Serum Human Placental Lactogen Research Articles

The effect of smoking on serum human placental lactogen levels

Serial serum samples (162) were drawn weekly from normal pregnant women (53) during the last month of gestation and measurements were made of the human placental lactogen (HPL) content. The women were interviewed as to their smoking habits and divided into nonsmokers (32) and smokers of from one to two packages of cigarettes per day (21). The infant birth weight and placental weights were not significantly different. The HPL levels were elevated in the women who smoked and the differences were significant at the thirty-sixth and thirty-eight weeks. The importance of this in interpreting HPL as a placental function test and in terms of the biology of placental function and the control of protein hormone synthesis is emphasized.

HCG, HPL, oestradiol, progesterone and AFP in serum in patients with threatened abortion.

The predictive value of various biochemical methods for monitoring early risk pregnancies has been compared in 65 cases of threatened abortion. Estimation of human chorionic gonadotropin (HCG), human placental lactogen (HPL), progesterone, oestradiol and alpha-fetoprotein (AFP) in serum were made by radioimmunoassays. Values below the normal range predicted abortion in 79, 81, 89, 92 and 38 per cent of patients, while normal values confirmed continuation of pregnancy with an accuracy of 71, 61, 60, 68 and 30 per cent respectively. Thus predictions from oestradiol and progesterone were at least as reliable as those from the protein hormones, while AFP proved to be unsuitable for this purpose. Combination of two variables gave even more reliable results. Due to individual and diurnal variation, however, abortion in the third and fourth month could not be definitely assumed at values above 5 IU HCG/ml, 5 ng progesterone/ml or 200 pg oestradiol/ml.

Direct radioimmunoassay for serum estriol during pregnancy.

I describe an assay for serum estriol during pregnancy, which does not require prior extraction or chromatography of the serum. Fifty microliters of 20-fold diluted serum can be assayed to detect as little as 20 pg of estriol. For a 20 mug/liter serum estriol concentration the CV was 16%; for 100 mug/liter concentration it was 5%. There was no significant interference by serum "binding" proteins. The assay measures unconjugated estriol, estriol conjugated with either sulfate or glucuronide at the 3' position, and a portion of the estriol 16 alpha (beta-D-glucuronide). Serum estriol concentrations increase during gestation from a low at 20 weeks of less than 10 mug/liter to a high of 100-150 mug/liter at term. Serum estriol values correlate well with those for urinary total estrogens and with values for human placental lactogen in serum at various gestational ages.

Serum Human Placental Lactogen (HPL) Levels in Patients with Intact Hydatidiform Mole

Serum human placental lactogen (HPL) levels in forty cases of intact hydatidiform mole were measured by radioimmunoassay. The HPL values were generally lower than normal pregnancies of the corresponding period of gestation. However, normal and occasionally higher than normal values were observed in a few cases. Serum HPL level alone is of some clinical use in the diagnosis of hydatidiform mole. When combined with human chorionic gonadotropin (HCG), a low HPL/HCG ratio for the corresponding period of amenorrhoea is a useful index in the diagnosis of hydatidiform mole.

The Effect of Intra‐Amniotic Injection of Hypertonic Urea on Human Placental Lactogen (HPL) Secretion

Segal, S., Ben‐David, M., Anteby, S. O. and Polishuk, W. Z. (Depts. of Obstetrics & Gynecology and Pharmacology, Hadassah Medical Center, Jerusalem, Israel). The effect of intra‐amniotic injection of hypertonic urea on human placental lactogen (HPL) secretion.Int J Gynaecol Obstet 13: 193–196, 1975.Serum human placental lactogen (HPL) levels were studied in 27 women with normal pregnancies in their second trimester in whom abortion was induced by intra‐amniotic (IA) hypertonic urea. The levels of HPL remained stable during the procedure and up to the delivery of the placenta. The condition of the fetus (dead or alive) or the injection‐abortion interval did not affect HPL levels. It is thus concluded that HPL secretion is not impaired by the hypertonic urea, that it plays no role in initiation of uterine contractions, and whatever damage induced by the hypertonic urea solution does not affect HPL activity.

Distribution of human placental lactogen in the last half of normal and complicated pregnancies

Serum human placental lactogen (HPL) was measured by a radioimmunoassay technique in 7,443 samples obtained from 1,814 pregnant women beyond their twentieth week of gestation. The pattern demonstrated by the 3,014 samples from 804 normal women confirmed the fact that abnormally low HPL values can be defined by the F-D zone (<4 μg per milliliter after 30 weeks of gestation) and these rarely occur (1.4 per cent) in normal pregnancies. The patterns in pregnancies complicated by Rh sensitization (38 women; 156 samples), diabetes mellitus (23 women; 248 samples), and hypertensive toxemia (949 women; 4,025 samples) were also studied. The major factor which appears to lower HPL values is vascular disease. In the toxemia group HPL values were more frequently depressed with multiparity and severe hypertension (BP>160/110). There was no relation noted between the presence of albuminuria in primiparous toxemia and the level of HPL in maternal serum. It would appear that the measurement of HPL in women with potential vascular disease will help to identify those with concurrent abnormal placental function.

Serum human placental lactogen hormone concentration in the second half of pregnancy determined by a simple immunoelectrophoretic technique.

ABSTRACT By a simple rocket immunoelectrophoretic method the 90 % normal range of serum human placental lactogen hormone (HPL) in the second half of pregnancy was determined in 436 normal pregnant women. The mean half life of HPL after delivery of normal infants determined in 5 patients was found to be 14.6 min (range 13.2–16.4 min). A close correlation was found between serum HPL and serum progesterone (r = 0.75). No circadian rhythm was found.

Effect of dexamethasone on serum levels of human placental lactogen during the last trimester of pregnancy.

SummaryTwelve mothers were given orally 1.0 mg. of dexamethasone four times daily for 6 to 12 days during the last trimester of pregnancy. Serial serum human placental lactogen (HPL) determinations were made by radioimmunoassay before and during the treatment. Dexamethasone did not change the HPL level.

Glucose-insulin interaction and the modulation of human placental lactogen (HPL) secretion during pregnancy.

SummaryIn order to define metabolic factors which control human placental lactogen (HPL) secretion two types of experiment have been conducted: (a) hypoglycaemia was induced by intravenously‐injected insulin in 21 normal women in late pregnancy; and (b) a sustained hyperglycaemia was obtained by glucose infusion in six normal women in late pregnancy. Serum HPL was determined using an immunosorbent antibody radioimmunoassay procedure. Blood glucose was estimated in both experiments and plasma immunoreactive insulin in the second. The results show an inverse relationship between blood glucose and serum HPL concentrations. Hyperglycaemia caused the HPL level to fall and conversely insulin‐induced hypoglycaemia caused it to rise. Moreover, declining blood glucose levels after the cessation of a glucose infusion were accompanied by an increase in HPL comparable to that seen during frank hypoglycaemia.

Intrauterine Fetal Growth Retardation: A Comparison of Human Placental Lactogen Urinary Oestriol and Biparietal Diameter Measurements

Forty-two ‘at risk’ pregnancies were serially monitored by sonar biparietal cephalometry, 24 h urinary oestriol assays and determination of serum human placental lactogen. The results were assessed by a scoring system, and it was found that a combination of sonar cephalometry and 24 h urinary oestriol assays gave the most reliable prediction of intrauterine growth retardation.

Human placental lactogen (HPL) in serum in complicated early pregnancy.

SummaryThe clinical value of maternal serum HPL concentrations determined by radio‐immunoassay in complicated early pregnancy was studied between the 6th and 20th weeks of pregnancy. The subjects were 203 normally pregnant women and 188 whose pregnancy was complicated by uterine bleeding. In threatened abortion where the pregnancy continued successfully (102 patients) the HPL level was generally similar to that in normal pregnancy and showed a pattern of increase in serial determinations. In complicated pregnancies with an unsuccessful outcome (blighted ovum 19, incomplete abortion 42, and missed abortion 25) HPL values were low and decreased in serial samples. A single HPL determination seemed to be a sufficiently reliable index of viable pregnancy from the 14th week onwards, but before that serial HPL samples would seem to be needed.

Human placental lactogen (HPL) levels in maternal serum during abortion induced by intra- and extra-amniotic injection of prostaglandin F2a.

SummaryHuman placental lactogen (HPL) concentrations in maternal serum were measured by double antibody radioimmunoassay in 25 patients who were undergoing abortion by intra‐ and extra‐amniotic injection of prostaglandin F2α (PGF2α) and by extra‐amniotic injection of hypertonic saline in the first and second trimesters of pregnancy. The injection of 150 ml. of 20 per cent NaCl did not change the HPL level but the extra‐amniotic injection of 5 to 6 mg. of PGF2α and the intra‐amniotic injection of 20 to 25 mg. of PGF2α decreased the serum HPL level significantly (p&lt;0.01) in the two hours after the injections. PGF2α administered by intrauterine routes appeared to have a direct effect on the placental synthesis and/or the secretion of HPL in early pregnancy.

Hormone and enzyme levels in normal and complicated pregnancy

A retrospective study of 48 high-risk pregnancies has been made. The values of two hormonal and two enzyme assays have been compared in assessing placental function. Neither of the enzyme levels (serum heat-stable alkaline phosphatase and serum diamine oxidase) were found to be of clinical value. Serum human placental lactogen levels were consistently decreased in essential hypertension and in pregnancies terminating in stillbirth. Urinary estriol estimation proved to be more reliable, especially in monitoring the “light-for-dates baby” pregnancies and those pregnancies associated with perinatal death.

The effect of posture on serum human placental lactogen (HPL) levels in normal and complicated late pregnancy.

SummarySerum HPL levels were determined in the supine and upright positions at two‐hour intervals in normal and complicated late pregnancies. No significant difference could be demonstrated.

Human placental lactogen levels and intrapartum fetal distress: Meconium-stained amniotic fluid, fetal heart rate patterns, and Apgar scores

Serum human placental lactogen (HPL) levels were serially determined by a solid-phase radioimmunoassay technique. A total of 1,595 samples were obtained on 1,100 women with high-risk pregnancies. The infants were monitored during labor for signs of intrapartum distress. There was no relationship found between the HPL levels and the fetal heart rate patterns recorded during more than 400 hours of labor by continuous invasive electronic techniques. There was also no relationship between the HPL levels and the 5 minute neonatal Apgar score. There was a positive and significant correlation between the level of HPL one day before labor and the one-minute Apgar score. In addition, there were significantly more lower HPL values found in those pregnancies with meconium-stained amniotic fluid and a vertex presentation. These results suggest that HPL may be clinically useful as a placental function test but also that it cannot be the only tool used for the selection of patients for intrapartum biophysical fetal monitoring.

Hormone studies of an ovarian dysgerminoma

This investigation provides quantitative information about the hormone production of a 13-year-old girl with a dysgerminoma of the ovary. Before operation, 25,000 I.U. of human chorionic gonadotropin (HCG) per liter of urine was found, which dropped to levels of 2,000 I.U. of HCG per liter and started to increase 75 days later. The patient died because of extensive metastases 105 days after operation, when the HCG levels were at 1,280,000 I.U. of HCG per liter of urine. 17-Ketosteroids were at 24 mg. per cent before operation and dropped to normal levels afterward. At 80 days after operation, serum HCG levels were at 987.5 I.U. of HCG per milliliter of serum, and serum human placental lactogen (HPL) was at 50 ng. of HPL per milliliter of serum. Tissue of the tumor and of the metastases of the lungs was extracted and assayed for HCG and HPL. We found 111.16 I.U. of HCG and 1,693 ng. of HPL per gram of extracted tissue of the ovarian dysgerminoma. The hormone concentration in the metastatic tissue of the lungs was 3,452.92 I.U. of HCG and 270 ng. of HPL per gram of tissue. The assay of extractable material of the pituitary revealed only 0.2 I.U. of HCG in the whole organ. On grounds of these data, it is concluded that the HCG and HPL were produced by the ovarian tumor and the metastatic tissue.

Serum placental lactogen activity in patients with molar pregnancy and trophoblastic tumors—A reliable index of malignancy

Serum human placental lactogen (HPL) activity has been measured in patients with molar pregnancy and trophoblastic tumors of gestational and nongestational origin. The serum HPL activity of patients with molar pregnancy was related to the histologic grading of the tumor and gestational age and did not correlate with the metabolic activity of the trophoblastic tissue as reflected in the HCG titer. The greater the degree of malignancy, the lower the HPL level. Furthermore, malignant trophoblastic tissue appears to have similar HPL-reducing activity regardless of its origin, gestational or nongestational. This observation may form the basis for a useful tool in predicting the neoplastic potential of an hydatidiform mole. The half-life of HPL produced by molar pregnancy appears to be larger than that reported for normal pregnancy at term.

Serial estimation of human placental lactogen, estriol, and pregnanediol in pregnancy correlated with whole organ section of placenta

A technique for the sectioning of whole placentas has been developed and applied to studies made concomitantly with estimations of serum human placental lactogen (HPL), urinary estriol, and pregnanediol in normal and abnormal pregnancies. Twenty-four diabetic subjects delivered of healthy babies showed normal values. Three diabetic subjects with death in utero after 35 weeks had low estriol levels; pregnanediol and HPL were normal. In three diabetics with stillbirths, all measurements were low and there were hydropic placental changes. No abnormalities were found in 14 pre-eclamptic subjects delivered of healthy babies. In three severely toxemic patients with stillbirths or fetal distress, all estimations were low. The placentas showed infarction and fibrosis. No relationship was found between HPL and placental weight. Evidence is presented that HPL is a qualitative index of placental growth and function and urinary estriol is an index of fetal status.

SERUM PLACENTAL LACTOGEN LEVELS DURING PREGNANCY AND IN TROPHOBLASTIC DISEASE

A quantitative radioimmunoassay for human placental lactogen (HPL) in serum is described utilizing a highly purified preparation of HPL. HPL was detected in the serum of pregnant women as early as the sixth week of gestation and the levels rose steadily during the first and second trimesters, reaching a plateau during the third trimester. Serum HPL levels show little variation during the day and are not affected by induced hypoglycemia or hyperglycemia. HPL disappears promptly from the blood after delivery with a half-life in serum of approximately 30 min. Relatively small quantities of HPL were detectable in umbilical cord blood, indicating only a minor transplacental transfer of this protein. HPL was measured in the serum of 6 patients with trophoblastic tumors, and the levels were comparable to those of early pregnancy or lower.

Serum placental lactogen levels during pregnancy and in trophoblastic disease.

A quantitative radioimmunoassay for human placental lactogen (HPL) in serum is described utilizing a highly purified preparation of HPL. HPL was detected in the serum of pregnant women as early as the sixth week of gestation and the levels rose steadily during the first and second trimesters, reaching a plateau during the third trimester. Serum HPL levels show little variation during the day and are not affected by induced hypoglycemia or hyperglycemia. HPL disappears promptly from the blood after delivery with a half-life in serum of approximately 30 min. Relatively small quantities of HPL were detectable in umbilical cord blood, indicating only a minor transplacental transfer of this protein. HPL was measured in the serum of 6 patients with trophoblastic tumors, and the levels were comparable to those of early pregnancy or lower.