Cord blood thyroid-stimulating hormone level in high-risk pregnancies

Effect of Maternal Triclosan Exposure on Neonatal Thyroid-Stimulating Hormone Levels: A Cross-Sectional Study

Objective

This study is aimed at assessing the relationship between maternal urinary triclosan (uTCS) exposure and the thyroid-stimulating hormone (TSH) level of infant cord blood.

Methods

This cross-sectional study was carried out in 2019-2020 in Isfahan, Iran, and 99 pregnant women participated in the study. Urine samples were collected after the 28th week of pregnancy, and the concentration of TCS was measured using GC/MS. The cord blood levels of TSH (CBL-TSH) were measured. The association between uTCS and CBL-TSH was examined based on the general linear model.

Results

TCS was detected (≥0.01 ng/mL) in 100% of the urine samples, with the interquartile range (25%-75%) of uTCS levels 0.6-6.23 μg/g Cr. uTCS was not associated with CBL-TSH after adjustment for covariates. A significant relationship was observed between CBL-TSH of neonates born to mothers who had given birth only once compared to mothers who had given birth twice or more times.

Conclusions

Maternal exposure to TCS did not affect the infant CBL-TSH. However, the high concentrations of TCS in maternal urinary samples indicate the necessity of more precise regulations to decrease the use of this chemical in the industry and increase public awareness about using TCS-free compounds.

Delivery factors and neonatal thyroid hormone levels: a systematic review

Postnatal thyroid hormone changes enable the neonate to be adapted for postnatal life. Several factors can affect this adaption. In this review, we summarized the studies that reported the association among the delivery factors and neonatal thyroid hormones and thyroid stimulating hormone. A comprehensive literature search was performed in PubMed, Web of Science, and Scopus up to March 2020, to identify the studies investigating the relationship between delivery factors, especially the mode of delivery and labor pain, and neonatal thyroid hormones and TSH. Finally, in this review study, of 157 articles obtained in the initial search, 25 eligible studies were reviewed. Various maternal, fetal/neonatal, and obstetric factors affected neonatal TSH and thyroid hormones. Among various influencing factors, mode of delivery, labor pains, and duration of labor have a strong relationship with neonatal thyroid hormones and need to be considered for interpretation of neonatal thyroid status. The majority of the studies revealed that vaginal deliveries (instrumental or natural) lead to higher levels of cord TSH compared to elective cesarean section. This can be explained by the increased secretion of catecholamine during labor. It has been suggested that blood TSH and thyroid hormone levels are affected by perinatal stress events such as maternal anxiety, labor pains, fetal distress, and other stimulants of the catecholamine response. These changes may act as the trigger to increase thyroid hormone levels for adapting of neonates in the first hours after birth. This assumption needs to be re-evaluated by performing comprehensive and well-designed studies.

Metabolic Dynamics and Prediction of Gestational Age and Time to Delivery in Pregnant Women

Metabolism during pregnancy is a dynamic and precisely programmed process, the failure of which can bring devastating consequences to the mother and fetus. To define a high-resolution temporal profile of metabolites during healthy pregnancy, we analyzed the untargeted metabolome of 784 weekly blood samples from 30 pregnant women. Broad changes and a highly choreographed profile were revealed: 4,995 metabolic features (of 9,651 total), 460 annotated compounds (of 687 total), and 34 human metabolic pathways (of 48 total) were significantly changed during pregnancy. Using linear models, we built a metabolic clock with five metabolites that time gestational age in high accordance with ultrasound (R = 0.92). Furthermore, two to three metabolites can identify when labor occurs (time to delivery within two, four, and eight weeks, AUROC ≥ 0.85). Our study represents a weekly characterization of the human pregnancy metabolome, providing a high-resolution landscape for understanding pregnancy with potential clinical utilities.

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Weekly metabolome of maternal blood changes dynamically through healthy pregnancy

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A metabolic clock of five blood metabolites accurately predicts gestational age

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Two to three metabolites identify labor onset within two, four, and eight weeks

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Women with metabolic clocks that outpaced ultrasound evaluation tend to deliver earlier

Association of Cord Blood Thyroid-Stimulating Hormone Levels with Maternal, Delivery and Infant Factors

Abstract Introduction: This study examined maternal, delivery and infant factors associated with cord thyroid-stimulating hormone (TSH) concentrations in an Asian population. Methods: The Growing Up in Singapore Towards healthy Outcomes (GUSTO) study is a mother–offspring birth cohort from 2 major hospitals in Singapore. Cord serum TSH was measured using the Abbott ARCHITECT TSH Chemiluminescent Microparticle Immunoassay and the ADVIA Centaur TSH-3 Immunoassay. After excluding infants with a maternal history of thyroid disease, screening cord TSH results from 604 infants were available for multivariable regression analysis in relation to the factors of interest. Results: Babies born by vaginal delivery had significantly higher cord serum TSH concentrations than babies born by caesarean section. Cord serum TSH concentrations differed significantly by measurement method. There was no association of cord TSH concentrations with ethnicity, sex, birth weight, gestational age, maternal body mass index, gestational weight gain, gestational diabetes mellitus status and other maternal, delivery and infant factors studied. Conclusion: Interpretation of cord serum TSH results may need to take into account mode of delivery and measurement method. Keywords: Cord blood, Growing Up in Singapore Towards healthy Outcomes, GUSTO, perinatal

Circulating RNA Transcriptome of Pregnant Women with TSH Just Above the Trimester-Specific Reference and its Correlation with the Hypertensive Phenotype

During gestation, a woman’s body undergoes physiological changes that alter thyroid function. Pregnant women with hypothyroidism may exhibit gestational complications, including hypertension and preeclampsia. We investigated differentially expressed genes (DEGs) in circulating RNAs from pregnant women with TSH levels just above the normal range to determine the impact of a mild elevation of TSH in pregnancy. We selected three women with healthy thyroid pregnancy (HTP), three pregnant women with gestational hypothyroidism (GHT), and three nonpregnant women (NPG) to construct transcriptome libraries. We also compared our results with data from the GEO dataset and DisGeNET. We identified 1500 DEG in GHT and 1656 DEG in HTP. From GEO dataset, we recognized 453 DEGs in trimester-specific plasma RNA, 1263 DEGs in placental tissues from healthy women, 1031 DEGs from preeclamptic uteroplacental tissues and 1657 DEGs from placental tissues from severely preeclamptic women. In this scenario, 12.26% and 12.86% genes were shared between these datasets in GHT and HTP, respectively. We stablished 62 genes in GHT DEGs related to hypertensive phenotype hallmarks. In conclusion, even in women with a mild TSH increment, we were able to detect some DEGs that could be associated with a hypertensive phenotype.

Thyroid dysfunction in preterm infants born before 32 gestational weeks

Background

Thyroid hormones are critical for growth and brain development during the newborn period and infancy. Because of delayed maturation of the hypothalamic-pituitary-thyroid axis in preterm infants, thyroid dysfunction is common, and thyroid stimulating hormone (TSH) elevation is often delayed in preterm infants. The objective of this study was to determine the incidence of thyroid dysfunction requiring levothyroxine treatment and to identify its risk factors in preterm infants.

Methods

A retrospective cohort study was performed on preterm infants who were born before 32 gestational weeks and admitted to a single tertiary academic center for more than 8 weeks between January 2008 and December 2014. In these infants, serial thyroid function tests (TFTs) measuring serum TSH and free thyroxine (fT4) were routinely performed at 1, 3, and 6 weeks of postnatal age.

Results

Of the 220 preterm infants enrolled, 180 infants underwent TFTs at 1, 3, and 6 weeks of postnatal age and were included in the study. Of the 180 infants, 35 infants (19.4%) were started on levothyroxine treatment based on the results of serial TFTs. Among the 35 infants who were treated with levothyroxine, 16 infants (45.7%) had normal results on the initial TFT. Three of these 16 infants continued to have normal results on the second TFT. Thyroid dysfunction requiring levothyroxine treatment was significantly associated with maternal pregnancy-induced hypertension (adjusted odds ratio 2.64, 95% confidence interval 1.02–6.81).

Conclusions

Thyroid dysfunction requiring levothyroxine treatment occurred in nearly one-fifth of preterm infants born before 32 gestational weeks. Nearly half of the preterm infants who were treated with levothyroxine had normal TSH and fT4 levels at 1 week of postnatal age. The findings of the present study suggest that serial TFTs is important to find preterm infants who require levothyroxine treatment.

Advanced Maternal Age, Mode of Delivery, and Thyroid Hormone Levels in Chinese Newborns

Objective: Thyroid hormones are essential for fetal growth and neurodevelopment, however, data on cord blood thyroid hormones are sparse in China where maternal age at childbearing is increasing in recent decades. We aimed to assess cord blood levels of free triiodothyronine (FT3), free thyroxine (FT4), and thyroid stimulating hormone (TSH) in full-term Chinese newborns, and examine potential related perinatal factors. Methods: This study included 922 mother-newborn pairs from a prospective birth cohort enrolled in 2012-2013, Shanghai, China. Cord serum concentrations of FT3, FT4, TSH, and TPOAb were measured in newborns. Results: Newborns born via cesarean section had higher cord serum FT3 (mean ± SD: 1.90 ± 1.16 pmol/L) and lower cord serum TSH (5.15 ± 2.60 mIU/L) than those born via vaginal delivery (FT3: 1.62 ± 0.93 pmol/L; TSH: 9.27 ± 6.76 mIU/L). In cesarean section deliveries, the concentration of cord serum FT3 was 0.15 (95%CI: -0.03, 0.33; p = 0.10) pmol/L lower in infants of mothers aged 30-34 years, and 0.57 (95%CI: 0.22, 0.92; p = 0.002) pmol/L lower in infants of mothers ≥35 years compared to infants of mothers <30 years. Large-for-gestational-age (birth weight >90th percentile) was associated with higher TSH (p = 0.02). Similar results were also found in vaginal deliveries. Conclusions: In this Chinese term birth cohort, newborns born via cesarean section had higher cord serum FT3 and lower TSH than those born via vaginal delivery. Advanced maternal age was associated with lower fetal FT3. Further research is needed to understand whether this association may mediate the adverse impact of advanced maternal age on neurodevelopment in early life.

Maternal factors and complications of preterm birth associated with neonatal thyroid stimulating hormone

Thyroid hormones are important regulators of fetal neurodevelopment. Among preterm infants, thyroid stimulating hormone (TSH) is highly variable. Understanding this variability will further improvements in screening for thyroid disorders in preterm infants. We examined 61 maternal and infant clinical and demographic factors for associations with neonatal TSH levels in 698 preterm neonates. TSH was measured as part of routine State-mandated newborn screening in Iowa. Of the maternal characteristics, nulliparous women (p=8×10-4), women with preeclampsia (p=2×10-3), and those with induced labor (p=3×10-3) had infants with higher TSH levels. TSH levels at the time of newborn screening were associated with respiratory distress syndrome (RDS) (p<0.0001) and sepsis (p=3×10-3). We replicated findings between parity and preeclampsia previously observed in primarily term infants. We also observed strong relationships between neonatal TSH and complications of prematurity including RDS and sepsis, which have implications for future studies examining this relationship both prenatally and longitudinally after birth.

Influence of perinatal factors on thyroid stimulating hormone level in cord blood

Background:

The aim of the present study was to determine the effect of various perinatal factors on cord blood TSH among newborns in Isfahan, Iran.

Materials and Methods:

This was a descriptive–analytic cross sectional study which performed in Isfahan Iran. During a period of four months, since February to May 2012 a total number of 440 newborns delivered in Alzahra and Shahid beheshti hospitals were enrolled in the study. For all newborns one mL blood sample from umbilical vein was obtained by one of the project investigators and sent to laboratory for further examinations. Cord blood TSH and birth body weight (BBW), gestational age, history of gestational diabetes mellitus (GDM), apgar at one minute, apgar at five minute, newborn gender and the mother's age were documented. Differences considered statistically significant if P < 0.01.

Results:

440 newborns enrolled in the study, 221 (50.2%) were male and 219 (49.8%) were female. Among study parameters, method of delivery had statistically significant relation with cord blood TSH (P < 0.001), and other factors such as BBW, gestational age, GDM, apgar at one minute, apgar at five minute, newborn gender and the mother's age didn’t have statistically significant relationship with cord TSH level.

Conclusion:

In conclusion we deduce that the only factor that can affect cord blood TSH was method of delivery. Infant with vaginal delivery has higher TSH level in cord blood. Other factors that were evaluated in this study didn’t have any statistically significant relationship.

Correlation between the TSHRc-Asp727Glu polymorphism and plasma thyroid stimulating hormone levels in Romanian preeclamptic women

AIM

To analyze the influence of thyroid stimulating hormone (TSH) levels and/or the Asp727Glu polymorphism on the severity and perinatal outcome of preeclampsia.

METHODS

Forty-nine women with preeclampsia and 58 normal pregnant women were genotyped for the TSHRc-Asp727Glu polymorphism using PCR-RFLP methods. The plasma TSH levels were measured by ELISA method.

RESULTS

Fourteen (77.78%) women of 18 pregnant women with abnormal TSH levels had preeclampsia compared to 35 (39.33%) of 89 pregnant women with normal TSH levels who had preeclampsia (OR 5.4, p = 0.003). The mean TSH levels were 2.13 ± 1.44 μU/ml, 2.47 ± 2.03 μU/ml and 4.27 ± 2.75 μU/ml in women with pregnancy induced hypertension (PIH), mild and severe preeclampsia, respectively. OR for PIH and mild preeclampsia was 1.08 (p = 1) and 9.45 (p = 0.06), respectively, in association with the Asp/Asp genotype. All women with severe preeclampsia had the Asp/Asp genotype. The risk for preeclampsia in association with TSH > 4 μU/ml and Asp/Asp genotype is 20.8 (p < 0.01). Preeclamptic women with TSH levels > 4 μU/ml and the Asp/Asp genotype delivered earlier (weeks, 34.92 ± 4.33 vs. 36.6 ± 3.21, p = 0.3) neonates with lower birth weight (grams, 2361.54 ± 1155.81 vs. 3000 ± 1072.38, p = 0.3) than preeclamptic women with TSH levels  < 4 μU/ml and the Asp/Glu genotype.

CONCLUSIONS

Higher TSH levels and/or the TSHRc-Asp727Glu polymorphism represent risk factors for preeclampsia and could be correlated with the severity of preeclampsia.

Birth delivery mode modifies the associations between prenatal polychlorinated biphenyl (PCB) and polybrominated diphenyl ether (PBDE) and neonatal thyroid hormone levels

BACKGROUND

Developing infants may be especially sensitive to hormone disruption from chemicals including polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs).

OBJECTIVE

We investigated relationships between cord serum levels of PCBs and PBDEs and thyroid hormones measured in cord blood serum and neonatal blood spots.

METHODS

We measured PCBs and PBDEs, thyrotropin (TSH), thyroxine (T4) and free T4 (FT4) in cord blood serum from 297 infants who were delivered at the Johns Hopkins Hospital in 2004-2005. We abstracted results of total T4 (TT4) measured in blood spots collected in the hospital and at neonatal visits. We used delivery mode (augmented vaginal deliveries and nonelective cesarean deliveries) as a surrogate for intrapartum stress, which is known to alter cord blood thyroid hormones.

RESULTS

In the full study population, no compounds were associated with a change in average TSH, FT4, or TT4. BDE-100 was associated with increased odds of low cord TT4, BDE-153 with increased odds of low cord TT4 and FT4, and no compounds were associated with increased odds of high TSH. For infants born by spontaneous, vaginal, unassisted deliveries, PCBs were associated with lower cord TT4 and FT4 and lower TT4 measured in neonatal blood spots. PBDEs showed consistent but mainly nonsignificant negative associations with TT4 and FT4 measurements.

CONCLUSIONS

Prenatal PCB and PBDE exposures were associated with reduced TT4 and FT4 levels among infants born by spontaneous, unassisted vaginal delivery. Intrapartum stress associated with delivery mode may mask hormonal effects of PCBs and PBDEs.

The effect of the mode of delivery on neonatal thyroid function

BACKGROUND

We aimed to investigate the effect of the mode of delivery and the type of anesthesia on postnatal thyroxine (T4), free T4 (f-T4) and thyroid-stimulating hormone (TSH) in a large number of healthy full-term neonates.

METHODS

Serum samples for T4, TSH and f-T4 were drawn from neonates at the time of discharge (postnatal days 1-7) in a pilot thyroid-screening program. Six hundred and thirty-eight neonates were grouped as: vaginal delivery (VD; 332), elective cesarean section (elective C/S; 252) and emergency cesarean section (emergency C/S; 54). The elective C/S group was subdivided into local and general anesthesia groups to investigate the influence of the type of anesthesia used on thyroid function.

RESULTS

Mean+/-SD serum T4, TSH and f-T4 levels tended to be higher in the VD group compared to the elective C/S group at almost all time points. However the differences did not reach statistical significance, except for the T4 levels at postnatal day 3 in the VD group, which was higher (195.6+/-37.3 nmol/L) compared to the elective C/S group (160.9+/-34.8 nmol/L) (p < 0.001). The only difference in the anesthesia groups was the slightly higher f-T4 levels from postnatal day 4 in the local anesthesia group compared to the general anesthesia group.

CONCLUSIONS

The mode of delivery or type of anesthesia does not have considerable influence on postnatal thyroid functions in the neonates, although minor differences exist. Therefore similar cut-off values can be used for thyroid screening of term newborns regardless of the mode of delivery or type of anesthesia used.

Predictors of AVP and TSH levels and the timing of first voiding in the newborn

To evaluate obstetric predictors of umbilical cord plasma AVP levels, serum TSH levels and the timing of first voiding, 87 singleton term newborns were divided into three groups: group A, vaginal delivery (n = 30); group B, cesarean section (CS) during labor (n = 26); and group C, elective CS (n = 31). The AVP concentration was 120 (0.7-2170) ng/L in group A, 1.8 (0.01-183) ng/L in group B, and 0.8 (0.01-30) ng/L in group C (p < 0.001). In group A, the TSH concentration was 10.20 (3.5-30.80) mU/L; in group B, 5.40 (2.10-43.00) mU/L; and in group C, 5.30 (2.90-11.00) mU/L (p = 0.001). Duration of labor had a positive correlation with AVP (p < 0.001) and TSH (p = 0.001) concentrations. The timing of first voiding had a positive correlation with gestational age (p = 0.003), volume of additional feeding before first voiding (p < 0.001), and umbilical AVP concentration (p = 0.023). The AVP and TSH concentrations are associated with mode of delivery and duration of labor and AVP levels also with the timing of first voiding in the newborn.

Cord blood thyroid-stimulating hormone level and risk of acidosis at birth

OBJECTIVE

Cord blood thyroid-stimulating hormone level is elevated in neonates who had undergone more perinatal stresses. The present study aimed to evaluate the cord blood acid-base status in neonates with elevated thyroid-stimulating hormone level.

STUDY DESIGN

The study population consisted of 2366 singleton, term pregnancies. Subjects were categorized by their cord blood thyroid-stimulating hormone level into four quartiles, and cord blood acid-base parameters were compared among the four groups. The correlations between cord acid-base parameters and thyroid-stimulating hormone level were also studied.

RESULTS

Cord blood pH was significantly lower in the highest (arterial, 7.27+/-0.08; venous, 7.32+/-0.07) and second highest thyroid-stimulating hormone quartile groups (arterial, 7.29+/-0.07; venous, 7.34+/-0.06) compared to the lowest quartile group (arterial, 7.30+/-0.06; venous, 7.35+/-0.05). Incidences of cord arterial pH < or =7.20 were 4.7%, 6.8%, 10.9%, and 17.3% in lowest to the highest thyroid-stimulating hormone quartile groups, respectively. There was a significant negative correlation between cord blood thyroid-stimulating hormone level and cord arterial and venous pH (r=-0.26, P<0.001). When stratified according to the mode of delivery, the negative correlations remained significant in neonates delivered vaginally and by intrapartum emergency cesarean section but not in neonates delivered by elective cesarean section.

CONCLUSION

Incidence of cord blood acidosis is significantly higher in neonates with elevated thyroid-stimulating hormone level. This findings support the postulation that stress-induced elevation of cord blood thyroid-stimulating hormone level may be mediated through intrapartum fetal hypoxia.