Comparison of the etiological results and live birth rates between 55 carriers and 229 non-carriers
Because it is difficult to achieve the complete the pregnancy results from thousands of patients from 2008 to 2018, 428 RM couples with normal chromosomes who came to our outpatient department in the whole year of 2018 were selected and followed up for 2 years. They completed all etiological screenings and 229 of them were pregnant in the follow-up period as in the figure 1. Comparison of 55 carriers and 229 non-carriers showed that female carriers were younger at the time of consultation, while other clinical characteristics and combined pathological factors were not statistically different in Table 1. The outcome after the pregnancy, namely the live birth rate (LBR), was also not statistical different (p=0.87). Among the 55 carriers, 51 carriers with primary recurrent miscarriage (no previous live birth history), and 4 were secondary recurrent miscarriages. 6 females were diagnosed with polycystic ovary syndrome (PCOS, according to the Rotterdam criteria[13]), and 3 females were diagnosed with decreased ovarian reserve (DOR, according to the hormonal markers and ultrasound parameters[14]). To further analyze of other etiological screening results in the 55 carriers, 8 cases (14.6%) were positive for infection factors (including male or female genital tract Mycoplasma and Chlamydia infection), 2 cases (3.64%) were with abnormal uterine anatomical structure, 14 cases (25.5%) were with imbalance of peripheral blood lymphocyte subsets, 9 cases (16.4%) were with endocrine disorders (including ovarian hormone abnormalities, thyroid hormone abnormalities and hyperprolactinemia), 7 cases (12.7%) were with nutritional element deficiency (including folic acid and vitamin B12). Among the combined autoimmune antibodies, 13 cases (23.64%) were positive for anti-phospholipid antibodies, and 9 cases (16.4%) were positive for connective tissue antibodies. During the follow-up period 40 in 55 pregnant RM carriers gave birth to healthy babies in the way of natural conception or intrauterine insemination without IVF/PGD, the live birth rate (LBR) in the carriers (72.7%) was similar to that in the non-carriers (71.2%). It could be seen that, apart from age, the above-mentioned combined pathological factors and the final LBR was not statistically different between carriers and non-carriers in the Table 1. The results were still consistent after using binary logistic analysis to adjust the age factor.
Table 2 showed the details of every patient number, the age of the female, the karyotypes of the female and the male, the number of miscarriages and the outcome of pregnancy of 55 carriers. 40 of 55 carriers gave birth to healthy newborns at the end with the LBR of 72.73%. Among the 40 cases, 7 cases were numerical abnormalities (LBR of 87.5%) and 33 cases were structural abnormalities (LBR of 70.21%). The structural abnormalities included 14 cases with balanced ectopic (LBR of 60.87%), 17 cases with inverted position (LBR of 80.95%), and 2 cases with Robertsonian translocations (LBR of 66.67%). As shown in Figure 4, there was no statistical difference in the LBR in the four types of chromosomal abnormalities (p=0.35).
Among the 55 pregnant couples, 34 were female and 21 were male carriers. In the Table 3 we analyzed the women’s age, number of miscarriages, distribution of karyotype abnormalities and the total LBR in female and male carriers respectively. There was no statistical difference in all items and showed gender of carrier had no effect on the pregnancy outcome (p=0.428).
In order to rule out the influence of other etiological factors on the pregnancy outcomes, we analyzed the female age, the number of abortions, infection factors, anatomical uterine abnormalities, autoimmune antibodies positive rate, blocking antibody deficiency, peripheral blood lymphocyte subset disorders, endocrine disorders and nutritional elements deficiency between 40 carriers with live birth and 15 carriers with miscarriage again in the Table 4. All the differences in above items between the two groups were not statistically significant and no one showed huge influence to alter pregnant outcomes.