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PubMedDate not supplied

Impact of collaborative management and early admission in labor on method of delivery.

OBJECTIVE: This study compared the effects of early admission in labor and perinatal care provider on delivery method. Higher spontaneous vaginal delivery rates for certified nurse midwives as compared with physicians have been reported in observational studies and randomized clinical trials. Certified nurse midwives, with their more expectant approach to labor management, would be expected to admit women later in labor than obstetricians. METHODS: Prospective cohort study of 2,196 low-risk pregnancies, with singleton, vertex infants admitted in spontaneous labor. Independent and joint effects of perinatal care provider and cervical dilation at admission on delivery method were evaluated. Confounding was addressed using restriction and multiple regression. RESULTS: Fewer (23.4%) women in collaborative care were admitted in early labor (< 4 cm cervical dilation) than women managed by obstetricians (95% CI = -27.6 to -19.2). Obstetrician care had 9% to 30% fewer spontaneous vaginal deliveries. Women admitted early in labor also had 6% to 34% fewer spontaneous vaginal deliveries. Evaluation of joint effects suggested that interaction between obstetrician provider and earlier admission increased the risk of operative delivery. CONCLUSION: Later admission in labor (at 4 cm or greater cervical dilation) and management of perinatal care by certified nurse midwives in collaboration with obstetricians increased the rate of spontaneous vaginal delivery in low-risk women.

Adult↗
PubMed1977

Initiation of human parturition. VI. Identification and quantification of progesterone metabolites produced by the components of human fetal membranes.

The fetal membranes play a central role in the initiation of human parturition, a role that may be subserved in part by quantitative changes in progesterone metabolism. In order to identify and to quantify the metabolites of progesterone produced by the components of the human fetal membranes, amnion and chorion laeve tissues and homogenates were incubated with [3H]progesterone in the presence of added NADPH. The radioactive metabolites, 20alpha-hydroxy-4-pregnen-3-one, 5alpha-pregnane-3,20-dione and 3beta-hydroxy-5alpha-pregnan-20-one, were isolated and identified by derivative formation, a combination of chromatographic techniques, and by crystallization to constant specific activity after addition of authentic standards. A simplified technique of metabolite quantification was developed that involves one thin layer chromatographic procedure and liquid scintillation assay of radioactivity. The accuracy of this method was established by comparison with data obtained using classical techniques. This study demonstrates the presence of human fetal membranes 5alpha-reductase, 20alpha-hydroxysteroid oxidoreductase, and 3beta-hydroxy-steroid oxidoreductase, and a qualitative difference between amnion and chorion laeve.

20-alpha-Dihydroprogesterone↗
PubMed1998

Corticotropin-releasing hormone receptor subtype 1 is significantly up-regulated at the time of labor in the human myometrium.

Circulating concentrations of CRH rise late in human pregnancy, reaching a peak at labor. The presence of functional CRH receptors, CRH-R1 and CRH-R2, in the human myometrium suggests that CRH may modulate uterine activity. We hypothesized that the number of CRH receptors would be higher in myometrium than fetal membranes (FM) and would change during labor. Myometrial samples were collected from the lower segment (LS) in nonpregnant, preterm (32 +/- 2 weeks), and term (39 +/- 1.6 weeks) pregnant patients before and at labor. Fundus and LS samples were also collected from nonpregnant, pregnant, laboring, and postpartum women. FM were collected at term and at labor. We identified CRH receptors in myometrium and FM by semiquantitative RT-PCR and immunohistochemistry. CRH-R1 messenger ribonucleic acid (mRNA) in the LS was decreased in pregnancy and increased significantly in both preterm and term labor (P < 0.05), but remained unchanged in the fundus. CRH-R2 mRNA was present in 28% of LS myometrium with no change at labor. CRH-R1 and CRH-R2 protein was localized to myometrial smooth muscle in nonpregnant and laboring patients, with lower levels at term. CRH-R1 mRNA was present in chorion and decidua, but CRH-R2 was undetectable in these tissues. We conclude that CRH-R1 is expressed preferentially in myometrium and FM. Changes in CRH receptors during labor are consistent with CRH mediating effects on myometrial activity.

Adult↗
PubMed1996

Controlled comparison of induction versus expectant care for prelabor rupture of the membranes at term.

This randomized clinical trial compared oxytocin induction of labor with expectant care for 48 hours after prelabor rupture of the membranes at term. Women at term with prelabor rupture of the membranes for at least 8 hours were assigned at random to induction with oxytocin or to expectant management for 48 hours followed by induction if necessary. Of 168 eligible women, 123 (73%) agreed to participate. More women in the induction group (23%) than in the expectant group (10%) had operative delivery, either cesarean section or instrumental vaginal delivery. In the induction group 41% received analgesia versus 24% in the expectant group (p < 0.005). There was no difference in the rate of maternal and neonatal infection between groups and sepsis was not observed. The active policy of oxytocin induction exposed the mother to a higher risk of operative delivery and a less comfortable labor than the 48 hours expectant care option.

Analgesia, Obstetrical↗
PubMed1996

The role of fetal myoglobin in the initiation of human parturition.

The aim of the present investigation is to study the effect of amniotic fluid myoglobin on prostaglandin synthesis by the fetal membranes. The paper presents results of radioimmunologic studies of myoglobin levels in various biological fluids during pregnancy: amniotic fluid, maternal serum samples obtained from an antecubital vein and the cervix, and neonatal urine. Amniotic fluid myoglobin levels were found to be significantly higher at term. Our results suggest that amniotic fluid myoglobin is likely to be derived from the fetus and excreted into amniotic fluid through fetal urine. Incubation of the fetal membrane with amniotic fluid, neonatal urine, and commercially available myoglobin enhanced phospholipase A2 activity, as well as arachidonic acid and prostaglandin F2 alpha production was compared to incubation with normal saline. The addition of anti-myoglobin antibodies to incubation media was found to block these effects. The results of our study show that myoglobin activates prostaglandin synthesis by the fetal membranes and stimulates the onset of labor.

Amniotic Fluid↗
PubMed1994

Term prediction in routine ultrasound practice.

STUDY OBJECTIVE: Evaluation of the precision of routine ultrasound term prediction. DESIGN: Population based follow-up without intervention. SETTING: Ultrasound screening in routine clinical practice. MATERIAL: 1650 women residing in one Norwegian county giving birth during a 12-month period. All pregnancies were singleton with spontaneous onset of labor, all records contained a term predicted with routine ultrasound in the second trimester. OUTCOME MEASURE: Difference between actual and predicted day of delivery, and difference between ultrasound predicted term and term calculated from last menstrual period. MAIN RESULTS: More women delivered within two weeks of ultrasound term than two weeks of term calculated from the last menstrual period (87.5% and 79.3%, p < 0.001). Deliveries were significantly closer to the ultrasound predicted term than the term calculated from the last menstrual period, with the exception of deliveries in the 39th week after LMP where no significant difference was found between ultrasound term and LMP-term. No difference was found in the mean performance of 14 different ultrasound operators. CONCLUSIONS: In a population representative of deliveries in one county, routine ultrasound term prediction performed in three medium sized hospitals more accurately predicted day of delivery than term calculated from the date of last menstrual period.

Analysis of Variance↗
PubMed1995

Perinatal outcome after in vitro fertilisation.

A prospective series of 90 consecutive pregnancies (70 singleton, 16 twin and 4 triplet pregnancies) resulting in births of 114 infants after in vitro fertilisation (IVF) at Rigshospitalet were compared to a control group of pregnancies and deliveries in 70 non-IVF infertility patients with singleton pregnancies and 20 women with normal fertility with twin (n = 16) or triplet (n = 4) pregnancies. No differences in the incidence of third trimester pregnancy complications, abnormal fetal karyotypes or malformations were found. The number of women with spontaneous onset of labor and the gestational age at delivery were similar in the IVF and control groups. In singleton deliveries, the birth weight was lower (p < 0.025) in the IVF group (median 3145 g, range 890-4300 g) than in the control group (3399 g, 2592-4850 g), whereas in multiple gestation similar birth weights were found in the IVF and control groups. We conclude that the birth weight in singleton deliveries after IVF is lower than the birth weight in infertility patients treated differently. The cause of this difference remains obscure.

Adult↗
PubMed1993

Endothelin-1 receptors on the human placenta and fetal membranes: evidence for different binding properties in pre-eclamptic pregnancies.

Densities and affinities of tissue protein receptor sites for endothelin-1 in placental and fetal membranes of six preeclamptic and 16 normotensive women in the 36-41st week of gestation were determined by the use of a binding assay with [125I]endothelin-1. The mean maximal density of receptor sites (Bmax) was significantly higher in the placentas of the pre-eclamptic than of the normotensive women (905 +/- 107 vs. 539 +/- 140 fmol/mg protein, p < 0.0001). No differences were found between the two groups with respect to the mean affinity (Kd) of placental receptors, or the mean Bmax and the mean Kd of fetal chorionic samples. In the normotensive group, there were no differences in mean placental Bmax values or in mean Kd values between women who went into spontaneous labor (whether delivered vaginally or abdominally) and those who were electively operated on prior to labor onset. No binding sites were detected in the fetal amniotic membranes of any of the women. Our results suggest that an increase in the maximal density of receptor sites to endothelin-1 in the placenta may play a role in the pathophysiology of pre-eclampsia by contributing to the placental insufficiency that characterizes this disorder.

Endothelins↗
PubMed1976

[Course observation after intra-amniotic administration of lecithin in premature cesarean section].

A report of a 36 year old patient is given who was hospitalized because of an erythroblastosis. An indicated sectio caesarea resulted in an intraamnial application of lecithine for preventing a respiratory distress syndrome. It can be concluded by the measured lecithin-concentration that a high phospholipid-level in the amniotic fluid leads to an increased resorption by the fetus. Postpartal investigations showed a completely normal lung function in the newborne.

Amnion↗
PubMed1976

[Induction of labor with prostaglandin F 2 alpha in diabetes mellitus].

At 15 diabetic patients of the 36. to 40. week of pregnancy labour was induced by Prostaglandin F2alpha-infusion. The sure effect on uterus activity is characterized by prompt dilatation of the cervix. A disadvangeous influence could not be observed on blood circulation and digestive system both of the diabetic patient and fetus respectively newborn.

Acid-Base Equilibrium↗
PubMed1976

Clinical application of prostaglandins in obstetrics and gynecology.

After a short discussion on the development of the prostaglandins, the application especially of F2 alpha and E2 in the field of obstetrics and gynecology were debated. Predominantly clinical data on the induction of abortion in the second trimester of pregnancy as well as the induction of labour at term are reviewed. The individual methods of application are discussed. Additionally, possible future areas of use, such as the regulation of menstruation and new prostaglandin derivates are discussed.

Abortion, Induced↗