Serial serum ferritin and other hematological parameters in normal Nigerian primigravidae

Serial hematological indices using Coulter Counter and serum ferritin using radioimmunoassay techniques were determined in 20 healthy Nigerian primigravidae with hemoglobin genotype AA. PCV fell significantly (P less than 0.001) to a minimum value at 28 weeks that was 6% lower than the mean value at 8 weeks postpartum. PCV at 36 weeks was still significantly (P less than 0.001) lower than the post partum value. There was an insignificant but progressive increase in MCV values throughout pregnancy. Changes in MCH and MCHC were insignificant. Ferritin levels in both the non-pregnant and pregnant subjects were high and probably reflected the high iron content of Nigerian foods. Though the cord serum ferritin level was significantly higher (P less than 0.001) than maternal ferritin at delivery there was no significant correlation between the two.     

Criteria for the oral glucose tolerance test in pregnant and non-pregnant Nigerian women

In order to establish diagnostic criteria for detection of abnormal oral glucose tolerance test (OGTT) in pregnant and non-pregnant Nigerian women, the test was performed in 25 non-pregnant and 60 pregnant non-diabetic women at various trimesters of pregnancy. The upper limit of normal plasma glucose was the same as that from caucasian populations with respect to the fasting values but much less at 60 and 120 min. When compared to the non-pregnant controls, fasting plasma glucose was significantly lower during pregnancy, however, there was no change in glucose tolerance during pregnancy. The possible reasons for these observations are discussed and it would appear that our criteria would be the ideal ones to use for clinical purposes in Nigerian women.     

Plasma concentrations of motilin and somatostatin are increased in late pregnancy and postpartum.

OBJECTIVE: To examine plasma levels of motilin and somatostatin throughout pregnancy. DESIGN: Prospective observational study. SETTING: University Hospital, Norway. SUBJECTS: Eight healthy pregnant women (aged 24-38 years) six of them primigravidae and eight healthy non-pregnant women of similar age with ovulatory menstrual cycles. INTERVENTIONS: In the pregnant women blood samples were obtained at 4-week intervals from 8 weeks gestation throughout pregnancy and again at 5 days and 28 days postpartum. In the non-pregnant controls blood samples were obtained on cycle days 4, 7, 10, 13, 14, 15, 18, 21 and 24. MAIN OUTCOME MEASURES: Plasma levels of motilin and somatostatin. RESULTS: Plasma concentrations of both motilin and somatostatin rose continuously during pregnancy, and motilin levels increased still further to a peak of 165.1 (SE 35.8) pmol/l at 5 days postpartum. Plasma motilin levels were significantly higher during the third trimester and at 5 days postpartum compared with non-pregnant controls (P less than 0.0001). The highest plasma somatostatin levels were found at 40 weeks gestation and at 5 days postpartum (mean 32.1 SE 1.1 pmol/l). Somatostatin levels were significantly higher during the second and third trimester and the postpartum period compared with levels in the follicular phase of the non-pregnant controls (P less than 0.0001). CONCLUSIONS: Circulating levels of motilin cannot play a major role in the relaxation of the gut in pregnancy, but somatostatin may play a part in regulating motility.     

Angiotensin II levels in hypertensive and normotensive pregnancies

We measured circulating angiotension II by radioimmunoassay in women with pregnancy-induced hypertension (n = 54), and compared these values with those obtained in women with normal pregnancy (n = 18) and in non pregnant women (n = 20). Pregnant women had statistically significantly higher plasma angiotensin II [mean (SD): 41.3 (12.6) pg/ml] than non-pregnant women [29.2 (11.3) pg/ml; P less than 0.004]. Angiotensin II concentrations in women with pregnancy-induced hypertension [mean (SD): 31.7 (16.2) pg/ml] were, on average, 25% lower than in normal pregnancy (P less than 0.003) and resembled those obtained in non-pregnant women. The lowest angiotensin II levels were found in women with more severe forms of pregnancy-induced hypertension, such as proteinuric or superimposed pregnancy-induced hypertension. Review of the published studies on angiotensin II and our data suggest that the conflict among studies on angiotensin II levels in pregnancy-induced hypertension is largely due to the heterogeneity of the study populations in the various reports.     

Echocardiography during pregnancy--longitudinal studies in primigravidae

As a result of hormonal changes processes of adaptation of the cardio-vascular system occur during pregnancy. These regulative changes are the basis for the present echo-cardiographic study which was made under standardized conditions with healthy primigravidae (n = 20) compared to nulligravidae (n = 24). Besides blood pressure and heart frequency dimension and volume sizes of the left ventricle (LV) as well as the LV-weight of muscle and the peripheral vascular resistance were analysed. As result significant increases from the 15th to the 35th week of pregnancy (SSW) could be found for the following parameters: heart frequency, arterial blood pressure, endosystolic volume of the left ventricle, cardiac output, left ventricular weight of muscle (p less than 0.01) endosystolic diameter of the left ventricle, enddiastolic volume of the left ventricle and heart index (p less than 0.05). The peripheral resistance was continuously decreased in the course of pregnancy (p less than 0.01). Compared to non-pregnant women the following parameters showed significantly higher values: heart frequency, cardiac output and heart index (p less than 0.01). The peripheral resistance was significantly lower in pregnant women compared to non-pregnant women (p less than 0.01). From the results the conclusion can be drawn that with statistic certainty echocardiography records adaptive processes of the circulation regulation relative to pregnancy and enables a separation in the groups of pregnant and non-pregnant women.     

A prospective study of plasma angiotensin-converting enzyme in normotensive primigravidae and their infants

Plasma angiotensin-converting enzyme (ACE) has been measured prospectively throughout pregnancy, at delivery and in the puerperium in 18 normotensive primigravidae and their infants. Plasma ACE was consistently lower during pregnancy than in comparable, non-pregnant controls, but rose progressively from about 30 weeks to term. At vaginal delivery maternal and fetal ACE levels did not differ significantly. There was a steady increase in maternal ACE activity up to 6 weeks post partum, when the levels were not significantly different from non-pregnant controls. No correlation could be found between plasma ACE and plasma renin activity or concentration, or plasma AII. Plasma aldosterone increased in parallel with ACE during the last ten weeks of pregnancy.     

Blood pressure, plasma osmolarity and oedema in pregnancy

Summary. Relations of mean arterial pressure to age, parity, plasma osmolarity, sodium and albumin were examined in normal non-pregnant, normal pregnant and pre-eclamptic Nigerian women. Mean arterial pressure showed a positive correlation with age in non-pregnant subjects, but not in normal pregnant or pre-eclamptic women. There was no siginficant correlation of mean arterial pressure with parity, plasma sodium or albumin in any of the three groups. A weak positive correlation was found between mean arterial pressure and plasma osmolarity in non-pregnant women and, although this was absent in normal pregnancy, it reappeared as a significant negative correlation in pre-eclampsia. These observations were considered, with special reference to osmotic aspects of the changes involved, and biophysical aspects of oedema are discussed. It is suggested that the osmotic properties of interstitial fluid albumin play a key role in the development of both physiological and pathological oedema in pregnancy.     

Plasma corticotrophin-releasing factor (CRF) in normal pregnancy

Corticotrophin-releasing factor (CRF) was measured directly in maternal plasma using an immunoradiometric assay (IRMA). In the first and second trimester CRF levels were within the non-pregnant range (mean 15 pg/ml). A total of 72 women was followed sequentially from 28 weeks until delivery and CRF levels rose from a median of 20 pg/ml at 28 weeks to 1320 pg/ml at 40 weeks and 1732 pg/ml during labour. There was a strong correlation (rs = 0.81, P less than 0.001) between gestational age and CRF levels. The rate of rise of CRF (pg/ml) per week was associated with weight gain (rs = 0.36, P less than 0.05) but with no other obstetric variable. There was an association between umbilical cord and maternal plasma CRF levels (rs = 0.54, P less than 0.01).     

Platelet angiotensin II binding sites in normotensive and hypertensive women

Specific binding of angiotensin II (AII) to platelets was measured in 89 women, 25 nulliparous non-pregnant women and 64 primigravida in the third trimester of pregnancy. There was significantly lower binding in the 25 pregnant women who were normotensive (2.3 fmol/10(9) cells) when compared with the non-pregnant women (9.0 fmol/10(9) cells P less than 0.001). Significantly higher platelet AII binding levels were found in the 39 women who had pregnancy induced hypertension (PIH) (5.5 fmol/10(9) cells) when compared with the 25 normotensive pregnant women (P less than 0.001). Of the 39 women with PIH, platelet AII binding was higher in the 23 women who had pre-eclampsia (7.0 fmol/10(9) cells), when compared with the 16 who had non-proteinuric PIH, (4.6 fmol/10(9) cells) although the difference was not statistically significant (P less than 0.04). The pressor response to AII is also diminished in pregnancy, yet less so if pregnancy induced hypertension develops. Platelets may provide a readily accessible tissue with which to study AII responsiveness in pregnancy.     

Red cell mass during and after normal pregnancy.

Red cell mass, derived from plasma volume and haematocrit, was calculated serially in 45 healthy women during pregnancy and 4 to 6 months after delivery. Compared to the non-pregnant, postpartum value there was a reduction of approximately 100 ml at 12 weeks gestation. An increase in red cell mass occurred thereafter: at 36 weeks gestation values 180 ml greater than the non-pregnant were found. Iron and folic acid supplements almost doubled this increment to 349 ml of red cells.     

A randomized placebo-controlled study of the effect of low dose aspirin on platelet reactivity and serum thromboxane B2 production in non-pregnant women, in normal pregnancy, and in gestational hypertension.

OBJECTIVE: To investigate the effect of 60 mg aspirin daily on platelet reactivity and prostaglandin production in various groups of patients. Similar regimens, which are thought to act through inhibition of platelet thromboxane production, are currently undergoing clinical assessment for the prevention of pre-eclampsia and intrauterine growth retardation. DESIGN: A prospective randomized placebo controlled study. SETTING: University Hospital, Nottingham. SUBJECTS: 12 non-pregnant female volunteers, 18 normal primigravidae before 16 weeks gestation and 16 pregnant women admitted with gestational hypertension (GH) at a mean gestation of 38 weeks. INTERVENTIONS: In the non-pregnant women blood samples were taken before and after a 10-day course of 60 mg aspirin daily. The primigravidae had blood samples taken at 16 weeks and then they were randomized to receive either 60 mg aspirin daily or a matched placebo. Further blood samples were obtained at 28, 32 and 36 weeks. MAIN OUTCOME MEASURES: Changes in platelet reactivity and release reaction, and serum thromboxane production, were estimated in whole blood. RESULTS: 60 mg aspirin daily significantly inhibited cyclo-oxygenase dependent platelet aggregation, release reaction and serum thromboxane production in non-pregnant and pregnant women, and in women with GH (P less than 0.01). When adrenaline was used as the aggregating agent, the cyclo-oxygenase pathway was recruited in the increased reactivity seen in the third trimester of normal pregnancy, and was sensitive to inhibition by low dose aspirin. CONCLUSION: Low dose aspirin would appear to be an appropriate agent for the inhibition of platelet reactivity associated with hypertensive pregnancy.     

Title Index to Volume 23

The responses of plasma renin activity (PRA), plasma aldosterone concentration (PAC), urine aldosterone excretion (UA) and plasma volume (PV) to dietary sodium manipulations were examined in 50 second and 40 third trimester primigravidae. PRA, PAC and UA fell significantly following one week on a high-salt (HS) diet and rose significantly following a low-salt (LS) diet at both stages. PRA values for pregnant subjects following intravenous saline loading at the completion of their HS diet were seven to eight-fold greater than for six non-pregnant subjects who had the same studies.

The absolute values for PRA, PAC, UA and UNa. V, and the individual changes in each of these parameters following dietary manipulations were signficantly interrelated during both trimesters. The relationship between change in UNa.V (ΔNa) and change in PRA (ΔPA) was exponential., there was an increase in PRA independent of ΔNa during the second, but not the third trimester, and the sensitivity of ΔPA to ΔNa was greater in the third trimester.

The plasma volume changed slightly, but significantly (p<0.001) in response to both diets in the second trimester but was more closely maintained during the third trimester. These results demonstrate that the renin-aldosterone system responds appropriately to changing sodium intake during pregnancy to maintain plasma volume constancy, that PRA is not suppressible to non-pregnant values despite the combination of dietary and intravenous sodium loading, and that significant differences in the dynamics of this system are present between trimesters     

Predictive value of increased plasma levels of fibronectin in gestational hypertension

Blood pressure, proteinuria, and plasma fibronectin and plasminogen activator inhibitor-1 levels were measured in 120 apparently healthy normotensive primigravid women during the first, second, and third trimesters of pregnancy and 2 days post partum. Thirty-two women developed hypertension (diastolic blood pressure greater than or equal to 90 mm Hg) that in 17 women was associated with proteinuria (greater than 0.3 gm/day). Fibronectin levels were 83% +/- 22% of normal (mean +/- SD) during the first trimester and 75% +/- 20% at term in the healthy women but increased from 94% +/- 36% to 187% +/- 36% in the women who developed gestational hypertension (with or without proteinuria) (p less than 0.0001). Plasminogen activator inhibitor-1 levels increased from 26 +/- 19 ng/ml to 110 +/- 86 ng/ml in healthy women and from 32 +/- 35 ng/ml to 290 +/- 90 ng/ml in hypertensive women (p less than 0.001). Increased levels of fibronectin at 25 to 36 weeks of pregnancy (greater than or equal to mean + 2 SD of the healthy women, or greater than 140%) were found in 31 of the 32 women with gestational hypertension with or without proteinuria and in 5 of the 88 healthy women (sensitivity 96%, specificity 94%). Fibronectin levels increased 3.6 +/- 1.9 weeks earlier than the onset of hypertension and/or proteinuria. Increased levels of plasminogen activator inhibitor-1 at 25 to 32 weeks (greater than or equal to 280 ng/ml) were found in 16 of the 32 women who developed gestational hypertension with or without proteinuria and in 4 of the 88 healthy women (sensitivity 50%, specificity 95%). We conclude that increased fibronectin levels are the best predictor of gestational hypertension with or without proteinuria and that its level in plasma increases several weeks before the development of hypertension.     

Hyperhomocysteinaemia: a risk factor for preeclampsia?

Preeclampsia represents one of the most frequent complications of pregnancy, however, little is known about its aetiology. Damage of the endothelial layer lining the blood vessel wall is thought to play an important role in the pathophysiology of preeclampsia, accordingly, mild hyperhomocysteinaemia has been reported to be more prevalent among preeclamptic women. Therefore, we investigated the role of hyperhomocysteinaemia in preeclampsia by measuring plasma levels of homocysteine and studying the prevalence of the 677(C-->T) polymorphism in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene, which may lead to reduced MTHFR enzyme activity and subsequently to higher plasma homocysteine levels.Plasma samples of 10 healthy non-pregnant women, 10 normotensive pregnant women, and 20 women with preeclampsia were analysed for total homocysteine levels by high performance liquid chromatography. Furthermore, 167 Dutch non-pregnant women previously hospitalised for preeclampsia and 403 population-based controls were analysed for the 677(C-->T) polymorphism by polymerase chain reaction followed by restriction fragment length polymorphism analysis (PCR/RFLP).In normotensive pregnancy homocysteine levels were lower compared with levels in healthy non-pregnant controls (8.4 versus 13.7micromol/l, P<0.001). Women with preeclampsia showed higher concentrations than women during normotensive pregnancy (13.3 versus 8.4micromol/l, P<0.02). However, levels of homocysteine in preeclampsia were comparable to those found in healthy non-pregnant women. PCR/RFLP showed no significant difference in the incidence of the 677(C-->T) polymorphism in the MTHFR gene between preeclamptic women with or without HELLP syndrome and controls (13 and 9% homozygous for the less common T-allele, respectively; OR 1.5, 95% CI 0.8-2.6, P=0.17).In contrast with previous reports, we cannot confirm that mild hyperhomocysteinaemia is a risk factor for preeclampsia. Pregnancy induced hyperhomocysteinaemia found in preeclampsia might better be explained by fluctuations in plasma volume than by the presence of the 677(C-->T) polymorphism in the MTHFR gene.     

Zinc and copper concentration in plasma of pregnant women in Nigeria

The concentration of plasma zinc and copper were determined by atomic absorption spectrophotometry in 58 Nigerian women at various times in pregnancy and compared with those of 11 non-pregnant controls. The results showed 67.5% decrease in zinc and 100% increase in copper over non-pregnant levels at the end of pregnancy. The mean plasma zinc levels were appreciably lower and copper the same as published values for Caucasian women at similar periods in pregnancy. Furthermore, there was no correlation between plasma zinc and copper and neonatal birthweight. We conclude that (1) a significant proportion of pregnant women in Nigeria have biochemical hypozincemia; (2) this hypozincemia is not responsible for fetal growth retardation in this population and (3) there is at present no justification for giving routine zinc supplementation to pregnant women in Nigeria.     

Elevated plasma prolactin concentration in cholestasis of pregnancy.

The plasma concentrations of prolactin and estradiol-17 beta were measured by specific radioimmunoassays in 150 women with normal pregnancies and 76 women with cholestasis of pregnancy. At 33 to 34 weeks of gestation plasma prolactin concentrations were 187 +/- 23 ng/ml (mean +/- S.E.M.) for normal pregnancy and 341 +/- 38 ng/ml for cholestasis (p less than 0.001). At 35 to 36 weeks they were 254 +/- 24 and 355 +/- 26 ng/ml (p less than 0.01), and at 37 to 38 weeks 175 +/- 14 and 365 +/- 34 ng/ml (p less than 0.001), respectively. Higher prolactin levels in the cholestasis group were not related to differences in plasma estradiol-17 beta concentrations. No correlation was found between plasma prolactin and serum aminotransferase levels, or between prolactin levels and placental weight. The mechanisms by which plasma prolactin levels become elevated in cholestasis of pregnancy remain to be elucidated.     

Increased red-cell sodium-lithium countertransport activity and urinary 11-dehydrothromboxane B2 during pregnancy]

The activity of Na-Li countertransport (CT), a marker of the risk of essential hypertension, was determined in 55 primigravid women during pregnancy, together with urinary 11-dehydro-thromboxane B2 (11-dehydro-TXB2) as a marker of thromboxane A2 synthesis. The mean Na-Li CT (mean +/- SEM) value was increased significantly at 20 weeks gestation and thereafter, and reached higher levels in late pregnancy than in non-pregnant controls (0.31 +/- 0.02 vs. 0.21 +/- 0.01mmol per hr per liter RBC, p less than 0.05). Fifty five primigravid women could be divided into two groups, depending upon Na-Li CT activity either higher or lower than the value of 0.25mmol per hr per liter RBC at any time in the pregnancy up to term. At 20 weeks gestation all but one of 13 women in the lower-activity group had Na-Li CT activity less than 0.20 mmol per hr per liter RBC, and none developed PIH, whereas out of 42 women in the higher-activity group, all but one had Na-Li CT activity more than this value, and 8 developed PIH. Urinary 11-dehydro-TXB2 increased as pregnancy progressed, maximum levels being attained in women at term, about 3 times higher than in controls (4.19 +/- 0.35 vs. 1.36 +/- 0.10 ng per mg creatinine, p less than 0.05). Although the formation of thromboxane A2 was reported to be higher in pregnancy complicated by hypertension, no significant difference existed in the levels of 11-dehydro-TXB2 between women with PIH and women with uncomplicated pregnancy.(ABSTRACT TRUNCATED AT 250 WORDS)     

Fetal acidosis in labour: a prospective study on the effect of parity

The effect of parity on intrapartum fetal scalp pH was investigated in 6466 patients in labour with a live fetus who were delivered in 1987. 350 (5.4%) required fetal scalp blood sampling for pH (FBS), 236 primigravidae (10.4%) and 114 multigravidae (2.7%) (P less than 0.001). Fetal acidosis (pH less than 7.20) was detected in 35 patients, 27 primigravidae (11.4%) and 8 multigravidae (7.0%) (P less than 0.001). The incidence of intrapartum acidosis in the 2275 primigravidae and the 4191 multigravidae was 1.2 and 0.2% respectively (P less than 0.001). The two deaths from birth asphyxia and three cases of neonatal seizures occurred in primigravidae. In primigravidae requiring FBS, fetal acidosis was not associated with the use of oxytocin or with increased duration of labour. Neonatal seizures were more common overall in primigravidae than in multigravidae and more common in patients requiring FBS than in those not requiring FBS (P less than 0.05). The higher incidence of FBS, fetal scalp acidosis and neonatal seizures in primigravidae has important implications for intrapartum fetal monitoring.     

Assessment of thyroid functions and thyroid volume in normal pregnant Egyptian females

Abstract

The normal range of thyroid functions during pregnancy differs between ethnic groups. This study assessed the thyroid functions in normal pregnant Egyptian females. Thyroid peroxidase antibodies (TPO Abs) and thyroid volume were also assessed. The study included 150 normal pregnant Egyptian females, recruited from Cairo University Hospital Antenatal Care Clinic (50 in each trimester), with 40 age-matched non-pregnant females, as a control group. Serum thyroid stimulating hormone (TSH) and TPO Abs were measured. Thyroid volume was assessed by ultrasonography. TSH ranges were 0.21–1.7, 0.52–3.2 and 0.72–2.6 mIU/L during first, second and third trimesters, respectively. The mean TSH level in pregnant females was significantly lower than that of non-pregnant women (1.2?±?0.7 vs 2.7?±?0.9 mIU/L, p?<?.001). TPO Abs were significantly higher in the first trimester compared to both second and third trimesters (p?<?.001 for both). Thyroid volume of pregnant females was non-significantly higher than that of non-pregnant control subjects (p?=?.126). A significant positive correlation was found between thyroid volume and body mass index in pregnant females (p?<?0.001). Our study established trimester-specific reference ranges for thyroid functions in normal pregnant Egyptian females. A larger population-based study would help to confirm those ranges. Thyroid volume was non-significantly higher than that of non-pregnant control subjects.     

Immunoreactive prostacyclin and thromboxane metabolites in normal pregnancy and the puerperium

Prostacyclin and thromboxane have been implicated in the pathophysiology of several disorders of pregnancy, but there is little information on concentrations of these prostaglandins in normal pregnancy. The aim of our study was to determine the range of values throughout normal pregnancy and the puerperium and to compare this with concentrations in normal non-pregnant women. Measurement was by radioimmunoassay of prostacyclin and thromboxane metabolites. We observed a significant difference in prostacyclin metabolites in the first trimester, (mean 19.9, SEM 0.96 pg/ml) compared with the normal non-pregnant group (mean 15.9, SEM 0.68 pg/ml). There were no significant differences between values in the normal non-pregnant group and those in the second and third trimester or postnatally. The increase in prostacyclin in the first trimester may be associated with placentation and physiological vasodilation, and insensitivity to angiotensin II seen in early pregnancy. We noted a significant reduction in thromboxane metabolites in the second (mean 133, SEM 14.9 pg/ml) and third (mean 123, SEM 10.7 pg/ml) trimesters and the puerperium (mean 119, SEM 6.3 pg/ml) compared with the values in the normal non-pregnant group (mean 142, SEM 4.9 pg/ml). This may be due to increased platelet stability or decreased thromboxane synthesis.