Maternal Diabetes and Infant Sex Ratio

Associations of maternal serum folate, vitamin B12 and their imbalance with gestational diabetes mellitus: The mediation effects of the methionine cycle related metabolites

BACKGROUND & AIMS

Maternal high level of folate and low level of vitamin B12, namely "folate and vitamin B12 imbalance", has been found to be associated with metabolic disorders, such as gestational diabetes mellitus (GDM). The aims of this study were to explore the associations of maternal serum folate, vitamin B12 and their imbalance in early pregnancy with GDM, and to explore the potential mediation effects of the methionine cycle related metabolites on the above associations.

METHODS

This nested case-control study (172 GDM case-control pairs) was conducted based on a prospective birth cohort. Serum concentrations of 5-methyltetrahydrofolate (5-MTHF), vitamin B12 and methionine cycle related metabolites [S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH) and Homocysteine (Hcy)] were detected. 5-MTHF (nmol/L)/vitamin B12 (pmol/L) times 1000 was calculated to indicate the imbalance status of folate and vitamin B12. Conditional logistic regression was performed to analyze the associations of 5-MTHF, vitamin B12 and their imbalance with GDM. The mediation effect models were applied to explore the mechanism.

RESULTS

High serum level of 5-MTHF in early pregnancy was related to a higher risk of GDM (OR = 2.00, 95%CI: 1.19-3.37). Compared with the group of the lowest tertile concentration of vitamin B12, the group of the highest concentration had a lower risk of GDM (OR = 0.33, 95%CI: 0.11-0.97). Higher 5-MTHF/vitamin B12 was associated with a higher risk of GDM (OR = 1.67, 95%CI: 1.08-2.56). Besides, no significant mediation effect of methionine cycle related metabolites was found on the associations of folate, vitamin B12 and the imbalance status with the risk of GDM.

CONCLUSIONS

High maternal serum folate, low vitamin B12 levels and the resulting imbalance may increase the risk of GDM. The theory of "folate trap" could not explain the effect of folate, vitamin B12 and their imbalance on GDM.

Effects of male hepatitis B virus infection and serostatus on sperm quality, pregnancy outcomes, and neonatal outcomes following intrauterine insemination

OBJECTIVE

To evaluate the impact of male hepatitis B virus (HBV) infection and serostatus on sperm quality, pregnancy outcomes, and neonatal outcomes following intrauterine insemination for infertility.

DESIGN AND METHODS

We retrospectively analyzed data from 962 infertile couples undergoing intrauterine insemination treatment at a single center. The case group comprised 212 infertile couples with male HBV infection, and the control group comprised 750 noninfected infertile couples. The couples were further divided into subgroups according to their hepatitis B e antigen (HBeAg)/anti-HBe status: hepatitis B surface antigen (HBsAg)+HBeAg- (group A), HBsAg+HBeAg+ (group B), and HBsAg-HBeAg- (control group). The main outcome parameters, including the seminal parameters, clinical pregnancy rate, miscarriage rate, live birth rate, preterm delivery rate, multiple pregnancy rate, delivery type, birth weight, and sex ratio, were compared.

RESULTS

A lower sperm acrosin activity, higher cesarean rate, and newborn sex ratio were observed in the HBV-infected group and group A in comparison with the control group (P < 0.05). However, the standard sperm parameters, clinical pregnancy rate, miscarriage rate, live birth rate, preterm delivery, and birth weight showed no statistically significant differences among the groups.

CONCLUSION

Male HBV infection does not adversely impact standard sperm parameters or pregnancy outcomes but can influence sperm acrosin activity and some neonatal outcomes. Moreover, the effect may vary among different HBV serostatuses.