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At least 19 recordsLinked to original sources
PubMed2000

Maternal hydration for increasing amniotic fluid volume in oligohydramnios and normal amniotic fluid volume.

BACKGROUND: Oligohydramnios (reduced amniotic fluid) may be responsible for malpresentation problems, umbilical cord compression, concentration of meconium in the liquor, and difficult or failed external cephalic version. Simple maternal hydration has been suggested as a way of increasing amniotic fluid volume in order to reduce some of these problems. OBJECTIVES: The objective of this review was to assess the effects of maternal hydration on amniotic fluid volume and measures of pregnancy outcome. SEARCH STRATEGY: The Cochrane Pregnancy and Childbirth Group trials register and the Cochrane Controlled Trials Register were searched. Date of last search: 1 February 1999. SELECTION CRITERIA: Randomised trials comparing maternal hydration with no hydration in pregnant women with reduced or normal amniotic fluid volume. DATA COLLECTION AND ANALYSIS: Eligibility and trial quality were assessed by both reviewers. MAIN RESULTS: Two studies of 77 women were included. The women were asked to drink two litres of water before having a repeat ultrasound examination. Maternal hydration in women with and without oligohydramnios was associated with an increase in amniotic volume (weighted mean difference for women with oligohydramnios 2.01, 95% confidence interval 1.43 to 2.56; and weighted mean difference for women with normal amniotic fluid volume 4.5, 95% confidence interval 2.92 to 6.08). Intravenous hypotonic hydration in women with oligohydramnios was associated with an increase in amniotic fluid volume (weighted mean difference 2.3, 95% confidence interval 1.36 to 3.24). Isotonic intravenous hydration had no measurable effect. No clinically important outcomes were assessed in any of the trials. REVIEWER'S CONCLUSIONS: Simple maternal hydration appears to increase amniotic fluid volume and may be beneficial in the management of oligohydramnios and prevention of oligohydramnios during labour or prior to external cephalic version. Controlled trials are needed to assess the clinical benefits and possible risks of maternal hydration for specific clinical purposes.

Amniotic Fluid↗
PubMed1999

Limb deformations in oligohydramnios sequence: effects of gestational age and duration of oligohydramnios.

In order to study the pathogenesis of prenatal deformities, we reviewed maternal histories, delivery records, pathology reports, radiographs, and photographs of 90 fetuses with prenatally documented oligohydramnios at gestational ages from 14 weeks to term. The causes of oligohydramnios included premature rupture of membranes (44 cases), fetal renal insufficiency (25 cases), idiopathic (15 cases), and twin-twin transfusion (6 cases). The fetuses were grouped according to gestational age at delivery and duration of oligohydramnios. Sixty-three fetuses (70%) had documented contractures. As expected, contractures were more frequent with earlier onset and longer duration of oligohydramnios. During the 2nd trimester, the frequency of contractures in fetuses with oligohydramnios was 77% compared to 52% in the 3rd trimester (chi(2) = 5.33, 1 df, P =.02). Considering all gestational ages together, 57% of fetuses had contractures after less than 2 weeks of oligohydramnios compared to 81% of fetuses with a longer duration of oligohydramnios (chi2 = 6.23, 1 df, P <.02). The type of contracture varied with gestational age. Clubfoot was the most frequent at all ages, but hand contractures such as camptodactyly were common only in the 2nd trimester while the broad flat hand originally described in Potter sequence was found almost exclusively in the fetuses with oligohydramnios in the 3rd trimester. Of the 63 fetuses with oligohydramnios and contractures, 25 (40%) had either additional malformations or family history that could explain contractures independent of oligohydramnios.

Abruptio Placentae↗
PubMed1991

First- and early second-trimester oligohydramnios-a predictor of poor fetal outcome except in iatrogenic oligohydramnios post chorionic villus biopsy.

Whereas a well-known association exists between oligohydramnios and renal agenesis, renal dysplasia, urinary tract obstruction and intrauterine growth retardation in the second half of pregnancy, the causes and prognosis of early oligohydramnios are less known. Twelve cases of first- and early second-trimester oligohydramnios were detected out of 5000 fetal screenings for malformation detection. Two out of these 12 cases occurred in patients who had undergone chorionic villus sampling, two were associated with premature rupture of membranes, six were associated with fetal cardiac malformations and two cases were idiopathic. Whereas ten out of 12 cases ended in intrauterine fetal death, spontaneous or therapeutic abortions, in the two cases which developed after chorionic villus sampling the oligohydramnios was self-limiting and these two pregnancies ended in term deliveries of normal, healthy neonates. It may be concluded that oligohydramnios in the first half of gestation bears a poor fetal prognosis except in cases where it follows chorionic villus sampling.

Journal Article↗
PubMed2004

Premature rupture of the membranes at <26 weeks' gestation: role of amnioinfusion in the management of oligohydramnios.

OBJECTIVE: We sought to evaluate whether serial amnioinfusions for persistent oligohydramnios can affect the perinatal and long-term outcomes in extreme cases of preterm premature rupture of membranes. STUDY DESIGN: All singleton pregnancies with preterm premature rupture of membranes at <26 weeks'gestation and lasting >4 days between January 1991 and December 2001 were included. Amniotic fluid volume was assessed as the maximum cord-free pocket with serial ultrasonographic examinations. Consenting women with persistent (>4 days) oligohydramnios (amniotic fluid=2 cm) received serial transabdominal amnioinfusions to maintain an amniotic fluid pocket >2 cm. The pregnancy, neonatal, and long-term neurologic outcomes of the cases that spontaneously maintained a median amniotic fluid pocket >2 cm were compared with those of women with oligohydramnios who underwent amnioinfusion but continued to have persistent oligohydramnios and with those of women in whom oligohydramnios was alleviated. Statistical analysis included the Wilcoxon rank-sum test and the Fisher exact test with a 2-tailed P<0.05 considered significant. Stepwise logistic regression analysis with the Nagelkerke adaptation of the Cox-Snell R2 was performed to assess prenatal predictors of survival in the persistent ologohydramnios group. RESULTS: Among the 49 women included in the study, 13 (26.5%) did not have oligohydramnios, the neonatal survival rate was 92%, and normal fetal lung development and neurologic outcome were achieved in all survivors. The remaining 36 women had oligohydramnios, and all underwent serial amnioinfusions, which successfully restored a median amniotic fluid pocket >2 cm for =48 hours in 11 (30%) patients. This successful amnioinfusion group was comparable with the persistent oligohydramnios group (n=25) in gestational age at first amnioinfusion (median, 20.2 weeks; range, 16-25.6 weeks; vs median, 20.3 weeks; range, 16.5-24.2 weeks; P=.4), number of amnioinfusions (median, 3; range, 1-9; vs median, 3; range, 1-5; P=.4), and interval between amnioinfusions (median, 6 days; range, 4-14 days; vs median, 8 days; range, 6-43 days; P=.1). However, patients in the persistent oligohydramnios group had a significantly shorter interval to delivery, lower neonatal survival (20%), and higher rates of pulmonary hypoplasia (62%) and abnormal neurologic outcomes (60%) than the patients in the groups in which amnioinfusion was not necessary or was successful (all P=.01). Logistic regression analysis demonstrated that after taking into consideration successful amnioinfusion (P=0.019) and administration of steroids (P=0.022), none of the other variables, including gestational age at delivery, contributed significantly to the prediction of perinatal survival in the persistent oligohydramnios group. CONCLUSION: Pregnancies with preterm premature rupture of membranes-related oligohydramnios at <26 weeks' gestation in which serial amnioinfusions successfully alleviate oligohydramnios have a perinatal outcome that is significantly better than the outcome in those with persistent oligohydramnios and is comparable with gestations with preterm premature rupture of membranes in which oligohydramnios never develops. In the persistent oligohydramnios group, successful procedures and prenatal administration of corticosteroids are the only independent predictors of perinatal survival.

Amniotic Fluid↗
PubMed1983

Oligohydramnios: clinical associations and predictive value for intrauterine growth retardation.

Intrauterine growth retardation (IUGR) is difficult to diagnose before birth. Sonographically diagnosed oligohydramnios has been reported to be highly sensitive and reliable in detecting IUGR in carefully prescreened patients. To evaluate the clinical associations of oligohydramnios and its usefulness as a method of antenatal screening for IUGR on a large obstetric service, the consecutive ultrasound examinations of 2,453 viable singleton pregnancies with intact membranes were surveyed. The 96 (3.9%) pregnancies found to be complicated by oligohydramnios were compared with 96 with the same biparietal diameters, but with normal volumes of amniotic fluid. Mothers with oligohydramnios were younger, of lower parity, and at increased clinical risk for IUGR. Of 96 infants from oligohydramnios-complicated pregnancies, 38 (40%) were small for gestational age (SGA), compared with eight (8%) infants from pregnancies without oligohydramnios. Of 46 SGA births, 38 (83%) were preceded by sonographically diagnosed oligohydramnios (p less than 0.0001). IUGR associated with oligohydramnios tended to occur in young hypertensive gravid women, whereas non-oligohydramnios-associated IUGR tended to occur in gravid women with low prepregnancy weight. With correction for the incidences of oligohydramnios and IUGR in the unselected population, it is shown that four in 10 cases of oligohydramnios would result in SGA births (40% predictive value of an abnormal test), but that only 16% of SGA births would be preceded by sonographically diagnosed oligohydramnios. Eighty-four percent of the cases would be missed. These results suggest that, although the presence of oligohydramnios should increase the clinician's index of suspicion for IUGR, routine sonographic screening to detect oligohydramnios is not warranted.

Adolescent↗
PubMed2005

[Effects of exposure to tobacco smoke on the level of low-molecular proteins in human amniotic fluid in pregnancies complicated by oligohydramnios or premature rapture of the membranes].

The purpose of the study was to estimate the concentration of the following proteins: metallothionein, beta-2-microglobuline (BMG), interleukin 6 (II-6) in the amniotic fluid of smoking women during their pregnancy complicated by idiopathic oligohydramnios or premature rupture if the membranes (PROM). The material for the study was obtained from amniotic fluid of 30 patients, complicated by oligohydramnios, during 20-42 weeks of their pregnancy. PROM was diagnosed in 15 patients. The degree of exposure to tobacco smoke was estimated on the basis of cotinine concentration measured in the serum of patients using ELISA method (Serex). In the amniotic fluid metallothionein, BMG and 11-6 were measured with "Cd/hem assay" method using 109Cd, immunoenzyme assay IMx and ELISA method (R&D) respectively. The results marked were divided into two groups according to gestational age: group A (20-30 weeks of gestation) and group B (31-42 weeks of gestation). A higher concentration of MT, BMG and 11-6 was determined in the earlier stage of pregnancy (group A), however, the highest concentration was measured in the group of women with idiopathic oligohydramnios. A positive correlation between concentrations of proteins MT/BMG was found in both groups of women (PROM r=0.877, idiopathic oligohydramnios r=0.979); MT/II-6 (PROM r=0.844, idiopathic oligohydramnios r=-0.694); BMG/II-6 (PROM r=0.839, idiopathic oligohydramnios r=0.652). In both groups, high correlation rates were observed in MT/Cd; (PROM r=0,79, oligohydramnios r=0.89). Contrasting correlations were found between MT and concentrations of Zn and Cu. The correlation rate between MT and Cu was as follows: in PROM r=-0.80, in oligohydramnios r=0.81, whereas the correlation rates between MT and Zn were: in PROM r=0.71, in oligohydramnios r=-0.77. The determination of metallothionein, beta-2 microglobuline and II-6 concentrations in the amniotic fluid can be useful in the assessment of the placenta functions and fetal growth in the conditions of exposure to tobacco smoke. The correlation of metallotionein with copper and zinc ion concentration has confirmed a lower access of these metals to fetal ovum in the conditions of exposure to tobacco smoke xenobiotics different in PROM and idiopathic oligohydramnios cases.

Adult↗
PubMed1998

Study of 224 cases of oligohydramnios and congenital malformations in a series of 225,669 consecutive births.

OBJECTIVES: To provide data on oligohydramnios associated with congenital anomalies in 225,669 consecutive pregnancies. MATERIAL AND METHODS: The malformations in this study came from births of known outcome recorded in our registry of congenital malformations. Routine ultrasonographic examination was performed. Diagnosis of oligohydramnios was made ultrasonographically. For each case, a control was chosen. RESULTS: The prevalence of this association was 0.99 per thousand (224 cases). A case-control study allowed the examination of genetic and environmental factors for the origin of oligohydramnios associated with congenital malformations. Diagnosis of oligohydramnios associated with congenital malformations was made prenatally in 32.6% of the cases; 12.0% of the infants were stillborn. Fifty-nine percent of the cases had more than one malformation, 13.8% had a chromosomal aberration, and 27.6% had multiple malformations that do not constitute a syndrome. The more frequent malformations associated with oligohydramnios were urinary, musculoskeletal, digestive and cardiac. There was increased parental consanguinity. The frequency of oligohydramnios and congenital anomalies among first-degree relatives was 4.5% and first-degree relatives had more malformations than controls (8.0 vs. 3.1%, p < 0.05). Threatened abortions and diabetes mellitus were significantly more frequent among mothers of the children with congenital malformations associated with oligohydramnios than among the controls. CONCLUSIONS: Our study demonstrated that careful fetal examination has to be performed when oligohydramnios is diagnosed as congenital malformations are often associated with oligohydramnios. We recommend the use of fetal chromosome analysis and careful ultrasonographic examination in every pregnancy complicated by oligohydramnios.

Journal Article↗
PubMedDate not supplied

Predictive value of amniotic fluid index for oligohydramnios in patients with prolonged pregnancies.

The objective of this study was to evaluate the predictive values of the amniotic fluid index for measures of perinatal morbidity and for clinical observations consistent with oligohydramnios. We evaluated positive and negative predictive value of the amniotic fluid index for measures of perinatal morbidity and for clinical observations consistent with oligohydramnios at various cutoff values for amniotic fluid index in a cohort of 449 consecutive postdates patients who had a clinician's observation of amniotic fluid quantity and quality recorded at the time of rupture of membranes. Newborn morbidity was a rare event. Clinical observations consistent with oligohydramnios had significant positive and negative predictive values for some measures of newborn morbidity. The last amniotic fluid index performed during antepartum testing had 95% confidence intervals for relative risks for these measures of newborn morbidity that included unity and therefore were not significant. At a cutoff value of 5.0 cm, the positive predictive value of the amniotic fluid index for clinical observations consistent with oligohydramnios was 50%; the negative predictive value was 85%, with a prevalence of clinical observations consistent with oligohydramnios of 19%. The presence of fetal heart rate decelerations did not significantly improve the positive predictive value of the amniotic fluid index. Higher positive predictive values were obtained at cutoff values of 4 cm and 3 cm with minimal loss in negative predictive value. The amniotic fluid index did not possess significant predictive value for measures of newborn morbidity. Clinical observations consistent with oligohydramnios at the time of rupture of membranes did have predictive value for some of these measures and thus probably are a reflection of the actual amount of fluid present inside the uterus prior to rupture of membranes. The amniotic fluid index is only a fair predictor of clinical observations consistent with oligohydramnios. Thus, a positive test correctly predicted these observations 50% of the time, with 50% false-positive results. Undertaking delivery in the 50% of patients without clinical observations consistent with oligohydramnios may lead to a higher cesarean section rate since these patients do not require induction and are subject to the risk of a failed induction of labor. A negative test correctly predicted observations consistent with normal fluid 85% of the time, with a false-negative rate of 15%. Thus, a negative test was no guarantee that observations consistent with oligohydramnios, and thus newborn morbidity, would not subsequently appear. Frequent testing with multiple modalities and induction of labor when the Bishop score is favorable remain sensible options. Induction of labor in postdates patients with a low amniotic fluid index needs to be evaluated in a yet-to-be-performed prospective randomized control trial before a low amniotic fluid index is assumed to be the sole indicator for induction of labor. More stringent cutoff values for amniotic fluid index may be justified.

Amniocentesis↗
PubMed2002

A review of amniotic fluid dynamics and the enigma of isolated oligohydramnios.

Traditionally, oligohydramnios has been implemented as a sign of potential fetal compromise and associated with an increased incidence of adverse perinatal morbidity and mortality. Decreased amniotic fluid volume is especially of concern when it occurs in conjunction with structural fetal anomalies, fetal growth restriction, postdates pregnancies, and maternal disease. Consequently, following ultrasonographic diagnosis of oligohydramnios at term, delivery is routinely advocated even in otherwise uncomplicated pregnancies with an appropriate-for-gestational-age fetus, irrespective of the presence of reassuring fetal evaluation and the absence of maternal disease. Numerous factors complicate the ultrasonographic diagnosis of oligohydramnios. These include a lack of complete detailed understanding of the physiology of the dynamics of oligohydramnios, the transient condition at times of decreased amniotic fluid volume, generally poor performance of ultrasonography in detecting oligohydramnios, an array of different ultrasound diagnostic criteria, and varying ultrasonographic thresholds. In light of the latter and the lack of prospective randomized data, is unclear that the practice of effecting delivery for isolated oligohydramnios at term is justified. This article presents physiologic dynamics of amniotic fluid, factors that may affect amniotic fluid volume, possible pitfalls in the ultrasonographic assessment of amniotic fluid volume, and the clinical significance of oligohydramnios. In addition, the literature regarding perinatal outcome associated with oligohydramnios and current available data supporting expectant noninterventional management of cases complicated by isolated oligohydramnios at term are discussed.

Amniotic Fluid↗
PubMed1997

The effect of oligohydramnios on detection of fetal anomalies with sonography.

OBJECTIVE: The sonographic examination of fetuses is generally thought to be compromised when oligohydramnios is present because of the subjective impression of less adequate visualization of fetal anatomy. The aim of this study was to evaluate the extent to which oligohydramnios limits our ability to detect major anomalies on sonograms. MATERIALS AND METHODS: Records from the University of California, San Francisco from March 4, 1989 through January 4, 1994, were reviewed to identify all cases of premature rupture of the membranes in patients who then underwent nontargeted sonography. Sonographic results in pregnancies with oligohydramnios and without oligohydramnios (control population) were compared. Follow-up was obtained from a perinatal database, autopsy reports, and medical records. RESULTS: We found 345 patients with a history of premature rupture of the membranes (175 with oligohydramnios, 170 without oligohydramnios). Gestational age of fetuses was 16-38 weeks. Major congenital anomalies, including hydronephrosis, ventriculomegaly, intestinal atresias, hydrops, congenital diaphragmatic hernia, skeletal dysplasias, cloacal malformations, and gastroschisis, were revealed on sonography in 13 of 175 pregnancies with oligohydramnios and in 17 of the 170 pregnancies in the control group. Major anomalies missed in the oligohydramnios group included cardiac anomalies, club foot, small ventral hernia, limb reduction defect, and anal atresia. Major anomalies missed in the control group were club foot, anal atresia, and tracheoesophageal fistula. All of the major anomalies missed in both groups were of the type that are known to be difficult to diagnose before birth and that are frequently missed on sonography. CONCLUSION: Although oligohydramnios subjectively degrades image resolution, sonography still reveals important fetal anatomic landmarks. Major anomalies can be detected on sonography even when the pregnancy has less than the normal amount of amniotic fluid.

Case-Control Studies↗
PubMed1990

[An epidemiological study of oligohydramnios associated with congenital malformations].

Our registry of congenital anomalies allows us to study systematically pregnancies which ended in the birth of a malformed child. Over 8 years 105,374 births were registered. A control was selected for each malformed baby. Numerous factors are studied. One of them is oligohydramnios. During the study period 199 children carriers of at least one congenital major malformation were born after a pregnancy complicated by oligohydramnios; which represent an incidence of 1.88%. Overall 2,787 malformed children were born during the study period, 7.14% of them were born after oligohydramnios (controls 1.6%, p less than 0.001). The malformations which were more often associated with oligohydramnios involved the urinary system (15.9%), the digestive system (10.2%), the genital system (5.9%) and the limbs (5.7%). A chromosomal aberrations was present in 11 infants (5.5%). Most of the isolated malformations were not associated with oligohydramnios, whereas the pregnancies which ended with the birth of a malformed baby were often complicated by oligohydramnios. Therefore when a fetal malformation is discovered during pregnancy the obstetrician should not be satisfied with the discovery of one anomaly associated with oligohydramnios. He (she) has to look carefully for other associated fetal malformations. The weight, the length and the head circumference at birth of the children born after oligohydramnios were less than those of the controls (p less than 0.001). The length of gestation was shorter (p less than 0.01). The weight of the placenta was smaller. In this study the only maternal factors which favoured the occurrence of oligohydramnios were diabetes and epilepsy.

Birth Weight↗
PubMed1993

Fetal renal artery flow velocity waveforms in normal pregnancies and pregnancies complicated by polyhydramnios and oligohydramnios.

OBJECTIVES: To determine 1) flow velocity waveform patterns in the fetal renal artery in normal pregnancies and pregnancies complicated by polyhydramnios or oligohydramnios, and 2) fetal urine output in twin gestations complicated by polyhydramnios-oligohydramnios syndrome. METHODS: Doppler waveforms were recorded in 121 normal fetuses, ten fetuses with oligohydramnios, ten with polyhydramnios, and eight sets of diamnionic twins with polyhydramnios in one gestational sac and oligohydramnios in the second sac. In the twins, the fetal urine output was also estimated. RESULTS: The pulsatility index (PI) of the renal artery in normal fetuses decreased linearly with advancing gestation. Abnormal renal artery PIs were found in four fetuses with oligohydramnios. The values in the singleton pregnancies complicated by polyhydramnios were in the range of normality for our reference limits for gestation. The PI of the renal artery in the twins with polyhydramnios was significantly lower than that from the twins with oligohydramnios. The urine output was significantly higher in twins with polyhydramnios than in twins with oligohydramnios. CONCLUSIONS: Normal pregnancies are associated with changes in the renal artery flow velocity waveforms. In fetuses with oligohydramnios, the worst fetal outcome seems to be associated with abnormal renal artery flow velocity waveforms. In fetuses with polyhydramnios, no abnormal renal artery flow velocity waveforms were found. Changes in renal perfusion influence urine output in twin gestations complicated by polyhydramnios-oligohydramnios.

Blood Flow Velocity↗
PubMed1990

A mechanism leading to reduced lung expansion and lung hypoplasia in fetal sheep during oligohydramnios.

Our aim was to determine the mechanism whereby oligohydroamnios causes reduced fetal lung expansion and eventual lung hypoplasia. We studied 20 fetal sheep during 2 to 9 days of oligohydramnios produced by drainage of amniotic and allantoic fluids during the last third of gestation. Oligohydramnios led to a reversible reduction in lung liquid volume of 19.5% within 48 hours. During oligohydramnios tracheal pressure, relative to amniotic pressure, rose by 1.7 mm Hg (p less than 0.001); pressures also tended to rise in the fetal pleural space and abdomen, relative to amniotic pressure, and to fall in the amniotic sac. Pressure increments, relative to amniotic pressure, which normally occur in the fetal trachea, pleural cavity, and abdomen during nonlabor uterine contractions, were significantly increased by 1.9 to 2.5 mm Hg during oligohydramnios. Oligohydramnios increased flexion of the fetal thoracolumbar spine, quantified as a reduction in the ratio of spinal radius of curvature to spine length (0.76 in controls vs 0.40 after oligohydramnios, p less than 0.001). In three sets of twins, only the fetus exposed to oligohydramnios was affected. A similar degree of spinal flexion imposed on normal fetal sheep cadavers increased abdominal (1.6 mm Hg), pleural (1.5 mm Hg), and tracheal (2.0 mm Hg) pressure, and caused a significant reduction in fetal lung expansion. We conclude that oligohydramnios in fetal sheep increases spinal flexion, leading to compression of abdominal contents, upward displacement of the diaphragm, and lung compression, favoring loss of fetal lung liquid. These changes, which are accentuated during nonlabor uterine contractions and are reversible, may lead to pulmonary hypoplasia if prolonged.

Abdomen↗
PubMed2002

Renal artery Doppler investigation of the etiology of oligohydramnios in postterm pregnancy.

OBJECTIVE: To investigate the etiology of oligohydramnios in postterm pregnancy using Doppler velocimetry. METHODS: Renal and umbilical artery Doppler velocimetry were performed in women with singleton postterm (287 days' or more gestation) pregnancies. The renal and umbilical artery Doppler resistance index (RI) and end-diastolic velocity were measured. Stepwise logistic regression and the two-tailed t test were used to determine whether the Doppler indices correlated with oligohydramnios (amniotic fluid index less than 5 cm). RESULTS: We studied 147 well-dated, singleton, postterm pregnancies, of which 21 (14.3%) had oligohydramnios. For the study cohort, the mean (+/-standard deviation) gestational age at Doppler was 41.4 +/- 0.45 weeks and at delivery 41.8 +/- 0.47 weeks. Stepwise logistic regression using renal and umbilical artery Doppler indices found the renal RI to be the only significant predictor of oligohydramnios: beta = -10.4186, P <.05 (odds ratio [95% confidence interval (CI)] = 0, 0.88). The renal artery RI was significantly higher in cases with oligohydramnios (RI: mean (+/-standard error) = 0.8843 +/- 0.11 versus 0.8601 +/- 0.05, P <or= 0.05). A renal artery Doppler end-diastolic velocity below the mean for gestation significantly increased the risk of oligohydramnios: relative risk (95% CI), 1.5 (1.1, 2.0). CONCLUSION: Renal artery Doppler was more predictive of oligohydramnios than the umbilical RI. The reduced renal artery end-diastolic velocity suggests that increased arterial impedance is an important factor in the development of oligohydramnios in prolonged pregnancies.

Adult↗
PubMed1991

Transcervical chorionic villus sampling and midtrimester oligohydramnios.

To study the possible association between transcervical chorionic villus sampling and midtrimester oligohydramnios, we conducted a prospective cohort study of all women who were seen for genetic counseling in the first trimester during a 2-year period. Women who chose chorionic villus sampling were compared with women who chose traditional amniocentesis for incidence of midtrimester oligohydramnios. Of 442 women exposed to chorionic villus sampling with a normal fetal karyotype, severe oligohydramnios developed in 12 (2.7%) at 16 to 23 weeks' gestation. None of the 391 women with normal fetal karyotypes who were counseled at the same time in pregnancy but who chose amniocentesis had oligohydramnios at the time of amniocentesis (p = 0.01). A nested case-control analysis was performed within the chorionic villus sampling group to evaluate risk factors associated with midtrimester oligohydramnios. Midtrimester oligohydramnios occurring after chorionic villus sampling was associated with postprocedure bleeding and elevated maternal serum alpha-fetoprotein (p less than 0.01). There were no perinatal survivors with midtrimester oligohydramnios.

Adult↗
PubMed2004

Isolated oligohydramnios is not associated with adverse perinatal outcomes.

OBJECTIVE: To examine fetal growth and perinatal outcomes in pregnancies with isolated oligohydramnios. DESIGN: A cohort study. SETTING: Multiple clinics and hospitals. POPULATION: Low risk pregnant women. METHODS: We used data from the multicentre clinical trial of Routine Antenatal Diagnostic Imaging with UltraSound (RADIUS), in which 15,151 low risk pregnant women were randomly assigned to the ultrasound screening group or the control group. Women in the screening group underwent sonographic exams at 15-22 and 31-35 weeks of gestation. Both groups could have clinically indicated sonographic exams at any time. MAIN OUTCOME MEASURES: We used changes of fetal weight z-score to assess whether fetal growth was compromised from the diagnosis of oligohydramnios until delivery, using a repeated-measures regression. We used a combined perinatal index as an indicator of adverse perinatal outcome, which consisted of severe perinatal morbidity and mortality. RESULTS: Oligohydramnios (amniotic fluid index < or =5 cm) was diagnosed in 1.5% (113/7617) of women with ultrasound screening compared with 0.8% (57/7534) among the controls. Approximately half of the oligohydramnios cases in the screening group were isolated with no clearly associated factors (e.g. premature rupture of the fetal membranes, congenital anomalies, diabetes, hypertension, postdate and intrauterine growth restriction). Fetal weight centiles in isolated oligohydramnios cases did not change significantly from diagnosis until delivery. Pregnancies with isolated oligohydramnios had perinatal outcomes similar to pregnancies with a normal amniotic fluid index. CONCLUSION: Isolated oligohydramnios is not associated with impaired fetal growth or an increased risk of adverse perinatal outcomes.

Cohort Studies↗
PubMed1991

Fetal breathing and pressures in the trachea and amniotic sac during oligohydramnios in sheep.

Oligohydramnios commonly leads to fetal lung hypoplasia, but the mechanisms are not fully understood. Our aim was to determine, in fetal sheep, the effects of prolonged oligohydramnios on the incidence and amplitude of tracheal pressure fluctuations associated with fetal breathing movements (FBM), on tracheal flow rate during periods of FBM (VtrFBM) and periods of apnea (Vtrapnea), on tracheal pressure relative to amniotic sac pressure, and on amniotic sac pressure relative to atmospheric pressure. In five sheep, oligohydramnios was induced by draining amniotic and allantoic fluids from 107 to 135 days of gestation (411.8 +/- 24.4 ml/day), resulting in fetal lung hypoplasia. In five control sheep, amniotic fluid volume was 732.3 +/- 94.4 ml. Oligohydramnios increased the incidence of FBM by 14% at 120 and 125 days and the amplitude of FBM by 30-34% at 120-130 days compared with controls. From 120 days onward, VtrFBM was 35-55% lower in experimental fetuses than in controls. Influx of lung liquid during FBM was 87% lower in experimental fetuses than in controls. Vtrapnea, tracheal pressure, and amniotic sac pressure were not significantly altered by oligohydramnios. Our tracheal flow rate data suggest that transient changes in lung liquid volume during periods of FBM and periods of apnea were diminished by oligohydramnios. We conclude that the primary factor in the etiology of oligohydramnios-induced lung hypoplasia is not an inhibition of FBM (as measured by tracheal pressure fluctuations) or a reduction in amniotic fluid pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Amnion↗
PubMed1992

Effects of acute oligohydramnios on respiratory system of fetal sheep.

Prolonged oligohydramnios, or a lack of amniotic fluid, is associated with pulmonary hypoplasia and subsequent perinatal morbidity, but it is unclear whether short-term or acute oligohydramnios has any effect on the fetal respiratory system. To investigate the acute effects of removal of amniotic fluid, we studied nine chronically catheterized fetal sheep at 122-127 days gestation. During a control period, we measured the volume of fluid in the fetal potential airways and air spaces (VL), production rate of that fluid, incidence and amplitude of fetal breathing movements, tracheal pressures, and fetal plasma concentrations of cortisol, epinephrine, and norepinephrine. We then drained the amniotic fluid for a short period of time [24-48 h, 30.0 +/- 4.0 (SE) h] and repeated the above measurements. The volume of fluid drained for the initial studies was 1,004 +/- 236 ml. Acute oligohydramnios decreased VL from 35.4 +/- 2.9 ml/kg during control to 22.0 +/- 1.6 after oligohydramnios (P less than 0.004). Acute oligohydramnios did not affect the fetal lung fluid production rate, fetal breathing movements, or any of the other measured variables. Seven repeat studies were performed in six of the fetuses after reaccumulation of the amniotic fluid at 130-138 days, and in four of these studies the lung volume also decreased, although the overall mean for the repeat studies was not significantly different (27.0 +/- 5.2 ml/kg for control vs. 25.5 +/- 5.5 ml/kg for oligohydramnios). Again, none of the other measured variables were altered by oligohydramnios in the repeat studies.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗