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Biomedical subjects

T T Lao

Publications and source records attributed to T T Lao.

At least 19 recordsLinked to original sources
PubMed1992

Transient neonatal hyperthyrotropinaemia.

Of 48 consecutive newborns with elevated umbilical venous plasma thyrotropin (TSH) concentration, only two (4%) were subsequently proved to have congenital hypothyroidism, while the other 46 had transient elevation of TSH. Compared with matched controls, these 46 newborns were all delivered vaginally (P less than 0.0003) and had a longer second stage of labour (P less than 0.002), together with higher incidences of nuchal encirclement of the cord (P less than 0.05) as well as female babies (P less than 0.05). There was no difference in the incidence of antenatal complications, mean gestational age, birth weight, or birth asphyxia. There were no small-for-gestational age infants in the study group, while four were found in the controls. The results indicate that elevated umbilical cord plasma TSH concentration may represent a response to the stress of difficult or complicated delivery in the healthy appropriate- or large-for-gestational age newborn who does not have congenital hypothyroidism.

Delivery, Obstetric↗
PubMed1991

Relationship between newborn and maternal iron status and haematological indices.

The haemoglobin, mean corpuscular volume, mean corpuscular haemoglobin, haematocrit, serum iron and total iron binding capacity, and serum ferritin concentrations in umbilical cord blood samples taken from 96 appropriate-for-gestational age infants delivered at term were measured and compared to the respective maternal values measured at 36 weeks' gestation. All the values were higher in cord blood. Only maternal mean corpuscular volume and mean corpuscular haemoglobin were correlated with cord serum iron. Cord blood haematological indices were not correlated with either gestation at delivery or birth weight. However, newborn serum ferritin was positively correlated with gestation at delivery, while the maternal:newborn ferritin ratio was inversely correlated with gestation and birth weight. The results suggest that maternal haematological and iron indices are not predictive of the haemoglobin or iron status of the newborn, and that the fetus continues to take up iron from the mother until delivery.

Adult↗
PubMed1991

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

Thyroid function at 24-28 weeks gestation was compared between 26 mothers with hyperthyroidism (16 on antithyroid treatment and 10 in remission without treatment) and 15 normal pregnant controls. There was no difference in the total and free thyroxine (TT4 and FT4) or in the total and free triiodothyronine (TT3 and FT3) concentrations, but the erythrocyte zinc (RBC Zn) concentration was significantly lower in the study group (187.3 +/- 46.6 mumol/l RBC versus 223.6 +/- 3.7 mumol/l RBC, p less than 0.01). In the study group, both birth weight and gestation at delivery were significantly correlated with TT3 (r = -0.500, p less than 0.02 and r = -0.460, p less than 0.05, respectively) as well as with RBC Zn (r = 0.473, p less than 0.02 and r = 0.573, p less than 0.01, respectively). The results suggest that plasma concentration of TT3 and of RBC Zn at 24-28 weeks gestation may be helpful prognostic factors in the management of pregnant patients with hyperthyroidism.

Adult↗
PubMed1991

Factor XII deficiency and pregnancy.

A 19-year-old primigravida with known factor XII deficiency (prepregnant factor XII level of 21%) presented with placental abruption and preterm labor at 26 weeks' gestation. A healthy 925-g female infant was born by spontaneous vaginal delivery. The mother had no postpartum hemorrhage or further complications, and the infant demonstrated no intracranial or other forms of hemorrhage up to 70 days of age. The infant's factor XII level was 34% (normal for her age). There are only two previous reports of factor XII deficiency in pregnancy cited in the English literature, and both were uncomplicated. In view of the risk of thromboembolic complications in nonpregnant individuals with factor XII deficiency, pregnant women with a prolonged activated partial thromboplastin time and no lupus anticoagulant or anticardiolipin antibody syndrome should also be investigated for deficiencies of factors VIII, IX, and XII. These patients should be given the appropriate counseling and should be monitored for features of thromboembolism if factor XII deficiency is confirmed.

Abruptio Placentae↗
PubMed1990

Plasma and erythrocyte zinc and birth weight in pre-eclamptic pregnancies.

Plasma and erythrocyte zinc concentrations in 45 proteinuric pre-eclamptic Chinese women were measured. There was no difference in either the plasma or erythrocyte zinc concentration between pre-eclamptic patients with and without intrauterine growth retardation. There was no correlation between either plasma or erythrocyte zinc concentration with the gestation at delivery, birth weight, mean arterial pressure and plasma albumin concentration. On the other hand, both plasma albumin concentration and mean arterial pressure were significantly correlated to birth weight, and the mean arterial pressure was also significantly higher in patients with intrauterine growth retardation. Plasma and erythrocyte zinc are not useful as indices of severity in pre-eclampsia.

Adult↗
PubMed1990

Non-immune hydrops fetalis.

This article reviews the various aspects of non-immune hydrops fetalis, including the historical background, aetiology, clinical presentation, antenatal diagnosis and perinatal management, as well as presenting some data on cases of non-immune hydrops fetalis treated in the newly established Obstetrics Department of the Chinese University of Hong Kong at the Prince of Wales Hospital.

Female↗
PubMed1990

Maternal thyroid hormones and outcome of pre-eclamptic pregnancies.

Plasma concentrations of total and free thyroxine (TT4 and FT4), total and free triiodothyronine (TT3 and FT3), thyroid-stimulating hormone (TSH), plasma albumin and urate were measured in 39 proteinuric pre-eclamptic patients presenting before labour. Pre-eclamptic patients had significantly lower FT4 and higher TSH concentrations compared with values in third trimester normotensive pregnancies. There was a significantly higher frequency of lower TT4, TT3 and high TSH levels in the subgroup of pre-eclamptic patients who had low-birthweight babies. Thyroid hormone concentrations were not correlated with gestation at delivery or birthweight but, with the exception of FT4, were correlated with plasma albumin and urate concentrations. Plasma TSH correlated with birthweight and with plasma urate. The results suggest that mild biochemical hypothyroidism may be found in proteinuric pre-eclampsia, and the concentrations of TT4, TT3, FT3 and TSH may reflect the severity of pre-eclampsia.

Birth Weight↗
PubMed1990

Relationship between maternal antithrombin III and protein C/protein S levels before, during and after delivery.

The relationship between plasma levels of protein C, protein S and antithrombin III was examined in a group of normal pregnant Chinese women with singleton pregnancies to study the changes in the anticoagulant system in relation to pregnancy, labour and the puerperium. A significant correlation was found between protein C and antithrombin III both before labour and postpartum, and the ratio was close to unity. When the two groups are combined, a highly significant correlation was found (r = 0.758; p less than 0.001). The correlation is not observed at delivery when the ratio becomes very variable and in general greater than unity. The correlation between protein S and antithrombin III was 0.592 before labour and -0.532 at delivery, but both failed to reach statistical significance because of the small numbers. When postpartum concentration of protein C, protein S and antithrombin III is related to interval between sampling and delivery, significant correlation was found only with protein S. The results of this study suggest that the plasma level of protein C and probably protein S is correlated with that of antithrombin III during pregnancy, labour and the puerperium.

Antithrombin III↗
PubMed1990

A longitudinal study of changes in erythrocyte zinc concentration in hyperemesis gravidarum.

Erythrocyte zinc concentration and plasma thyroid hormones were measured in 32 patients admitted to hospital because of hyperemesis gravidarum. At presentation, 8 patients had elevated total and free thyroxine concentrations. The initial erythrocyte zinc concentration in these 8 patients was not different from the others, but in 5 of them, a transient drop in the erythrocyte zinc concentration was observed 2-12 weeks later, and which returned to normal towards the end of pregnancy. The lowest erythrocyte zinc concentration in the hyperthyroxinaemic group (171.0 +/- 31.7 mumol/l of RBC) was significantly lower than that of the normothyroxinaemic group (214.2 +/- 33.9 mumol/l of RBC) (p less than 0.01). This indicates that hyperthyroxinaemia in patients with hyperemesis gravidarum represents true hyperthyroidism, but is different from classical thyrotoxicosis in that the elevation of thyroid hormones is transient.

Carbonic Anhydrases↗
PubMed1990

Pregnancy outcome in women with labor-onset hypertension. Similar outcome between labor-onset hypertension and preeclampsia.

Labor-onset hypertension is a poorly documented category, and there is scanty information concerning the outcome of pregnancy in this condition. A retrospective study was performed to compare the pregnancy outcome of 36 patients with labor-onset hypertension (group A) with 36 patients with classical preeclampsia diagnosed before labor (group B) who were matched for parity and age. There was no difference in age, past history of hypertensive pregnancies or family history of hypertension between the two groups. The need for intrapartum hypertensive and anticonvulsant treatment as well as the outcome of pregnancy were similar in both groups. The only significant difference was that group A patients had lower maximum and booking systolic and diastolic pressures. The results indicate that labor-onset hypertension represents a late manifestation of the preeclampsia process, because these patients had lower blood pressure in pregnancy and would not be identified until intrapartum elevation of blood pressure satisfied the diagnostic criteria of preeclampsia.

Apgar Score↗
PubMed1990

Coagulation and anticoagulation systems in newborns--correlation with their mothers at delivery. Lower levels of anticoagulants and fibrinolytic activity in the newborn.

The neonatal period is probably the only time when a higher incidence of spontaneous thromboembolic complications may occur in the otherwise normal healthy individual, and this may be related to the activation of the coagulation system at the time of parturition. This study was performed to look at the newborn coagulation and anticoagulation systems and compare these with the changes in the maternal circulation in normal cases. Paired umbilical cord venous and maternal venous blood samples were obtained and plasma levels of protein C, protein S, antithrombin III, fibrinopeptide A, fibrinogen, plasminogen, and fibrinolytic inhibitory activity were measured. The maternal plasma level was significantly higher in all cases except for fibrinopeptide A which was similar, and for fibrinolytic inhibitory activity which was lower (p less than 0.05). A significant correlation exists between maternal and newborn protein C levels (p less than 0.02) and fibrinolytic inhibitory activity (p less than 0.05). The findings indicate that parturition leads to a similar degree of activation of the newborn coagulation system as shown by the fibrinopeptide A level. As their anticoagulants and fibrinolytic activity levels are lower and the fibrinolytic inhibitory activity is higher, the newborns are thus predisposed to thrombosis even in the absence of complications such as sepsis.

Antithrombin III↗
PubMed1990

Zinc and birth weight in uncomplicated pregnancies.

The relationship between zinc status and birth weight in uncomplicated pregnancies was studied in 59 nulliparous and 27 multiparous Chinese women with singleton pregnancies, delivered at term. Maternal and umbilical cord blood, maternal pubic hair and a segment of the umbilical cord were collected at delivery for analysis. The zinc concentration was significantly higher (p less than 0.0001) in the plasma of newborn infants (13.9 +/- 2.8 mumol/l) than in maternal plasma (9.3 +/- 2.2 mumol/l), while the converse was found in tissue (60.8 +/- 17.0 vs 208.1 +/- 96.2 micrograms/g, p less than 0.0001). There was no significant correlation between birth weight and either maternal or newborn plasma or tissue zinc concentrations. Parity had no significant effect on maternal or newborn zinc concentrations in tissue and plasma.

Birth Weight↗
PubMed1989

The effect of labour on prolactin and cortisol concentrations in the mother and the fetus.

Concentrations of prolactin and cortisol were determined in maternal and umbilical cord serum of women delivered by elective Caesarean section and by vaginal delivery. There was no difference in the concentration of prolactin in the two groups of women. Similarly, cord blood prolactin concentrations were not significantly different in the two groups. Cortisol concentrations in the women undergoing Caesarean section were similar to the vaginal delivery group before the onset of labour. However, there was a significant increase in cortisol concentration at delivery following labour. The cord blood cortisol concentration was significantly higher in the neonates delivered vaginally, and it correlated with the maternal cortisol concentration at delivery. The relevance of these findings is discussed.

Cesarean Section↗
PubMed1989

Fibrinopeptide A levels in maternal and newborn plasma.

Plasma fibrinopeptide A (FPA), a dynamic measure of intravascular coagulation, was determined in 70 healthy Chinese women during normal pregnancy, labour, delivery and the early puerperium and compared to a group of healthy non-pregnant adult controls. In the normal controls the plasma FPA level (mean +/- SD) was 1.43 +/- 0.46 ng/ml. During pregnancy and labour, the FPA levels were 3.05 +/- 0.98 ng/ml and 11.47 +/- 4.43 ng/ml, respectively, and it reached a peak of 32.95 +/- 11.66 ng/ml at parturition, then falling to 6.15 +/- 2.52 ng/ml in the early puerperium. All these levels were significantly higher (p less than 0.001) compared to controls. Fifteen of the 21 mothers with blood sampling during parturition also had umbilical cord blood taken for determination of FPA level. There was no significant difference between the maternal (34.07 +/- 10.12 ng/ml) and cord (31.06 +/- 12.67 ng/ml) plasma FPA levels. It is concluded that the hypercoagulable state in women during pregnancy and the puerperium is associated with increased intravascular coagulation activity, and that increased intravascular coagulation activity also occurs in the fetus during parturition. This observation may account for the increased risk of thrombotic disorders observed in pregnant and parturient women as well as in the newborn.

Female↗
PubMed1989

Plasma and erythrocyte zinc concentrations in pre-eclampsia.

Plasma and erythrocyte zinc concentrations were measured in 28 Chinese pre-eclamptic women and 28 controls matched for parity, race and gestation. There were no differences in either the plasma or erythrocyte zinc concentrations between pre-eclamptic and control groups, although the mean birth weight (p less than 0.001) and period of gestation (p less than 0.001) at delivery in the control group were significantly higher. In the pre-eclamptic patients, those delivering before 37 weeks or those who gave birth to low birth weight (less than 2500 g), babies had a significantly higher plasma urate concentration (p less than 0.02) compared to the pre-eclamptic patients with better fetal outcome. However, the plasma and erythrocyte zinc concentrations between these subgroups were not significantly different. Our results suggest that zinc deficiency is unlikely to play a significant role in pre-eclampsia in our patients, and that measurement of plasma and erythrocyte zinc concentrations is of doubtful clinical value in the management of pre-eclampsia.

Birth Weight↗
PubMed1989

Effect of folate supplement on pregnant women with beta-thalassaemia minor.

The effect of folate supplement on the haemoglobin concentration and outcome of pregnancy was studied in a group of Chinese women with uncomplicated beta-thalassaemia minor who delivered in our hospital between 1984-1987. The patients who received 5 mg folate daily showed a significant increase in the predelivery haemoglobin concentration, which was significantly higher than that in patients who received 0.25 mg daily. When the effect of parity was analysed we found that: multiparas were significantly older, had lower haemoglobin before delivery, and more of them required transfusion. Folate 5 mg daily significantly increased the predelivery haemoglobin concentration in both nulliparas and multiparas. It is concluded that folate 5 mg daily improves the haemoglobin concentration in pregnant women with beta-thalassaemia minor and that this should be prescribed.

Adult↗