TY - JOUR
T1 - Women with Recurrent Pregnancy Loss More Often Have an Older Brother and a Previous Birth of a Boy
T2 - Is Male Microchimerism a Risk Factor?
AU - Nørgaard-Pedersen, Caroline
AU - Kesmodel, Ulrik Schiøler
AU - Christiansen, Ole B
PY - 2021/6/14
Y1 - 2021/6/14
N2 - Known etiologic factors can only be found in about 50% of patients with recurrent pregnancy loss (RPL). We hypothesized that male microchimerism is a risk factor for RPL and aimed to explore whether information on family tree and reproductive history, obtained from 383 patients with unexplained RPL, was supportive of this hypothesis. The male:female sex ratio of older siblings was 1.49 (97:65) in all RPL patients and 1.79 (52:29) in secondary RPL (sRPL) patients, which differed significantly from the expected 1.04 ratio (p = 0.027 and p = 0.019, respectively). In contrast, the sex ratio of younger siblings was close to the expected ratio. Sex ratio of the firstborn child before sRPL was 1.51 (p = 0.026). When combined, 79.1% of sRPL patients had at least one older brother, a firstborn boy, or both. This differed significantly from what we expected based on the distribution of younger siblings and a general 1.04 sex ratio of newborns (p = 0.040). We speculate whether (s)RPL patients possibly acquired male microchimerism from older brother(s) and/or previous birth of boy(s) by transplacental cell trafficking. This could potentially have a detrimental impact on their immune system, causing a harmful response against the fetus or trophoblast, resulting in RPL.
AB - Known etiologic factors can only be found in about 50% of patients with recurrent pregnancy loss (RPL). We hypothesized that male microchimerism is a risk factor for RPL and aimed to explore whether information on family tree and reproductive history, obtained from 383 patients with unexplained RPL, was supportive of this hypothesis. The male:female sex ratio of older siblings was 1.49 (97:65) in all RPL patients and 1.79 (52:29) in secondary RPL (sRPL) patients, which differed significantly from the expected 1.04 ratio (p = 0.027 and p = 0.019, respectively). In contrast, the sex ratio of younger siblings was close to the expected ratio. Sex ratio of the firstborn child before sRPL was 1.51 (p = 0.026). When combined, 79.1% of sRPL patients had at least one older brother, a firstborn boy, or both. This differed significantly from what we expected based on the distribution of younger siblings and a general 1.04 sex ratio of newborns (p = 0.040). We speculate whether (s)RPL patients possibly acquired male microchimerism from older brother(s) and/or previous birth of boy(s) by transplacental cell trafficking. This could potentially have a detrimental impact on their immune system, causing a harmful response against the fetus or trophoblast, resulting in RPL.
KW - Habitual abortion
KW - Microchimerism
KW - Recurrent pregnancy loss
KW - Reproductive immunology
KW - Y chromosome
UR - http://www.scopus.com/inward/record.url?scp=85114065251&partnerID=8YFLogxK
U2 - 10.3390/jcm10122613
DO - 10.3390/jcm10122613
M3 - Journal article
C2 - 34198508
SN - 2077-0383
VL - 10
JO - Journal of Clinical Medicine
JF - Journal of Clinical Medicine
IS - 12
M1 - 2613
ER -