions: The A blood group antigen appears to be protective for ovarian reserve, whereas blood type O appears to be associated with DOR, in a relationship that is independent of advancing age. Further studies are needed to establish causality and identify the underlying mechanisms for the association.
The concept 'ovarian reserve' reflects the quantity, and possibly the quality, of residual oocytes available for procreation (Navot et al., 1987; Scott et al., 1989; Toner et al., 1991). While numerous surrogate markers are recognized to reflect ovarian reserve, female age remains the strongest predictor of reproductive success in couples undergoing fertility treatment (Rosenwaks et al., 1995; Scott et al., 1995; Sharara et al., 1998; Levi et al., 2001). Despite accruing evidence identifying anti-Müllerian hormone and antral follicle count as sensitive prognostic markers of ovarian reserve, early follicular phase serum level of FSH appears to be the most commonly utilized parameter for assessment of ovarian reserve in clinical practice (Broekmans et al., 2006). A serum FSH level >10 mIU/ml is a commonly utilized threshold to identify women at risk for suboptimal quantitative response to ovarian stimulation and poor reproductive success, an entity alluded to as diminished ovarian reserve (DOR; Greenseid et al., 2009; Thum et al., 2009; Hurwitz et al., 2010). Our prior work has focused on elucidating mechanisms that may underlie DOR as well as assessing broader implications of DOR (Greenseid et al., 2009).
Of interest is a recent report relating blood group antigens and ovarian hyperstimulation syndrome (OHSS; Binder et al., 2008a,b). The authors observed that OHSS was more likely during the course of ovarian stimulation in infertile women with blood type A compared to those with blood type O. Bellver et al. (2010), however, failed to observe a similar relationship between blood type and likelihood of OHSS in their series. Historically, researchers have not found an association between ABO blood group and fertility, although decreased reproductive success in women exhibiting ABO incompatibility with their male partners has been reported (Behrman et al., 1960; Chakravartti and Chakravartti, 1978; Satyanarayana et al., 1978).
We herein explore the relationship between ABO blood type and ovarian reserve. Our findings suggest that blood type O may relate to an increased likelihood for DOR, and in contrast, the A antigen may be protective for ovarian reserve.
Abstract and Introduction
Abstract
Background: We explored the relevance of blood type to ovarian reserve, as reflected by early follicular phase FSH levels.
Methods: For this cross-sectional observational study, early follicular phase serum levels of FSH (mIU/ml) and estradiol (E2, pg/ml), and information on blood type (A, B, AB and O) and patient age were procured for female patients, ≤45 years age (n= 544), who were undergoing fertility evaluation at one of two tertiary care facilities. Serum FSH > 10 mIU/ml was taken to reflect diminished ovarian reserve (DOR). Data distribution for FSH and age was analyzed and non-parametric tests used for comparisons across blood groups. Multivariable logistic regression analyses determined the relationship between elevated FSH and respective blood types after adjusting for age and study site.
Results: Prevalence of blood types according to order of frequency was: O (45%), A (35%), B (16%) and AB (5%). After adjusting for age and study site, patients with blood type O were twice as likely to exhibit FSH > 10 mIU/ml compared with those with A or AB blood types [odds ratio (OR) 2.36; 95% confidence interval (CI) 1.27–4.41; P= 0.007], and three times as likely to manifest FSH > 12m IU/ml (OR 3.48, 95% CI 1.46–7.32, P= 0.004). The B blood group antigen failed to exhibit any relationship with ovarian reserve as reflected by baseline FSH (P> 0.05).
Conclusions: The A blood group antigen appears to be protective for ovarian reserve, whereas blood type O appears to be associated with DOR, in a relationship that is independent of advancing age. Further studies are needed to establish causality and identify the underlying mechanisms for the association.
Introduction
The concept 'ovarian reserve' reflects the quantity, and possibly the quality, of residual oocytes available for procreation (Navot et al., 1987; Scott et al., 1989; Toner et al., 1991). While numerous surrogate markers are recognized to reflect ovarian reserve, female age remains the strongest predictor of reproductive success in couples undergoing fertility treatment (Rosenwaks et al., 1995; Scott et al., 1995; Sharara et al., 1998; Levi et al., 2001). Despite accruing evidence identifying anti-Müllerian hormone and antral follicle count as sensitive prognostic markers of ovarian reserve, early follicular phase serum level of FSH appears to be the most commonly utilized parameter for assessment of ovarian reserve in clinical practice (Broekmans et al., 2006). A serum FSH level >10 mIU/ml is a commonly utilized threshold to identify women at risk for suboptimal quantitative response to ovarian stimulation and poor reproductive success, an entity alluded to as diminished ovarian reserve (DOR; Greenseid et al., 2009; Thum et al., 2009; Hurwitz et al., 2010). Our prior work has focused on elucidating mechanisms that may underlie DOR as well as assessing broader implications of DOR (Greenseid et al., 2009).
Of interest is a recent report relating blood group antigens and ovarian hyperstimulation syndrome (OHSS; Binder et al., 2008a,b). The authors observed that OHSS was more likely during the course of ovarian stimulation in infertile women with blood type A compared to those with blood type O. Bellver et al. (2010), however, failed to observe a similar relationship between blood type and likelihood of OHSS in their series. Historically, researchers have not found an association between ABO blood group and fertility, although decreased reproductive success in women exhibiting ABO incompatibility with their male partners has been reported (Behrman et al., 1960; Chakravartti and Chakravartti, 1978; Satyanarayana et al., 1978).
We herein explore the relationship between ABO blood type and ovarian reserve. Our findings suggest that blood type O may relate to an increased likelihood for DOR, and in contrast, the A antigen may be protective for ovarian reserve.