Effect of fetal gender on maternal serum human chorionic gonadotropin levels throughout pregnancy

Fetal sexual dimorphism of maternal thyroid function parameters during pregnancy, a single center retrospective real-world study

Introduction

Thyroid function during pregnancy fluctuates with gestational weeks, seasons and other factors. However, it is currently unknown whether there is a fetal sex-specific thyroid function in pregnant women. The purpose of this study was to investigate the fetal sex differences of maternal thyroid-stimulating hormone (TSH) and free thyroxine (FT4) in pregnant women.

Methods

This single-center retrospective real-world study was performed by reviewing the medical records of pregnant women who received regular antenatal health care and delivered liveborn infants in Shanghai First Maternity and Infant Hospital (Pudong branch), from Aug. 18, 2013 to Jul. 18, 2020. Quantile regression was used to evaluate the relationship between various variables and TSH and FT4 concentrations. The quantile regression also evaluated the sex impact of different gestational weeks on the median of TSH and FT4.

Results

A total of 69,243 pregnant women with a mean age of 30.36 years were included. 36197 (52.28%) deliveries were boys. In the three different trimesters, the median levels (interquartile range) of TSH were 1.18 (0.66, 1.82) mIU/L and 1.39 (0.85, 2.05) mIU/L, 1.70 (1.19, 2.40) mIU/L; and the median levels (interquartile range) of FT4 were 16.63 (15.16, 18.31) pmol/L, 14.09 (12.30, 16.20) pmol/L and 13.40 (11.52, 14.71) pmol/L, respectively. The maternal TSH upper limit of reference ranges was decreased more in mothers with female fetuses during gestational weeks 7 to 12, while their FT4 upper limit of the reference ranges was increased more than those with male fetuses. After model adjustment, the median TSH level was 0.11 mIU/L lower (P <0.001), and FT4 level was 0.14 pmol/L higher (P <0.001) for mothers with female fetuses than those with male fetuses during gestational weeks 9 to 12.

Discussion

We identified sexual dimorphism in maternal thyroid function parameters, especially during 9-12 weeks of pregnancy. Based on previous research, we speculated that it may be related to the higher HCG levels of mothers who were pregnant with girls during this period. However, longitudinal studies are needed to determine if fetal sex differences impact the maternal thyroid function across pregnancy.

Evaluation of serum anti-Müllerian hormone (AMH) and equine chorionic gonadotrophin (eCG) concentrations in pregnant mares in relation to foetal sex

The aim of this study was to investigate the foetal sex related difference and progression in maternal serum anti-Müllerian hormone (AMH) and equine chorionic gonadotrophin (eCG) concentrations during different points of time in pregnant Arabian mares. The study groups formed by 12 healthy male offspring- and 12 healthy female offspring-foaling mares, designated as group MFM and group FFM, respectively. Peripheral blood samples were collected on the day of natural mating and then monthly until the 6th month (mo) of gestation. Serum AMH was measured in all serum samples; eCG was measured in samples collected from 2 to 5 months Of gestation. Serum AMH concentrations of group FFM at mo 4 and mo 5 (3.89 ± 0.49 ng/ml; 2.89 ± 0.32 ng/ml), were significantly higher than in group MFM (2.11 ± 0.46 ng/ml; 1.87 ± 0.32 ng/ml), (P < 0.05). The mo of gestation (mo 1–6) had no effect on serum AMH concentrations of either group MMF or FFM (P > 0.05). Serum eCG concentrations of group FFM at mo 2 (359.73 ± 41.51 mIU/ml), were significantly higher than in group MFM (255 ± 21.18 mIU/ml) (P < 0.05). Group-time interaction for eCG concentrations at mo 2–4 was non-significant (P > 0.05). Concentrations of serum AMH showed no relationship with corresponding eCG levels at mo 2–4 (P > 0.05). Individual variations in AMH and eCG concentrations and the inability to determine a cut-off point for determination of foetal sex make these hormones unlikely candidates for determining foetal sex in the mare.

Fetal sex is associated with maternal stimulated cytokine production, but not serum cytokine levels, in human pregnancy

Some studies suggest that fetal sex plays a role in maternal physiological processes during pregnancy including glycemic control, blood pressure, and cortisol regulation. However, data examining fetal sex-specific differences in maternal immune parameters is lacking. In the current study, serum levels of interleukin(IL)-6, IL-8, and tumor necrosis factor(TNF)-α as well as LPS-stimulated production of IL-6, IL-8, TNF-α, and IL-1β by PBMCs incubated for 24h were assessed in early, mid, and late pregnancy among 80 women (46 with male and 34 with female fetuses). Linear mixed models showed that women carrying females versus males exhibited greater stimulated production of IL-6 at each timepoint (ps⩽0.03), TNF-α in early pregnancy (p=0.04), and IL-1β in mid- and late pregnancy (ps⩽0.05). Despite changes in serum levels of IL-8 (p=0.002) and TNF-α (p<0.0001) across pregnancy, no differences in any serum cytokines were observed in relation to fetal sex (ps>0.85). In conclusion, in pregnant women, those carrying female versus male fetuses exhibited greater stimulated cytokine production across pregnancy. Differential inflammatory responses could affect maternal health and fetal development. Fetal sex should be considered as a factor in studies of maternal inflammation. These findings have relevance both clinically and conceptually. For example, maternal asthma is exacerbated among women carrying female versus male fetuses. In addition, data on associations between fetal sex and maternal immune function among women with health conditions (e.g., preeclampsia) and adverse pregnancy outcomes (e.g., preterm birth) would be informative.

The effects of fetal gender on serum human chorionic gonadotropin and testosterone in normotensive and preeclamptic pregnancies

Introduction. The aim of the present study was to evaluate the effects of fetal sex on serum human chorionic gonadotropin (hCG) and testosterone in normotensive and preeclamptic pregnancies. Materials and Methods. This is a cross-sectional study and 139 women with singleton pregnancies in the third trimester were studied. Seventy-one pregnancies were uncomplicated; among those were 35 male and 36 female fetuses. Sixty-eight pregnancies were complicated by preeclampsia; among those were 35 male and 33 female fetuses. Human chorionic gonadotropin and total testosterone were measured in maternal peripheral blood. Data analyzed by SPSS software. Results. In male-bearing pregnancies, maternal hCG and testosterone serum levels were significantly higher in preeclamptic than normotensive mothers (P < 0.001 and P < 0.001, resp.) in female-bearing pregnancies testosterone levels were significantly higher in preeclamptic than normotensive mothers (P < 0.001). Total testosterone levels were significantly higher in pregnancies with either gender and significantly higher in mlae-bearing than in female-bearing pregnancies. Conclusion. According to our results, there is a correlation between maternal serum hCG and testosterone levels and preeclampsia. Therefore these tests can be used as routine during 30–38 weeks of gestation. High maternal serum concentrations of these markers can predict preeclampsia.

Urinary hCG patterns during the week following implantation

BACKGROUND

Human chorionic gonadotrophin (hCG) is used to monitor pregnancy status. Yet the pattern of hCG excretion in the first week following implantation has not been adequately described. Therefore the aim of this study was to describe the average profile of hCG and its variability during the 7 days following estimated implantation in a population of naturally conceived pregnancies.

METHODS

We measured daily hCG concentrations in first-morning urine for 142 clinical pregnancies from women with no known fertility problems. Mixed-effects regression models were used to estimate the hCG trajectory and its variability in relation to pregnancy outcomes.

RESULTS

hCG rose 3-fold between the day of detection and the next day (95% CI = 2.7-3.4). The relative rate of rise decreased thereafter, reaching 1.6-fold (95% CI = 1.5-1.8) between days 6 and 7. HCG levels followed a log-quadratic trajectory, and the patterns of rise were unrelated to number of fetuses, risk of spontaneous abortion or sex of the baby. Later implantations (after 10 luteal days) produced slower rates of increase.

CONCLUSIONS

Although mean hCG follows a log-quadratic trajectory during the first week of detectability, there is high variability across pregnancies. Later implantation may reflect characteristics of the uterus or conceptus that slow hCG production.