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Biomedical subjects

A H Moawad

Publications and source records attributed to A H Moawad.

At least 37 records · Page 2Linked to original sources
PubMed1997

The Preterm Prediction Study: association of cesarean delivery with increases in maternal weight and body mass index.

OBJECTIVE: Our purpose was to evaluate whether maternal weight and body mass index measured either before or during pregnancy are associated with an increased risk of cesarean delivery. STUDY DESIGN: Maternal weight and height were prospectively collected on 2929 women in the National Institutes of Health Maternal-Fetal Medicine Units Network Preterm Prediction Study. Prepregnancy and 27- to 31-week maternal weight and height were used to calculate the body mass index, and its contribution to the risk of cesarean delivery was determined. Women with prenatally diagnosed congenital anomalies (n = 89) and pregestational diabetes (n = 31) were excluded from analysis. RESULTS: Univariate analysis of risk factors for cesarean delivery in the 2809 eligible women revealed a decreased risk of cesarean delivery with maternal age < 18 years and multiparity; increased risk of cesarean delivery was noted with maternal age > 35 years and a male fetus. Increases in either prepregnancy or 27- to 31-week maternal weight (5-pound units) or body mass index (1.0 kg/m2 units) were significantly associated with an increased odds of cesarean delivery (p = 0.0001). Each unit increase in prepregnancy or 27- to 31-week body mass index resulted in a parallel increase in the odds of cesarean delivery of 7.0% and 7.8%, respectively. Multivariable stepwise logistic regression analysis confirmed the association of male fetus, age, nulliparity, and body mass index as significant variables contributing to cesarean delivery risk. CONCLUSIONS: The risk of cesarean delivery is associated with incremental changes in maternal weight and body mass index before and during pregnancy after adjustment for potential confounding factors. Prepregnancy counseling about optimizing maternal weight and monitoring weight gain during pregnancy to decrease the risk of cesarean delivery are supported by this study.

Adolescent↗
PubMed1997

Obstetric determinants of neonatal survival: influence of willingness to perform cesarean delivery on survival of extremely low-birth-weight infants. National Institute of Child Health and Human Development Network of Maternal-Fetal Medicine Units.

OBJECTIVE: Our purpose was to evaluate the relationship between the approach to obstetric management and survival of extremely low-birth-weight infants. STUDY DESIGN: In this prospective observational study we evaluated 713 singleton births of infants weighing < or = 1000 gm during 1 year at the 11 tertiary perinatal care centers of the National Institutes of Child Health and Human Development network of maternal-fetal medicine units. Major anomalies, extramural delivery, antepartum stillbirth, induced abortion, and gestational age < 21 weeks were excluded. The obstetrician's opinion of viability and willingness to perform cesarean delivery in the event of fetal distress were ascertained from the medical record or interview when documentation was unclear. Grade 3 and 4 intraventricular hemorrhage, grade 3 and 4 retinopathy of prematurity, necrotizing enterocolitis requiring surgery, oxygen dependence at discharge or 120 days, and seizures were considered serious morbidity. Survival without serious morbidity was considered intact survival. Logistic regression was used to evaluate the influence of the approach to obstetric management, adjusted for birth weight, growth, gender, presentation, and ethnicity. RESULTS: Willingness to perform cesarean delivery was associated with increased likelihood of both survival (adjusted odds ratio 3.7, 95% confidence interval 2.3 to 6.0) and intact survival (adjusted odds ratio 1.8, 95% confidence interval 1.0 to 3.3). Willingness to intervene for fetal indications appeared to virtually eliminate intrapartum stillbirth and to reduce neonatal mortality. Below 800 gm or 26 weeks, however, willingness to perform cesarean delivery was linked to an increased chance of survival with serious morbidity. Although obstetricians were willing to intervene for fetal indications in most cases by 24 weeks, willingness to perform cesarean delivery was associated with twice the risk for serious morbidity at that gestational age. CONCLUSIONS: The approach to obstetric management significantly influences the outcome of extremely low-birth-weight infants. Above 800 gm or 26 weeks the obstetrician should usually be willing to perform cesarean delivery for fetal indications. Between 22 and 25 weeks willingness to intervene results in greater likelihood of both intact survival and survival with serious morbidity. In these cases patients and physicians should be aware of the impact of the approach to obstetric management and consider the likelihood of serious morbidity and mortality when formulating plans for delivery.

Cesarean Section↗
PubMed1997

The preterm prediction study: patterns of cervicovaginal fetal fibronectin as predictors of spontaneous preterm delivery. National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network.

OBJECTIVE: Our purpose was to determine how various temporal patterns of fetal fibronectin positivity from 24 to 30 weeks predict subsequent fetal fibronectin test results and spontaneous preterm delivery. STUDY DESIGN: A total of 2929 women had vaginal and cervical fetal fibronectin tests obtained at least once at 24, 26, 28, or 30 weeks, and 1870 women had tests performed at all four gestational ages. Fetal fibronectin values > or = 50 ng/ml were considered positive. Various patterns of positive and negative tests were evaluated for prediction of (1) whether the next fetal fibronectin test would be positive or negative and (2) the percent of women with a spontaneous preterm delivery > or = 4 weeks after the last fetal fibronectin test at < 30, < 32, < 35, and < 37 weeks' gestational age. RESULTS: Women with previous negative test results had only a 3% chance of a subsequent positive test result; however, if the last test result was positive, 29% of the next tests were positive. Of the 1870 women with tests at 24, 26, 28, and 30 weeks, 89% had all negative results, 8.4% had one positive result, 1.8% had two positive results, and 0.8% had three or four positive results. The higher the percent of positive tests at 24 to 26 weeks, at 28 to 30 weeks, or at 24 to 30 weeks, the greater the risk of subsequent spontaneous preterm birth. As an example, the risk of spontaneous preterm birth at < 30 weeks for women with two negative fetal fibronectin test results at 24 and 26 weeks was 0.3% versus 16% for women with two positive results. CONCLUSION: The presence of a positive cervical or vaginal fetal fibronectin test result predicts subsequent positive fetal fibronectin positivity and subsequent spontaneous preterm birth. The greater the percent of positive results, the higher is the risk of spontaneous preterm birth. After a positive test result, two negative results are required before the risk of spontaneous preterm birth returns to baseline.

Cervix Uteri↗
PubMed1997

Postcesarean analgesia with both epidural morphine and intravenous patient-controlled analgesia: neurobehavioral outcomes among nursing neonates.

UNLABELLED: Among nursing parturients after cesarean delivery, intravenous patient-controlled analgesia (PCA) with meperidine is associated with significantly more neonatal neurobehavioral depression than PCA with morphine. A single dose of epidural morphine (4 mg) decreases postcesarean opioid analgesic requirements and may reduce or prevent neonatal neurobehavioral depression associated with PCA meperidine. Prospectively, 102 term parturients underwent cesarean delivery with epidural anesthesia, 2% lidocaine and epinephrine 1:200,000. After umbilical cord clamping, each patient received epidural morphine 4 mg and was randomly allocated to receive either PCA meperidine or PCA morphine. Initial neonatal characteristics, included gestational age, Apgar scores, weight, and umbilical cord gas partial pressures. Brazelton Neonatal Behavioral Assessment Scale (NBAS) examinations were performed on each of the first 4 days of life. Nursing infants (n = 47) were grouped according to maternal PCA opioid in breast milk (meperidine [n = 24] or morphine [n = 23]); bottle-fed infants (n = 56) served as the control group. The three infant groups were equivalent with respect to initial characteristics and NBAS scores on the first 2 days of life. On the third day of life, infants in the morphine group were significantly more alert and oriented to animate human cues compared with infants in the meperidine or control group. On the fourth day of life, infants in the morphine group remained significantly more alert and oriented to animate human auditory cues than infants in the meperidine group. Average PCA opioid consumption through 48 h postpartum was equivalent (0.54 mg/kg morphine and 4.7 mg/kg meperidine); however, even with these small doses, meperidine was associated with significantly poorer neonatal alertness and orientation than morphine. Morphine is the PCA opioid of choice for postcesarean analgesia among nursing parturients. IMPLICATIONS: Among nursing parturients after cesarean delivery, intravenous patient-controlled analgesia with meperidine is associated with more neonatal neurobehavioral depression than patient-controlled analgesia with morphine. In this study, we found that nursing infants exposed to morphine were more alert and oriented to animate human cues than those exposed to meperidine.

Adult↗
PubMed1996

The preterm prediction study: fetal fibronectin, bacterial vaginosis, and peripartum infection. NICHD Maternal Fetal Medicine Units Network.

OBJECTIVE: To determine the relation between vaginal and upper genital tract infection and cervical-vaginal fetal fibronectin levels. METHODS: We screened 2899 women at ten centers every 2 weeks from 23-24 to 30 weeks' gestation for cervical and vaginal fetal fibronectin. A positive test was defined as a level of at least 50 ng/mL. The relation between a positive test and bacterial vaginosis at 23-24 weeks and clinical or histologic chorioamnionitis at delivery plus neonatal sepsis was determined. RESULTS: Fetal fibronectin was present in 4.0% of cervical and/or vaginal samples at 23-24 weeks and was nearly twice as common in women with bacterial vaginosis. Adjusting for the presence of bacterial vaginosis, race, and parity, women positive for fetal fibronectin were much more likely to have clinical chorioamnionitis (mean +/- standard deviation gestational age 30.6 +/- 4.1 weeks), with an odds ratio of 16.4 and 95% confidence interval of 7.1-37.8, and neonatal sepsis (6.3 and 2.0-20.0, respectively), than those who were fetal fibronectin-negative. A positive cervical fetal fibronectin test was a better predictor of clinical chorioamnionitis and neonatal sepsis than was a vaginal test or a combination of vaginal and cervical tests. Among 40 women who delivered before 32 weeks and had placental histology available for evaluation, ten had a positive cervical and/or vaginal fetal fibronectin test before delivery; all ten had histologic evidence of chorioamnionitis, compared with only 13 of 30 women (43%) who were fetal fibronectin-negative (P = .02). CONCLUSION: Women with bacterial vaginosis were more likely to have a positive fetal fibronectin test than uninfected women. Women with a positive fetal fibronectin test who delivered before 32 weeks' gestation all had evidence of histologic chorioamnionitis. Women positive for fetal fibronectin also had a 16-fold increase in clinical chorioamnionitis and a sixfold increase in neonatal sepsis. There is strong evidence that upper genital tract infection and cervical and/or vaginal fetal fibronectin are closely linked.

Adult↗
PubMed1996

The preterm prediction study: a clinical risk assessment system.

OBJECTIVE: Our aims were to develop a risk assessment system for the prediction of spontaneous preterm delivery using clinical information available at 23 to 24 weeks' gestation and to determine the predictive value of such a system. STUDY DESIGN: A total of 2929 women were evaluated between 23 and 24 weeks' gestation at 10 centers. Demographic factors, socioeconomic status, home and work environment, drug and alcohol use, and medical history were evaluated. Information regarding symptoms, cultures, and treatments in the current pregnancy were ascertained. Anthropomorphic and cervical examinations were performed. Univariate analysis and multivariate logistic regression were performed in a random selection, constituting 85% of the study population. The derived risk assessment system was applied to the remaining 15% of the population to evaluate its validity. RESULTS: A total of 10.4% of women were delivered of preterm infants. The multivariate models for spontaneous preterm delivery were highly associated with spontaneous preterm delivery (p < 0.0001). A low body mass index (<19.8) and increasing Bishop scores were significantly associated with spontaneous preterm delivery in nulliparous and multiparous women. Black race, poor social environment, and work during pregnancy were associated with increased risk for nulliparous women. Prior obstetric outcome overshadowed socioeconomic risk factors in multiparous women with a twofold increase in the odds of spontaneous preterm delivery for each prior spontaneous preterm delivery. Current pregnancy symptoms, including vaginal bleeding, symptomatic contractions within 2 weeks, and acute or chronic lung disease were variably associated with spontaneous preterm delivery in nulliparous and multiparous women. When the system was applied to the remainder of the population, women defined to be at high risk for spontaneous preterm delivery (> or = 20% risk) carried a 3.8-fold (nulliparous women) and 3.3-fold (multiparous women) higher risk of spontaneous preterm delivery than those predicted to be at low risk. However, the risk assessment system identified a minority of women who had spontaneous preterm deliveries. The sensitivities were 24.2% and 18.2% and positive predictive values were 28.6% and 33.3%, respectively, for nulliparous and multiparous women. CONCLUSIONS: Although it is possible to develop a graded risk assessment system that includes factors that are highly associated with spontaneous preterm delivery in nulliparous and multiparous women, such a system does not identify most women who subsequently have a spontaneous preterm delivery. This system has investigational value as the basis for evaluating new technologies designed to identify at-risk subpopulations.

Black People↗
PubMed1996

The preterm prediction study: risk factors in twin gestations. National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network.

OBJECTIVE: Our purpose was to determine the association between the presence of bacterial vaginosis, fetal fibronectin, and a short cervix and the risk of spontaneous preterm birth of twins. STUDY DESIGN: We prospectively screened 147 women with twins at 24 and 28 weeks' gestation for more than 50 potential risk factors for spontaneous preterm birth. We also measured cervical length with ultrasound scans and tested for the presence of bacterial vaginosis. Fetal fibronectin level was evaluated every 2 weeks from 24 to 30 weeks' gestation. Outcomes included spontaneous preterm birth at < 32 weeks, < 35 weeks, and < 37 weeks. RESULTS: Among twin as compared with singleton pregnancies, a cervical length < or = 25 mm was more common at both 24 and 28 weeks, a statistically significant difference. There were no significant differences in most other risk factors. Of the factors evaluated by means of univariate analysis at 24 weeks, only a short cervix (< or = 25 mm) was consistently associated with spontaneous preterm birth. The odds ratio and 95% confidence interval for spontaneous preterm birth at < 32 weeks, < 35 weeks, and < 37 weeks were 6.9 (2.0 to 24.2), 3.2 (1.3 to 7.9), and 2.8 (1.1 to 7.7). At 28 weeks, a cervical length < or = 25 mm was not a strong predictor of spontaneous preterm birth. At both 28 weeks (odds ratio, 9.4; confidence interval, 1.0 to 67.7) and 30 weeks (odds ratio 46.1; confidence interval, 4.2 to 1381), a positive fetal fibronectin result was significantly associated with spontaneous preterm birth at < 32 weeks. Bacterial vaginosis at 24 or 28 weeks was not associated with spontaneous preterm birth of twins. Multivariate analysis confirmed the association between cervical length < or = 25 mm at the 24-week visit and spontaneous preterm birth and also confirmed that at 24 weeks the other risk factors were less consistently and often not statistically significantly associated with spontaneous preterm birth. Of the risk factors evaluated at 28 weeks, only a positive fetal fibronectin was associated with a significantly increased risk for spontaneous preterm birth. CONCLUSIONS: Most known risk factors for spontaneous preterm birth were not significantly associated with spontaneous preterm birth of twins. At 24 weeks, cervical length < or = 25 mm was the best predictor of spontaneous preterm birth at < 32 weeks, < 35 weeks, and < 37 weeks. Of the risk factors evaluated at 28 weeks, fetal fibronectin was the only statistically significant predictor of spontaneous preterm birth at < 32 weeks.

Adolescent↗
PubMed1994

Reducing the frequency of low birth weight in the United States.

We sought to determine by what amount the frequency of low birth weight (LBW) could be reduced by eliminating its known, preventable risk factors. Based on the prevalence of risk factors such as cigarette smoking (exposure) in a population, and the degree of association (relative risk) between the risk factors and the outcome of LBW, we estimated the percentage of LBW in the United States attributable to the risk factors (population-attributable risk percentage). We found the following associations with known preventable LBW: Cigarette smoking accounts for 9.6%; alcohol consumption during pregnancy, 2.3%; low pre-pregnancy weight (less than 54 kg), 6.3%; urinary tract infections, 1.3%; Chlamydia trachomatis genital infections, 4.8%; and narcotics addiction, 3.8%. Because these risk factors are not mutually exclusive, eg, narcotics addicts may be addicted to both narcotics and cigarettes, the maximum preventable population-attributable risk percentage for LBW is less than the sum of the individual risk factors, which is 28.1% (9.6% [cigarette smoking] + 2.3% [alcohol consumption] + 6.3% [low pre-pregnancy weight] + 1.3% [urinary tract infection] + 4.8% [Chlamydia] + 3.8% [narcotics addiction] = 28.1%). Given the current state of knowledge about preventable risk factors, LBW can be reduced--in an idealized model--from only 6.9 to 5.0% of all births. In a more realistic model, we estimate that LBW can be reduced from only 6.9 to 6.3% of all births. Therefore, a national effort is indicated to identify unknown preventable causes of LBW.

Female↗
PubMed1993

Opioid antagonist adjuncts to epidural morphine for postcesarean analgesia: maternal outcomes.

This prospective, randomized, controlled investigation compared the effects of three prophylactic mu-opioid antagonists, epidural butorphanol (BU) 3 mg, epidural nalbuphine (NB) 10 mg, and oral naltrexone (NX) 6 mg, on postcesarean epidural morphine analgesia. After randomization, 102 term parturients underwent cesarean delivery with epidural anesthesia, 2% lidocaine and epinephrine 1:200,000. When the umbilical cord was clamped, each patient received one epidural solution (containing morphine 4 mg plus either saline or treatment drug), and one oral capsule (containing either placebo or treatment drug) in a double-blind manner. Maternal outcomes included pain and satisfaction [assessed with 100-mm visual analog scales (VAS)], and the incidence and severity of respiratory depression, somnolence, pruritus, nausea, and emesis. Through the first 12 h postpartum, the BU group achieved significantly greater analgesia than the morphine sulfate (control) (MS), NB, and NX groups, a significantly lower incidence of severe pruritus than the MS group, and significantly greater satisfaction than MS and NX groups. Epidural morphine and BU promoted better analgesia and satisfaction than any previously documented postcesarean regimen.

Adult↗
PubMed1991

The effect of filtration of amniotic fluid on the growth of Chlamydia trachomatis and Escherichia coli.

There is increasing concern about Chlamydia trachomatis infection during pregnancy, because of reports of increased maternal, fetal, and neonatal risks. Amniotic fluid is known to possess antibacterial activity and has recently been shown to inhibit formation of chlamydial inclusions in McCoy cell culture. To further characterize the anti-chlamydial factor, we investigated the effect of filtering the fluid (0.45 microns pores) prior to incubation. Amniotic fluid was obtained from 12 women at term gestation, either by amniocentesis, or at cesarean section, Chlamydial inclusion formation was studied in McCoy cell cultures, and Escherichia coli growth was studied by a plate-count method. Filtered amniotic fluid had significantly less inhibitory activity against chlamydial inclusion formation than nonfiltered fluid did. Both filtered and nonfiltered amniotic fluid were equally effective in inhibiting E. coli colony growth. These data suggest that the chlamydial inhibitor in amniotic fluid does not pass through 0.45 microns pores and is larger than the bacterial inhibitor that was reported to be a peptide of low molecular weight.

Amniotic Fluid↗
PubMed1991

Cesarean: changing the trends.

A rising cesarean birth rate, both nationally and at our institution, led us to attempt to reverse the trend. Vaginal birth after cesarean (VBAC) was introduced as an alternative to repeat cesarean in 1982. The impact of VBAC on the cesarean rate for our institution was assessed from 1982-1988. Over the period studied, the rate of repeat cesarean rose from 5.0% in 1982 to 6.9% in 1985, then steadily fell to 5.3% in 1988. During this same period, the primary cesarean rate rose from 7.5% in 1982 to 11.9% in 1986, then declined to 10.6% in 1988. Changes in the rate for all cesareans paralleled those for primary procedures: 12.5% in 1982, 17.6% in 1986, and 15.9% in 1988. In patients with a history of previous cesarean, the relative risk of repeat cesarean dropped from 10.2 (95% confidence interval 8.8-11.8) in 1982 to 5.2 (95% confidence interval 4.5-6.0) in 1988. In the face of a rising rate of primary cesarean births, the introduction of VBAC has helped to stabilize the overall cesarean rate at our institution.

Adult↗
PubMed1991

Use of the drop volume of amniotic fluid in predicting fetal lung maturity. Clinical experience.

Respiratory distress syndrome (RDS), resulting from inadequate amounts of alveolar surfactant, is a leading cause of neonatal mortality. This study analyzed the drop volume for predicting the risk of neonatal RDS by evaluating the surface tension of amniotic fluid. The drop-volume method quantifies the surface tension of amniotic fluid using the fact that the volume of a falling drop of liquid is proportional to the quantity of surface-active substances (surfactant) in the solution. Distilled water is used as a reference solution. The test is simple to perform and requires only two minutes and 2 mL of amniotic fluid. Amniotic fluid was obtained by amniocentesis from 120 pregnancies, ranging from 24 to 42 weeks of gestation, within four days of delivery. Specimens contaminated with meconium or hemolyzed blood or from patients with clinical chorioamnionitis were not used. The lecithin:sphingomyelin ratio and phosphatidylglycerol tests were also determined for 54 of the study cases. A mature drop-volume test result was associated with a healthy infant with no RDS 95% of the time (negative predictive value). Fifty-two percent of the healthy infants in the study were predicted by an arbitrary unit of time (S) value of less than or equal to 85.0 (specificity). Thirteen of the 16 infants who developed RDS (81%) were predicted by an S value of greater than or equal to 85.1 (sensitivity). Of those infants with an S value of greater than or equal to 85.1, 21% developed RDS (positive predictive value).

Adult↗
PubMed1990

A model for the prospective analysis of perinatal deaths in a perinatal network.

This prospective study assesses factors that contribute to perinatal mortality. The study population includes the 1362 perinatal deaths that occurred among 85,402 live births between 1983 and 1987 at hospitals of the University of Chicago Perinatal Network. After peer review of demographic, clinical, and pathologic data, each perinatal death was classified in one of the following categories: (1) the result of congenital malformation incompatible with life, (2) unavoidable, (3) potentially avoidable by patient, by health provider, or by both, or (4) of undetermined responsibility. Of 1362 deaths, 12.3% involved congenital malformations incompatible with life, 56.9% were classified as unavoidable, 28.1% were judged potentially avoidable, and 2.7% due to undetermined causes. Of potentially avoidable deaths, 36% were due to patient factors (primarily noncompliance), 59% to health provider factors, and 15% to combined patient and provider factors. There was a significant reduction in the potentially avoidable cases during the study period. The maximum attainable reduction in perinatal mortality under optimal conditions is calculated. Intervention plans to achieve this goal are discussed.

Chicago↗
PubMed1990

Taurine transport in the in vitro perfused human placenta.

Taurine, required by the fetus for nutrition and neurological development, is inadequately synthesized by the fetus and substantial quantities of the amino acid are supplied by the mother. Maternal to fetal unidirectional taurine transport was studied in in vitro perfused human placentae from normal term deliveries. To determine whether the placenta can achieve and maintain a chemical gradient for taurine, recirculating equimolar maternal and fetal perfusions were performed. The ratio of fetal/maternal taurine concentration increased over 75 min and was maintained at 1.38 +/- 0.14 (SEM) through 2.25 h (n = 6). To determine the rate of taurine transport against a concentration gradient, flux was determined with maternal taurine constant at 50 microM whereas the fetal taurine concentration varied from 0 to 500 microM in a nonrecirculating system (n = 5). Despite increasing the chemical gradient tenfold, taurine was transported at a constant rate of 1.75 +/- 0.75 (SEM) nmol/min/g. Nonrecirculating perfusions were performed with B-alanine (n = 13) and hypotaurine (n = 10), both B-carrier competitors, and no inhibition of taurine transport could be detected, taurine flux being 104.1 +/- 6.0% (SEM) of baseline in the presence of B-alanine and 106.0 +/- 7.0% (SEM) with hypotaurine. Finally, ouabain inhibited transport (n = 3) by 58.1 +/- 5.4% (SEM). We conclude that taurine is transported in the human placenta by an active carrier mechanism.

Female↗
PubMed1989

Missed abortion: still appropriate terminology?

The term missed abortion has been in the obstetric literature more than 100 years. With ultrasonographic evaluation of early pregnancy, its textbook definition (death of a fetus without its expulsion for greater than or equal to 8 weeks) is rarely fulfilled. Yet the term missed abortion is still extensively used today with regard to early pregnancy losses. We recommend its abandonment and in its place the use of the following terms: first trimester intrauterine fetal death, second trimester intrauterine fetal death, and anembryonic gestation.

Abortion, Missed↗
PubMed1988

Dihydrotestosterone decreases beta-adrenergic receptor binding in the fetal rabbit lung.

Tritium-labeled dihydroalprenolol was used to quantify the beta-adrenergic receptor sites in day 30 fetal rabbit lung tissue. Each of the fetuses of New Zealand White rabbits on day 28 of gestation was injected with dihydrotestosterone (2.0 micrograms) in one horn of the uterus and 10% ethanol in normal saline (the solvent) in the contralateral one. The animals were sacrificed 48 hours later and the fetal lung tissue was assayed. Dihydrotestosterone decreased the beta-adrenergic receptor site number in the treatment group compared with the control group (86 versus 111 fmol/mg protein, p less than 0.05 by paired t-test). In the presence of dihydrotestosterone, beta-adrenergic receptor binding is inhibited in the preterm fetal rabbit. This effect may be implicated in the beta-adrenergic mediation of phospholipid synthesis and/or release by fetal alveolar cells.

Animals↗