Umbilical artery time-averaged maximum velocity: First trimester reference range

AbstractThis second part on Doppler sonography in prenatal medicine and obstetrics reviews its clinical applications. While this has not become the initially anticipated screening tool, it is used for the diagnosis and surveillance of a variety of fetal pathologies. For example, the sonography-based determination of uterine artery blood flow indices is an important parameter for the first trimester multimodal preeclampsia risk assessment, increasing accuracy and providing indication for the prophylactic treatment with aspirin. It also has significant implications for the diagnosis and surveillance of growth-restricted fetuses in the second and third trimesters through Doppler-sonographic analysis of umbilical artery, middle cerebral artery and ductus venosus. Here, especially the hemodynamics of the ductus venosus provides a critical criterium for birth management of severe, early-onset FGR before 34 + 0 weeks of gestation. Further, determination of maximum blood flow velocity of the middle cerebral artery is a central parameter in fetal diagnosis of anemia which has been significantly improved by this analysis. However, it is important to note that the mentioned improvements can only be achieved through highest methodological quality. Importantly, all these analyses are also applied to twins and higher order multiples. Here, for the differential diagnosis of specific complications such as TTTS, TAPS and TRAP, the application of Doppler sonography has become indispensable. To conclude, the successful application of Doppler sonography requires both exact methodology and precise pathophysiological interpretation of the data.

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Plasma mineral (selenium, zinc or copper) concentrations in the general pregnant population, adjusted for supplement intake, in relation to thyroid function

British Journal Of Nutrition ◽

10.1017/s000711452000255x ◽

2020 ◽

Vol 125 (1) ◽

pp. 71-78

Author(s):

Victor Pop ◽

Johannes Krabbe ◽

Wolfgang Maret ◽

Margaret Rayman

Keyword(s):

Thyroid Function ◽

Reference Range ◽

First Trimester ◽

Future Research ◽

Thyroid Peroxidase ◽

Reference Ranges ◽

Lower Plasma ◽

The Mean ◽

The Impact ◽

Supplement Intake

AbstractThe present study reports on first-trimester reference ranges of plasma mineral Se/Zn/Cu concentration in relation to free thyroxine (FT4), thyrotropin (TSH) and thyroid peroxidase antibodies (TPO-Ab), assessed at 12 weeks’ gestation in 2041 pregnant women, including 544 women not taking supplements containing Se/Zn/Cu. The reference range (2·5th–97·5th percentiles) in these 544 women was 0·72–1·25 µmol/l for Se, 17·15–35·98 µmol/l for Cu and 9·57–16·41 µmol/l for Zn. These women had significantly lower mean plasma Se concentration (0·94 (sd 0·12) µmol/l) than those (n 1479) taking Se/Zn/Cu supplements (1·03 (sd 0·14) µmol/l; P < 0·001), while the mean Cu (26·25 µmol/l) and Zn (12·55 µmol/l) concentrations were almost identical in these sub-groups. Women with hypothyroxinaemia (FT4 below reference range with normal TSH) had significantly lower plasma Zn concentrations than euthyroid women. After adjusting for covariates including supplement intake, plasma Se (negatively), Zn and Cu (positively) concentrations were significantly related to logFT4; Se and Cu (but not Zn) were positively and significantly related to logTSH. Women taking additional Se/Zn/Cu supplements were 1·46 (95 % CI 1·09, 2·04) times less likely to have elevated titres of TPO-Ab at 12 weeks of gestation. We conclude that first-trimester Se reference ranges are influenced by Se-supplement intake, while Cu and Zn ranges are not. Plasma mineral Se/Zn/Cu concentrations are associated with thyroid FT4 and TSH concentrations. Se/Zn/Cu supplement intake affects TPO-Ab status. Future research should focus on the impact of trace mineral status during gestation on thyroid function.

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Intracerebral, aortic, and umbilical artery flow velocity waveforms in the late-first-trimester fetus

American Journal of Obstetrics and Gynecology ◽

10.1016/0002-9378(92)91827-w ◽

1992 ◽

Vol 166 (1) ◽

pp. 46-49 ◽

Cited By ~ 24

Author(s):

Juriy W. Wladimiroff ◽

Tjeerd W.A. Huisman ◽

Patricia A. Stewart

Keyword(s):

Flow Velocity ◽

Umbilical Artery ◽

First Trimester ◽

Artery Flow

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OP23.05: Diagnosis and counseling of women with single umbilical artery should be confined to first-trimester

Ultrasound in Obstetrics and Gynecology ◽

10.1002/uog.8140 ◽

2010 ◽

Vol 36 (S1) ◽

pp. 119-119

Author(s):

J. Szabó ◽

E. Horváth ◽

J. Szabó ◽

K. Szili ◽

J. Sikovanyecz

Keyword(s):

Umbilical Artery ◽

First Trimester ◽

Single Umbilical Artery

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ABSENT END-DIASTOLIC FLOW IN FIRST TRIMESTER UMBILICAL ARTERY

The Lancet ◽

10.1016/s0140-6736(88)90854-9 ◽

1988 ◽

Vol 332 (8622) ◽

pp. 1256-1257 ◽

Cited By ~ 31

Author(s):

NicholasM Fisk ◽

Neil Maclachlan ◽

Cheryl Ellis ◽

Yuen Tannirandorn ◽

H Margaret Tonge ◽

...

Keyword(s):

Umbilical Artery ◽

First Trimester ◽

Diastolic Flow

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Does foetal gender influence maternal thyroid parameters in pregnancy?

European Thyroid Journal ◽

10.1530/etj-21-0001 ◽

2022 ◽

Vol 11 (1) ◽

Author(s):

Georgiana Sitoris ◽

Flora Veltri ◽

Pierre Kleynen ◽

Malika Ichiche ◽

Serge Rozenberg ◽

...

Keyword(s):

Reference Range ◽

Thyroid Autoimmunity ◽

First Trimester ◽

Thyroid Peroxidase ◽

Reference Ranges ◽

Free T4 ◽

Cross Sectional ◽

Maternal Thyroid ◽

Serum Tsh ◽

Tsh Levels

Objective It is unknown if foetal gender influences maternal thyroid function during pregnancy. We therefore investigated the prevalence of thyroid disorders and determined first-trimester TSH reference ranges according to gender. Methods A cross-sectional study involving 1663 women with an ongoing pregnancy was conducted. Twin and assisted pregnancies and l-thyroxine or antithyroid treatment before pregnancy were exclusion criteria. Serum TSH, free T4 (FT4) and thyroid peroxidase antibodies (TPOAb) were measured at median (interquartile range; IQR) 13 (11–17) weeks of gestation. Subclinical hypothyroidism (SCH) was present when serum TSH levels were >3.74 mIU/L with normal FT4 levels (10.29–18.02 pmol/L), and thyroid autoimmunity (TAI) was present when TPOAb were ≥60 kIU/L. Results Eight hundred and forty-seven women were pregnant with a female foetus (FF) and 816 with a male foetus (MF). In women without TAI and during the gestational age period between 9 and 13 weeks (with presumed high-serum hCG levels), median (IQR range) serum TSH in the FF group was lower than that in the MF group: 1.13 (0.72–1.74) vs 1.24 (0.71–1.98) mIU/L; P = 0.021. First-trimester gender-specific TSH reference range was 0.03–3.53 mIU/L in the FF group and 0.03–3.89 mIU/L in the MF group. The prevalence of SCH and TAI was comparable between the FF and MF group: 4.4% vs 5.4%; P = 0.345 and 4.9% vs 7.5%; P = 0.079, respectively. Conclusions Women pregnant with an MF have slightly but significantly higher TSH levels and a higher upper limit of the first-trimester TSH reference range, compared with pregnancies with a FF. We hypothesise that this difference may be related to higher hCG levels in women pregnant with a FF, although we were unable to measure hCG in this study. Further studies are required to investigate if this difference has any clinical relevance.

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Therapeutic levetiracetam monitoring during pregnancy: “mind the gap”

Therapeutic Advances in Chronic Disease ◽

10.1177/2040622319851652 ◽

2019 ◽

Vol 10 ◽

pp. 204062231985165 ◽

Cited By ~ 2

Author(s):

Maya Berlin ◽

Dana Barchel ◽

Revital Gandelman-Marton ◽

Nurit Brandriss ◽

Ilan Blatt ◽

...

Keyword(s):

Reference Range ◽

Serum Levels ◽

First Trimester ◽

Second Trimester ◽

Serum Concentrations ◽

Third Trimester ◽

The Third ◽

Antiepileptic Medication ◽

Apparent Clearance ◽

Neurological Conditions

Background: Epilepsy is one of the most common chronic neurological conditions and its treatment during pregnancy is challenging. Levetiracetam (LEV) is an antiepileptic medication frequently used during pregnancy. Only a few small studies have been published on LEV monitoring during pregnancy, demonstrating decreased serum LEV levels during the first and second trimester; however, the most significant decrease was observed during the third trimester of pregnancy. In this study we aimed to evaluate LEV pharmacokinetics during different stages of pregnancy. Methods: We followed up and monitored serum levels of pregnant women treated with LEV for epilepsy. Results: Fifty-nine women with 66 pregnancies during the study period were included. The lowest raw LEV serum concentrations were observed during the first trimester. Compared with the pre-pregnancy period, raw serum concentration was lower by 5.76 mg/L [95% confidence interval (CI) (2.78, 8.75), p = 0.039] during the first trimester. Comparing the decrease in the first trimester with either the second or the third, no significant changes were observed ( p = 0.945, p = 0.866). Compared with pre-pregnancy measurements, apparent clearance was increased by 71.08 L/day [95%CI (16.34, 125.83), p = 0.011] during the first trimester. About 30% of LEV serum levels during pregnancy were below the laboratory quoted reference range. Conclusions: Raw LEV serum levels tend to decrease during pregnancy, mainly during the first trimester contrary to previous reports. Monitoring of LEV serum levels is essential upon planning pregnancy and thereafter if pre-pregnancy LEV levels are to be maintained. However, more studies are needed to assess the correlation with clinical outcome.

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