R.K.H. Chin

Low birth weight and hyperemesis gravidarum.

A group of patients suffering from severe hyperemesis gravidarum is defined. In contrast to what is reported in the literature, these women gave birth to babies with lower birth weight when compared to the hospital population and also to women who had a milder degree of hyperemesis gravidarum. This indicates that the metabolic disturbance created by hyperemesis may have an adverse effect on the growth potential of the fetus.

Maternal thyroid hormones and outcome of pre-eclamptic pregnancies

Summary. 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. Preeclamptic 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.

Thyroid function in pre‐eclampsia

Summary. Thyroid function was studied in 24 proteinuric pre‐eclamptic patients and 24 gestation‐matched controls. The pre‐eclamptic patients had significantly lower mean total (TT4) and free thyroxine (FT4), and thyroxine‐binding globulin (TBG) concentrations, and the concentration of thyroid‐stimulating hormone was significantly higher. The mean total triiodothyronine (TT3) concentration, however, was similar to the controls. This is at variance with the classical low T3 syndrome reported previously for pre‐eclamptic patients. Compared to the controls, 33·3% and 29·2% of the pre‐eclamptic patients had low TT4 and TT3 concentrations respectively. Pre‐eclamptic patients with low TT4/ TT3 had significantly higher plasma urate concentrations. Thyroid hormone concentrations may reflect the severity of pre‐eclampsia.

Renal Function in the Newborn

The maternal and newborn renal function in 84 normal pregnant women delivering at term was investigated. There was no difference between maternal and newborn plasma concentrations of urea (3.9 ±

The significance of proteinuria in pre-eclampsia; proteinuria associated with low birth weight only in pre-eclampsia

To examine the significance of proteinuria in pre-eclampsia, we studied 87 nulliparous patients in whom pre-eclampsia was diagnosed clinically and whose blood pressure and urine findings returned to normal after delivery. There was no difference in the gestation at diagnosis, highest systolic and diastolic blood pressures before treatment/delivery, or the number given antenatal hypotensive therapy between patients with proteinuria (group A, n = 46) and without proteinuria (group B, n = 41). Group A patients had higher plasma urea concentration (p less than 0.02), but similar creatinine and urate concentrations to group B patients. Group A patients had a higher rate of induction of labour (p less than 0.04) and Caesarean section before labour (p less than 0.04), and the mean gestation at delivery as well as the birth weight were less (p less than 0.03 and p less than 0.004, respectively). The results suggest that proteinuria in pre-eclampsia is associated with more severe fetal involvement and growth retardation only, but not with an increased severity of the maternal condition such as hypertension and a higher plasma urate concentration.

Is X-ray pelvimetry useful in a trial of labour after caesarean section?

In a trial of labour after caesarean section, X-ray pelvimetry has generally been regarded as an important part in the evaluation of patients before a decision is made. A review of 445 patients with trial of labour has shown that although the measurements of the pelvic inlet were greater in patients who delivered vaginally, the incidence of successful trial was not related to the measurements of the pelvis. Maternal height was also unrelated to the outcome. Only a history of previous vaginal delivery was predictive of a successful trial. The results suggest that X-ray pelvimetry is not necessary in the majority of patients if the past obstetric history and the clinical assessment are in favour of a successful trial. It is only useful when there is doubt and in this case both a lateral and an antero-posterior film are necessary as the obstetric conjugate alone was unreliable in predicting the transverse diameter of the inlet as well as the outcome.

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

SummaryPlasma and erythrocyte zinc concentrations in 45 proteinuric pre-clamptic 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.

Plasma Zinc Concentration and Thyroid Function in Hyperemetic Pregnancies

Low zinc concentrations in plasma have been reported in pregnancy complications such as pre‐eclampsia and intra‐uterine growth retardation, as well as in non‐pregnant individuals with gastrointestinal and eating disorders. The present study looked at the plasma zinc concentration in hyperemetic and normal pregnant women at the same stage of gestation, as well as total thyroxin concentration in these two groups, since abnormal thyroid function is a common phenomenon in hyperemetic women. No difference in plasma zinc concentration was found between normal and hyperemetic women, which suggests that hyperemesis gravidarum is not associated with a low plasma zinc concentration. Hyperemetic women did have, however, significantly higher total thyroxin concentrations, and on further examination, a significant correlation was found between plasma zinc concentration and total and free thyroxin, free tri‐iodothyronin, and human chorionic gonadotropin. The significance of our findings is discussed.

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.

Effects of Intrapartum Intravenous Infusion of 5% Dextrose or Hartmann's Solution on Maternal and Cord Blood Glucose

The effects of intrapartum infusion of dextrose or Hartmanns solution on maternal and cord blood glucose were studied. Patients with and without infusion of intravenous fluids during labor were randomly selected and allocated to one of three groups. Group I received 5% dextrose solution as a vehicle for oxytocin (dextrose group), group II received Hartmanns solution (Hartmann group) and group III did not receive any intravenous infusion (control group). Each group consisted of 16 patients. Routine labor ward procedures were followed. Maternal and cord blood samples were taken at delivery. Maternal blood glucose concentrations were significantly lower in the Hartmann group than in the dextrose and control groups, showing a dilution effect of Hartmanns solution. Cord blood glucose concentrations did not differ significantly between the three groups, indicating that maternal infusion of dextrose or Hartmanns solution in routine intrapartum management would have no adverse effects on fetal blood glucose.