Second-trimester thyroid function and pregnancy outcome in mothers with hyperthyroidism. Birth weight related to mid-trimester triiodothyronine and RBC zinc

Association of selenium, zinc and copper concentrations during pregnancy with birth weight: A systematic review and meta-analysis

BACKGROUND

Normal fetal growth is associated with maternal nutrition. Trace elements play important roles in fetus growth. This review aims to provide a summary of the literature evaluating the relation between selenium, zinc and copper levels during pregnancy with birth weight.

METHOD

A systematic literature search was conducted in Medline database (PubMed), Scopus, Web of science and Google scholar up to September 2020. Fifty observational studies were included in the final analyses. The desired pooled effect size was considered as standardized mean differences with 95 % CI or correlation. Cochran's Q statistic was used to test the heterogeneity between the included studies (I²).

RESULT

A significant differences were found between pooled standardized mean differences (SMD) of umbilical cord blood copper levels in small-for-gestational age birth weight (SGA) and appropriate-for-gestational age birth weight (AGA) (SMD: 0.34 μg/L, 95 % CI: 0.13 to 0.56). There was a significant pooled correlation between umbilical cord blood selenium concentrations and birth weight (r: 0.08, 95 % CI: 0.01 to 0.16). A significant pooled correlation was found between umbilical cord blood zinc concentrations and birth weight (r: 0.09, 95 % CI: 0.04 to 0.15), with significant heterogeneity (I² % = 0.63). There was significant positive association between maternal blood zinc concentrations and birth weight.

CONCLUSION

Findings showed the association of trace elements including selenium, zinc and copper during pregnancy with birth weight. There was significant correlation between umbilical cord and maternal blood selenium and zinc levels with birth weight. The umbilical cord blood copper levels in SGA birth weight was higher than copper levels in AGA birth weight.

Uneventful delivery of two pregnancies in a woman with severe factor XII deficiency: case report and systematic review

Background

Deficiency of factor XII (FXII) is widely considered to have a detrimental effect on pregnancy. Several reports underline the increased risk for antenatal complications with few published case reports of uncomplicated deliveries. The main objective of our article is to perform a systematic review to highlight pregnancies with severe deficiency of FXII that have been delivered uneventfully, along with presenting our relative case of a woman with severe deficiency of FXII.

Materials and methods

A systematic review was performed in the Pubmed database. Inclusion criteria were considered to be case reports and case series presenting delivery of uncomplicated pregnancies in women with severe FXII deficiency. Medical records of our patient were also reviewed in terms of signs and symptoms, laboratory and imaging examinations and neonatal outcomes.

Results

There were 62 abstracts derived while 44 were assessed for eligibility. There were finally three case reports of women with FXII deficiency delivering live newborns and one case series of 12 women with a final outcome of 19 deliveries. Regarding our case presentation, the woman with FXII levels <12%, after a neonatal death because of extreme prematurity (24 weeks + 4 days), was set in regular follow-up and treatment with bemiparin natriate, 3.5 mg/kg and acetylsalicylic acid, 100 mg/day. She finally managed to have her second pregnancy delivered at 38 weeks + 3 days, her third pregnancy ended up as a miscarriage and her fourth pregnancy was also delivered at 37 weeks + 4 days.

Conclusion

Despite the increased risk for antenatal complications, appropriate follow-up of pregnancies with severe FXII pregnancy may finally lead to an uneventful delivery.

Effect of maternal hyperthyroidism during late pregnancy on the risk of neonatal low birth weight

OBJECTIVE

Hyperthyroidism in pregnancy occurs with a prevalence of 0.05--0.2% and has been shown to affect neonatal outcomes. Fetal weight increases markedly during the third trimester of pregnancy. This retrospective study was performed to examine the effect of maternal hyperthyroidism during late pregnancy on neonatal birth weight (NBW).

DESIGN

Medical and obstetric records of 293 pregnant women with present and past history of hyperthyroidism were retrospectively reviewed.

PATIENTS

There were 188 records of 181 patients with adequate data for inclusion in the analysis. The patients were divided into two groups according to the maternal thyroid function during the third trimester of pregnancy: hyperthyroidism (HT; 35 cases) and euthyroidism (ET; 153 cases).

MEASUREMENTS

Maternal thyroid function tests were periodically evaluated before and during the third trimester of pregnancy. Neonatal thyroid function tests and birth weight of the newborn infants were also assessed.

RESULTS

There was no significant difference of maternal age between HT and ET groups mean +/- SD (27.6 +/- 5.5 vs. 29.2 +/- 5.4 years). The NBW of the HT group was not significantly different from that of the ET group (2880 +/- 590 vs. 3019 +/- 426 g). However, the prevalence of infants with low birth weight (LBW) defined as NBW of lower than 2500 g in HT group was 22.9% which was significantly higher than the 9.8% in the ET group (P = 0.039, OR = 2.7, 95%CI = 1.1--7.1) and 9.7% of infants born to healthy mothers at Siriraj Hospital (control group) between 1991 and 1995 (P = 0.01, OR = 2.7, 95%CI = 1.3--6.1). The 90% CI for the true difference between the prevalence of LBW infants born to ET and HT mothers was 0.7--25.4. There was no significant difference in the prevalence of LBW infants in ET and control groups. Multiple logistic regression analyses showed that maternal hyperthyroidism during the third trimester of pregnancy was an independent factor associated with increased prevalence of LBW infants (P = 0.037, OR = 4.1, 95%CI = 1.1--15.0).

CONCLUSIONS

Maternal hyperthyroidism during the third trimester of pregnancy independently increases the risk of low birth weight by 4.1-fold. Appropriate management of hyperthyroidism throughout pregnancy is essential in the prevention of this undesirable neonatal outcome.