Fetal cardiac dysfunction in preterm premature rupture of membranes.

BACKGROUND: Preterm premature rupture of membranes (PROM) is associated with one-third of preterm births. In about 50% of preterm PROM cases, the fetuses will elicit a fetal inflammatory response syndrome (FIRS). FIRS is associated with the impending onset of preterm labor, periventricular leukomalacia, neonatal sepsis, and long-term handicap, including the development of bronchopulmonary dysplasia and cerebral palsy. The fetal myocardium is a potential target organ of proinflammatory cytokines released during FIRS. The objective of this study was to determine whether preterm PROM is associated with functional changes in the fetal heart, as determined by fetal echocardiography. METHODS: A retrospective study was conducted to assess the diastolic function of fetuses with preterm PROM with documented microbial invasion of the amniotic cavity (n = 25), preterm PROM without microbial invasion of the amniotic cavity (n = 42), and fetuses from normal pregnancies (control group = 150). Pregnancies with multiple gestation, fetal distress, fetuses that were small for gestational age, and major congenital anomalies were excluded. Fetal echocardiography studies were performed with two-dimensional ultrasound, color Doppler imaging and pulsed Doppler ultrasound. Non-parametric statistics were used for comparisons. A p value of < 0.05 was considered significant. RESULTS: The prevalence of positive amniotic fluid cultures for micro-organisms in patients with preterm PROM was 35.8% (24/67). Ureaplasma urealyticum was the most frequent isolate, either alone (41.7%; 10/24) or with other micro-organisms (29.2%; 7/24). Fetuses with preterm PROM had a higher delta early diastolic filling/atrial contraction (E/A) peak velocity ratio, a higher delta E/A velocity-time integral (VTI) ratio, a lower delta A peak velocity, a lower delta A VTI, and a lower A VTI/total VTI ratio in the mitral valve compared to those with uncomplicated pregnancies. The delta E/A peak velocity ratio was significantly higher and the delta A VTI significantly lower in fetuses with preterm PROM and microbial invasion of the amniotic cavity than in those with preterm PROM without microbial invasion of the amniotic cavity. CONCLUSIONS: Preterm PROM is associated with changes in fetal cardiac function consistent with increased left ventricular compliance. These observations were also noted in fetuses with microbial invasion of the amniotic cavity. Our findings suggest that fetal cardiac function is altered in preterm PROM and, in particular, in cases with intra-amniotic infection.

Funisitis and chorionic vasculitis: the histological counterpart of the fetal inflammatory response syndrome.

OBJECTIVE: To determine whether there is a relationship between the presence of histological signs of inflammation in the extraplacental membranes and umbilical cord and the concentrations of fetal plasma interleukin-6 (IL-6). METHODS: The study examined a cohort of patients who were admitted with preterm labor or preterm premature rupture of the membranes (PROM) and who underwent cordocentesis. Inclusion criteria included fetal plasma available for IL-6 determination, histological examination of the umbilical cord and placenta, and delivery within 48 h of the procedure. This last criterion was used to preserve a meaningful temporal relationship between fetal plasma IL-6 and the results of histological examination of the placenta. Fetal plasma IL-6 was determined by a high sensitivity ELISA. Forty-five patients were available for study: 18 patients had preterm labor with intact membranes and 27 had preterm PROM. RESULTS: The incidence of funisitis was 44.4% (20/45): 27.8% (5/18) in patients with preterm labor and intact membranes and 55.6% (15/27) in patients with preterm PROM. The median values of fetal plasma IL-6 in patients with funisitis, chorioamnionitis without funisitis, and non-inflamed membranes were 51.4, 18.4 and 5.2 pg/ml, respectively. After log transformation of the fetal plasma IL-6 concentration, the means differed significantly from each other (ANOVA, p < 0.02). There was no difference in log fetal plasma IL-6 concentration between patients with funisitis and those with chorioamnionitis without funisitis. The difference in mean concentration of log fetal plasma IL-6 between patients with funisitis or chorionic vasculitis and those without inflammation was highly significant (post-hoc test, p = 0.01 and p < 0.01, respectively). Fetuses with fetal plasma IL-6 > 11 pg/ml had a significantly higher rate of histological signs of inflammation in the extra-placental membranes and umbilical cord than those with fetal plasma IL-6 < 11 pg/ml (funisitis: 55.6% (15/27) vs. 27.8% (5/18), p < 0.05; chorionic vasculitis: 55.6% (15/27) vs. 12.5% (2/16), p < 0.01; chorioamnionitis only: 25.9% (7/27) vs. 16.7% (3/18), p < 0.05; no inflammation: 18.5% (5/27) vs. 55.6% (10/18), p < 0.05, respectively). Fetuses with funisitis had significantly higher rates of clinical and histological chorioamnionitis, and neonatal infectious morbidity (proven + suspected sepsis) than fetuses without funisitis (40% (8/20) vs. 8% (2/25), 90% (18/20) vs. 36% (9/25), and 40% (8/20) vs. 4% (1/25), respectively; p < 0.01 for each). Fetuses with chorionic vasculitis had significantly higher rates of clinical and histological chorioamnionitis as well as neonatal infectious morbidity (proven + suspected sepsis) than fetuses without chorionic vasculitis (100% (17/17) vs. 42.3% (11/26), p < 0.01; 82.4% (14/17) vs. 50.0% (13/26), p = 0.05; and 41.2% (7/17) vs. 7.7% (2/26), p = 0.01). CONCLUSION: Fetal plasma IL-6 concentration is significantly associated with the presence of inflammatory lesions in the extraplacental membranes and umbilical cord. Fetuses with fetal plasma IL-6 > 11 pg/ml had a significantly higher rate of funisitis and/or chorionic vasculitis than fetuses with fetal plasma IL-6 < 11 pg/ml. These findings suggest that funisitis/chorionic vasculitis is the histological manifestation of the fetal inflammatory response syndrome.

Severe pre-eclampsia remote from term: what to expect of expectant management.

OBJECTIVE: To describe the duration of expectant management and the indications for termination of expectant management of pregnancies complicated by severe pre-eclampsia remote from term. STUDY DESIGN: We identified pregnancies complicated by severe pre-eclampsia diagnosed between 24 weeks and 31 weeks 6 days at our institution in 1991-98. Pertinent clinical data were obtained from review of maternal and neonatal charts. Comparison of patients was based on the duration of time from admission to delivery: < 48 h (group 1), 48 h to 7 days (group 2), and > or = 7 days (group 3). RESULTS: A total of 142 women met all study criteria. Seventy-nine (55.6%) women were delivered within 48 h, 42 (29.6%) between 48 h and 7 days, and 21 (14.8%) at > or = 7 days from diagnosis. Of group 1 patients (< 48 h), 59 (74.7%) were delivered for maternal indications while 20 (25.3%) were delivered for fetal indications. Of group 2 patients (48 h to 7 days), 35 (83.3%) were delivered for maternal indications while seven (16.7%) were delivered for fetal indications. Of group 3 patients (> or = 7 days), 16 (76.2%) were delivered for maternal indications while five (23.8%) were delivered for fetal indications. There were no significant differences in the indications for delivery based on the duration from admission to delivery. CONCLUSIONS: Despite an aggressive approach towards expectant management of preterm pregnancies complicated by severe pre-eclampsia, most patients were delivered within 48 h for maternal indications.

The effect of intrapartum magnesium sulfate therapy on fetal cardiac troponin I levels at delivery.

OBJECTIVE: To determine whether intrapartum magnesium sulfate (MgSO4) therapy for seizure prophylaxis in pre-eclampsia-eclampsia is associated with biochemical evidence of subacute fetal myocardial damage at delivery. STUDY DESIGN: Troponin I, a cardiac-specific protein used to detect myocardial injury, was measured from the umbilical vein at delivery in term pregnancies complicated by pre-eclampsia and uncomplicated control pregnancies. Women with pre-eclampsia received intravenous MgSO4 as a 6-g load followed by 2 g/hour until delivery. Clinical characteristics and fetal troponin levels were compared between groups. RESULTS: There was no difference in troponin I concentrations between term patients with intrapartum MgSO4 therapy and controls who did not receive MgSO4 (median 0.86 ng/ml, range 0.72-1.10 vs. 0.89 ng/ml, range 0.68-1.50; p = 1.0). There was also no statistically significant difference in the number of patients with a troponin I level of > or = 1.0 ng/ml between groups (30.8% (4/13) vs. 15.4% (4/26); p = 0.4). CONCLUSIONS: Our findings suggest that, in term fetuses that are not growth impaired, exposure to intrapartum MgSO4 is not associated with subacute myocardial injury.

Relationship between fetal pulmonary maturity assessment and neonatal outcome in premature rupture of the membranes at 32-34 weeks' gestation.

The absence of fetal pulmonary maturity in patients with preterm premature rupture of the membranes (PPROM) is often considered an indication for conservative management. The purpose of this study was to examine the value of biochemical pulmonary maturity assessment for the prediction of neonatal outcome in patients with PPROM between 32 and 34 weeks' gestation. Pregnancies complicated by PPROM at 32 to 34 weeks' gestation that delivered from January 1995 to May 2000 and had biochemical pulmonary maturity assessment were reviewed. Patients with medical disorders, multiple gestations, fetal growth restriction or structural anomalies, or evidence of intra-amniotic infection were excluded. Neonatal outcome measures were compared between patients with mature and immature pulmonary indices. During this time period, 244 patients with PPROM at 32-34 weeks' gestation were delivered; 78 patients met inclusion criteria (n = 41 patients with mature indices and n = 37 patients with immature indices). There were no cases of perinatal death or sepsis. There was no difference in major neonatal morbidities including need for mechanical ventilation, grade 2 or 3 necrotizing enterocolitis, grade 3 or 4 intraventricular hemorrhage, or seizures. After controlling for confounding factors including gestational age at PPROM and delivery, latency period, group B streptococcus (GBS) vaginal colonization, corticosteroid therapy, neonatal sex, mode of delivery, fetal indications for delivery, and umbilical cord pH, biochemical pulmonary maturity was not predictive of major neonatal morbidity. In our population, biochemical pulmonary maturity status does not appear to be predictive of neonatal morbidity in pregnancies complicated by PPROM at 32-34 weeks' gestation.

A role for the 72 kDa gelatinase (MMP-2) and its inhibitor (TIMP-2) in human parturition, premature rupture of membranes and intraamniotic infection.

OBJECTIVE: Degradation of the extracellular matrix in fetal membranes has been implicated in the process of parturition and rupture of membranes. Matrix metalloproteinases (MMPs) are enzymes capable of degrading extracellular matrix including collagen. Tissue inhibitors of matrix metalloproteinases (TIMPs) inhibit the activity of MMPs by covalently binding to the enzymes. MMP-2 degrades Type IV collagen and TIMP-2 is its specific inhibitor. The objective of this study was to determine if human parturition, rupture of membranes (term and preterm) and microbial invasion of the amniotic cavity (MIAC) are associated with changes in the concentrations of MMP-2 and TIMP-2 in amniotic fluid. STUDY DESIGN: A cross-sectional study was conducted with women in the following categories: 1) term with intact membranes, in labor and not in labor; 2) preterm labor and intact membranes who delivered at term, who delivered preterm and preterm labor with MIAC; 3) preterm premature rupture of membranes (PROM) with and without infection; 4) term and preterm PROM not in labor; and 5) midtrimester. MMP-2 and TIMP-2 concentrations in amniotic fluid were determined using sensitive and specific immunoassays. RESULTS: The concentration of TIMP-2 increased with advancing gestational age (r = 0.6, p < 0.001). No correlation was found between MMP-2 concentrations and gestational age. Human parturition and rupture of membranes (term and preterm) and in patients with intact membranes were not associated with changes in the amniotic fluid MMP-2 concentrations. In contrast, 1) patients with spontaneous labor (term and preterm) had significantly lower median concentrations of TIMP-2 compared to those not in labor (p < 0.05 for both); 2) MIAC in women with preterm labor and preterm PROM was associated with a significant decrease in amniotic fluid TIMP-2 concentrations (p < 0.04 for both comparisons); 3) Rupture of the membranes (term and preterm) was also associated with a significant decrease in the amniotic fluid TIMP-2 concentrations (p < 0.05 and p < 0.03, respectively). CONCLUSIONS: Human parturition (preterm and term), rupture of fetal membranes (term and preterm) and intraamniotic infection are associated with a significant decrease in amniotic fluid TIMP-2 concentrations.

Meconium aspiration syndrome in term neonates with normal acid-base status at delivery: is it different?

OBJECTIVE: Our aim was to compare the clinical characteristics of meconium aspiration syndrome in cases with pH > or =7.20 and in those with pH <7.20. STUDY DESIGN: Medical records of diagnostic codes from the International Classification of Diseases, Ninth Revision, were used to identify neonates with severe meconium aspiration syndrome who had been delivered at our institution from 1994 through 1998. Severe meconium aspiration syndrome was defined as a mechanical ventilator requirement of >48 hours. Clinical data including neonatal outcomes of cases of meconium aspiration syndrome associated with umbilical pH > or =7.20 at delivery were compared with data on outcomes of cases with pH <7.20. RESULTS: During this 4-year study period, 4985 singleton term neonates were delivered through meconium-stained amniotic fluid. Forty-eight cases met all study criteria, and pH values at delivery were as follows: pH > or =7.20, n = 29, and pH <7.20, n = 19. There were no differences between groups in the incidence of clinical chorioamnionitis, in the presence of meconium below the vocal cords, or in birth weight. Neonates with meconium aspiration syndrome and umbilical pH > or =7.20 at delivery developed seizures as often as those with pH <7.20 (20.1% vs 21.1%; P = 1.0). CONCLUSION: Normal acid-base status at delivery is present in many cases of severe meconium aspiration syndrome, which suggests that either a preexisting injury or a nonhypoxic mechanism is often involved.

Nucleated red blood cell counts in term neonates with umbilical artery pH < or = 7.00.

The purpose of this study was to determine whether nucleated red blood cell (NRBC) counts are elevated in term neonates who have severe fetal acidemia at birth. The neonatal NRBC counts of term (gestational age > or = 37 weeks) neonates with pathological acidemia were compared with those from control neonates who met the following criteria: gestational age > or = 37 weeks, birth weight > or = 2800 g, umbilical artery pH > or = 7.25, and a 5-minute APGAR > 7. Pathological acidemia was defined as an umbilical artery pH < or = 7.0 and a base excess > -12 mEq/L. Twenty-six neonates met all inclusion criteria and were compared to 78 controls. The mean NRBC/100 WBC was 11.9 +/- 13.5 (range 0 to 45) for acidemic neonates compared to 3.9 +/- 2.9 NRBC/100 WBC (range 0 to 11) for control neonates [p <0.001]. Our findings suggest that the onset of hypoxia-ischemia in pregnancies complicated by severe fetal acidemia often begins prior to the intrapartum period.

Effects of intra-amniotic meconium exposure on the fetal rat: development of a pathogenic model.

OBJECTIVE: To develop an in vivo animal model for the study of the effects of intrauterine meconium exposure on the fetus. METHODS: Timed pregnant Long-Evans rats were purchased on gestational day (GD) 12 and allowed to acclimate for at least 48 h prior to surgery. Laparotomy was performed and both uterine horns were exteriorized through the abdominal incision. A 26-gauge needle was used to inject either 0.1-cm(3) sterile normal saline or a 20% meconium suspension into each individual gestational sac. The uterus was returned to the abdomen and the incision was closed. On GD 21 (term = 21 days) a cesarean section was completed and the number and viability of fetuses in each horn were recorded. RESULTS: A total of 14 animals were involved in this pilot study. One rat underwent sham surgery with only intra-amniotic saline injection and 13/15 fetuses survived to term. Two animals that underwent surgery on day 18 expired < 24 h postinjection. Eleven maternal animals were injected on GD 20 and underwent cesarean delivery at term; survival rates for saline-injected animals were 71.2% compared to 66.2% for meconium-exposed fetuses. CONCLUSION: We have established an in vivo animal model that allows for the examination of the effects of prolonged intrauterine meconium exposure on the fetus.

Meconium staining and meconium aspiration syndrome. Is there seasonal variation?

OBJECTIVE: To determine whether the incidence of pregnancies complicated by meconium-stained amniotic fluid (MSAF) or meconium aspiration syndrome (MAS) differs with seasonal changes. METHODS: An established perinatal database was used to identify all term (> or = 37 weeks) singleton gestations resulting in a live birth from January 1, 1997 to December 31, 1999. Patients were divided into groups based on the season of delivery: winter (December-February), spring (March-May), summer (June-August), and fall (September-November). Rates of MSAF (%MSAF/total deliveries) and MAS (%MAS/total deliveries) were calculated and compared among seasons. Local climatic data (average monthly temperature and monthly precipitation) were obtained from the National Weather Service. Multiple logistic regression analysis was performed to control for the effects of confounding variables and odds ratio (OR) with 95% confidence intervals (CI) were calculated. p < 0.05 was considered significant. RESULTS: Over the 3-year study period there were a total of 14,888 deliveries meeting the criteria. MSAF occurred in 3,206 (21.5%) deliveries and MAS developed in 92 (0.6% of total, 2.9% of MSAF). There were no differences in the rate of MSAF (p = 0.2) or MAS (p = 0.6) between seasons. By logistic regression neither season, temperature, nor precipitation were associated with MSAF or MAS. CONCLUSIONS: Our findings suggest that over the period examined there were no significant seasonal variations in the incidence of MSAF or MAS.

The effects of intrapartum magnesium sulfate therapy on fetal serum interleukin-1beta, interleukin-6, and tumor necrosis factor-alpha at delivery: a randomized, placebo-controlled trial.

OBJECTIVE: Elevated levels of inflammatory cytokines in the fetus have been linked to neurologic morbidities in preterm neonates. Magnesium sulfate is currently being studied in clinical trials as a potential fetal neuroprotective agent. The purpose of this study was to determine whether intrapartum magnesium sulfate therapy has an effect on the umbilical venous concentrations of interleukin-1beta, interleukin-6, and tumor necrosis factor-alpha at delivery. STUDY DESIGN: Women with singleton gestations >32 weeks with no clinical indications for magnesium sulfate therapy (preeclampsia or tocolysis) and either clinical chorioamnionitis or prolonged rupture of membranes were recruited for the study. Consenting patients were randomly assigned, in a double-blinded fashion, to receive either magnesium sulfate (6-g load then 2 g/hr) or matched volumes of lactated Ringer's solution until delivery. Fetal blood specimens were obtained by aspiration of the umbilical vein after cord clamping but before placental separation. Umbilical cytokine levels were measured with a sensitive and specific immunoassay. RESULTS: Twenty-two patients were randomly assigned to groups and received either magnesium sulfate (n = 11) or placebo (n = 11). There were no differences in the demographic or clinical characteristics between groups. The umbilical venous ionized magnesium concentration was significantly higher in the magnesium sulfate group (2.32 +/- 0.27 mg/dL vs 1.23 +/- 0.15 mg/dL; P <.001). There were no statistically significant differences between groups with respect to umbilical levels of interleukin-1beta (1.5 pg/mL [1.5-58] vs 1.5 pg/mL [1.5-10]; P =.5); interleukin-6 (8.5 pg/mL [1-1000] vs 11.2 pg/mL [1-113]; P =.9); or tumor necrosis factor-alpha (16 pg/mL [7.6-20.3] vs 16.6 pg/mL [8.3-22.2]; P =.5). CONCLUSION: In this pilot study the intrapartum administration of magnesium sulfate does not appear to affect the concentration of inflammatory cytokines in fetal blood at delivery.

Does cervical cerclage prevent preterm delivery in patients with a short cervix?

OBJECTIVE: Our purpose was to determine whether cerclage placement in women with a short cervix on transvaginal ultrasonography reduces the rate of preterm delivery. STUDY DESIGN: A retrospective cohort study identified patients with an ultrasonographic short cervix (cervical length < or =15 mm) between 14 and 24 weeks' gestation. Cerclage placement was performed at the discretion of the attending physician. Clinical characteristics and outcome with and without cerclage were compared. RESULTS: Seventy patients met inclusion criteria; 25 (36%) underwent cerclage placement. Patients managed with cerclage had a lower gestational age at diagnosis (19.6 weeks vs 21.3 weeks, P <.01) but had a similar median cervical length, presence of funneling, and a history of cervical surgery, in comparison with those managed without cerclage. The rate of spontaneous preterm delivery was not different between groups. Patients with cerclage had a higher rate of preterm premature rupture of membranes than those without cerclage (65.2% vs 36.4%, P <.05). CONCLUSION: Cervical cerclage in patients with a short cervix did not reduce the rate of spontaneous preterm delivery and increased the risk of preterm premature rupture of membranes.

Relationship between the sonographic pattern of intrauterine growth restriction and acid-base status at the time of cordocentensis.

OBJECTIVE: To determine whether there is a difference in acid-base status at the time of cordocentesis between fetuses with symmetric and asymmetric intrauterine growth restriction (IUGR). STUDY DESIGN: Non-anomalous singleton fetuses with IUGR who underwent fetal blood sampling for rapid karyotype analysis from 1992-1995 were retrospectively identified. Cases with gestational age <24 weeks, abnormal karyotype, or evidence of congenital infection were excluded. Fetuses were divided into two groups based on Head Circumference/ Abdominal Circumference Ratio (HC/AC). The asymmetric-IUGR group had HC/AC > or = 95% tile for GA, and the symmetric-IUGR group had HC/AC <95% tile. GA adjusted values of umbilical venous pH, pCO2, pO2, HCO3, hemoglobin and reticulocyte count were calculated by subtracting the mean values for GA from the observed and compared between groups. RESULTS: Both symmetric-IUGR (n = 7) and asymmetric-IUGR (n = 9) had umbilical venous pH and pO2, levels lower than GA normative values. However, there were no differences between groups for any of the parameters studied. CONCLUSIONS: Fetuses with symmetric and asymmetric IUGR due to UPI display a similar degree of acid-base impairment.

Further observations on the fetal inflammatory response syndrome: a potential homeostatic role for the soluble receptors of tumor necrosis factor alpha.

OBJECTIVE: The fetal inflammatory response syndrome is a subclinical condition frequently present in preterm labor and preterm premature rupture of the membranes and is associated with increased perinatal morbidity and mortality. Tumor necrosis factor alpha is a mediator of septic shock and death, and it exerts its biologic effects by interacting with 2 receptors, TNF-R1 and TNF-R2. Soluble tumor necrosis factor receptors can buffer the biologic activity and protect against the deleterious effects of tumor necrosis factor alpha. The purpose of this study was to determine the behavior of soluble tumor necrosis factor receptors in fetuses with and without fetal inflammatory response syndrome. STUDY DESIGN: Fetal blood sampling was performed in patients with preterm labor (n = 95) and preterm premature rupture of the membranes (n = 39). Control samples were obtained from fetuses who were undergoing blood sampling for clinical indications and had normal outcomes (n = 21). Fetal inflammatory response syndrome was defined as a fetal plasma interleukin 6 concentration >11 pg/mL. Concentrations of interleukin 6 and TNF-R1 and TNF-R2 were determined by use of sensitive and specific immunoassays. Analysis of covariance was used for statistical analysis. RESULTS: (1) TNF-R1 and TNF-R2 were detectable in all samples, and their concentrations decreased with advancing gestational age (r = -0.8 and r = -0.7; P<.0001 and P<.001, respectively). (2) The mean fetal plasma concentrations of TNF-R1 and TNF-R2 were significantly higher in fetuses with fetal inflammatory response syndrome than in those without the syndrome after adjustment for gestational age and fetal membrane status (TNF-R1: no fetal inflammatory response syndrome, mean +/- SE, 3473.7+/-128.8 pg/mL; vs fetal inflammatory response syndrome, mean +/- SE, 4079.9+/-190.7 pg/mL; P<.005; TNF-R2: no fetal inflammatory response syndrome, mean +/- SE, 6033.2+/-235.4 pg/mL; vs. fetal inflammatory response syndrome, mean +/- SE, 7783.1+/-342.8 pg/mL; P<.0001). (3) Fetuses of patients who delivered within 72 hours of cordocentesis had significantly higher concentrations of TNF-R1 and TNF-R2 receptors than those with longer latency periods (P<.05 for each). CONCLUSION: The fetal inflammatory response syndrome is associated with increased availability of the soluble receptors of tumor necrosis factor alpha in fetal plasma. These factors may attenuate the deleterious effects of tumor necrosis factor alpha.

Influence of maternal-fetal medicine subspecialization on the frequency of trial of labor in term pregnancies with breech presentation.

OBJECTIVE: To investigate the role of subspecialization in maternal-fetal medicine (MFM) on the frequency of a trial of labor in term pregnancies with breech presentation. METHODS: We conducted a retrospective study of 332 singleton pregnancies > or =37 weeks with nonfootling breech presentation that delivered over a 6-year period (1994-1998) at a university-based, tertiary care hospital. Patients were divided into two groups based on whether the delivery was attended by an MFM or non-MFM obstetrician-gynecologist. Demographic and clinical data were compared between groups and outcome variables included whether the patient had an attempt at vaginal delivery, cesarean delivery after a labor attempt, or vaginal breech delivery. RESULTS: The frequency of labor attempt (OR 1.4, 95% CI 0.9-2.3), vaginal breech success rate (OR 0.6, 95% CI 0.3-1.5), and overall cesarean rates (OR 0.9, 95% CI 0.5-1.7) were similar between groups. Using discriminant function analysis, only nulliparity (R2 = 1.6%, F = 6.0, P = 0.005) and birthweight (R2 = 2.0% F = 6.4, P = 0.01) were associated with trial of vaginal delivery. CONCLUSIONS: Subspecialization in MFM had no impact on the frequency of trial of labor in the term pregnancy with a breech presentation.

Why are cesarean delivery rates so high in diabetic pregnancies?

AIMS: The purpose of this study was to examine factors relevant to mode of delivery in term pregnancies complicated by gestational and pre-gestational diabetes. METHODS: A retrospective chart review of term (> or = 37 weeks) singleton pregnancies complicated by Class A2 through Class R pregnancies which delivered from 1991-1997 was performed. Exclusion criteria were prior cesarean delivery, non-vertex presentation, fetal structural defects, or any contraindications to vaginal delivery. Maternal and fetal factors relevant to mode of delivery were examined and compared. Stepwise logistic regression analysis was performed to examine factors predictive of delivery mode. RESULTS: A total of 148 patients met study criteria. Induction rates were 60.9% for gestational and 79.8% for pre-gestational diabetics. The overall cesarean delivery rate by Diabetes Class for A2, B, C, D-F pregnancies was 20.3%, 40%, 37%, and 57.1% respectively. In Class A2 pregnancies no factor was associated with cesarean delivery and only nulliparity (p = 0.03) was associated in Class B-F pregnancies. CONCLUSIONS: These results suggest that physician factors may play an important role in the risk for cesarean delivery in our diabetic population.

Mathematic modeling to predict abruptio placentae.

OBJECTIVE: This study was undertaken to identify correlates of abruptio placentae and to develop a mathematic model for the prediction of abruptio placentae. STUDY DESIGN: A total of 170,258 singleton birth records from 1991 to 1996 contained in the Schleswig-Holstein perinatal database were analyzed. Fifty-two recognized obstetric risk factors were subjected to univariate analysis. Correlates of abruptio placentae then underwent stepwise forward binary logistic regression. A constant value B(0), coefficients B(1) through B(p), an odds ratio, and a 95% confidence interval were calculated for individual correlates. RESULTS: Abruptio placentae occurred in 874 of 170,258 singleton gestations (0.5%). Of the 52 risk factors 31 proved to be correlates of abruptio placentae, with 16 among primiparous women and 25 among multiparous women. Ten correlates for primiparous, women and 13 for multiparous women emerged from the linear regression, with 7 correlates being shared by both primiparous and multiparous women. CONCLUSION: The probability that abruptio placentae will occur (p) can be calculated according to the following expression: p = e (z)/(1 + e (z)), where z = B(0) + B(1), em leaderB(p). For example, for a primiparous woman who smokes with bleeding at >28 weeks' gestation and a male fetus in the breech position, the following calculation would yield the chance of abruptio placentae:z = -2.25 + 2.51 + 0.41 + 0.24 + 0.60 = 1.51; p = e (1.51)/ (1 + e (1.51)) = 4. 53/5.53 = 0.82, or 82%.

Patients with an ultrasonographic cervical length < or =15 mm have nearly a 50% risk of early spontaneous preterm delivery.

OBJECTIVE: The aim of this study was to determine the value in the prediction of spontaneous preterm delivery of ultrasonographically measured cervical length measured between 14 and 24 weeks' gestation. STUDY DESIGN: A retrospective cohort study examined cervical length by means of a two-stage procedure, transabdominal ultrasonography followed by transvaginal ultrasonography if cervical length was <30 mm. RESULTS: A total of 6877 patients met inclusion criteria. Mean cervical length was 37.5 mm. Odds ratios for early preterm delivery (< or =32 weeks' gestation) for patients with cervical lengths < or =10, < or =15, < or = 20, < or =25, and < or =30 mm were, respectively, 29.3 (95% confidence interval, 11.3-75.8), 24.3 (95% confidence interval, 12. 9-45.9), 18.3 (95% confidence interval, 10.8-31.0), 13.4 (95% confidence interval, 8.8-20.6), and 3.2 (95% confidence interval, 2. 4-4.4). For early preterm delivery a cervical length of < or =15 mm had a positive predictive value of 47.6%, a negative predictive value of 96.7%, a sensitivity of 8.2%, and a specificity of 99.7%. CONCLUSIONS: A short cervix seen on a second-trimester sonogram was a powerful predictor of early spontaneous preterm delivery (< or =32 weeks' gestation). Nearly 50% of patients with a cervical length < or =15 mm had an early spontaneous preterm delivery, which suggests that clinical trials of interventions (eg, cerclage) in this population are urgently needed.

The relationship between nucleated red blood cell counts and early-onset neonatal seizures.

OBJECTIVE: This study was undertaken to better define the timing of neurologic insult in neonates with early-onset seizures through evaluation of neonatal nucleated red blood cell levels. STUDY DESIGN: Medical records and the International Classification of Diseases, Ninth Revision codes were used to identify all term neonates with neonatal convulsions who were delivered at our institution (January 1, 1990-December 31, 1995). Each neonate with early-onset seizures was matched to the next 3 neonates who met the following criteria: gestational age > or =37 weeks, no early-onset seizures, birth weight > or =800 g, umbilical artery pH > or =7.25, and a 5-minute Apgar score >7. Demographic characteristics, clinical factors, and mean initial nucleated red blood cell counts were compared between groups. RESULTS: During the 6-year study period, there were a total of 36, 490 singleton term deliveries of infants who were alive at birth. Forty-five (0.1%) of these neonates had early-onset seizures. Thirty neonates with early-onset seizures met the inclusion criteria. Mean nucleated red blood cell counts (number of nucleated red blood cells per 100 white blood cells) for neonates with early-onset seizures were significantly increased compared with those of control neonates (18.4 +/- 22.0 vs 4.6 +/- 4.5; P <.0008). CONCLUSIONS: Our findings are suggestive of the hypothesis that neurologic injury leading to early-onset seizures often occurs before the intrapartum period.