Preterm Cesarean Delivery Research Articles

449: The role of betamethasone and fetal lung maturity testing in late preterm cesarean deliveries

Respiratory morbidity (RM) remains a leading cause of neonatal intensive care (NICU) admissions in late preterm infants, especially those born by cesarean delivery (CD). Recent evidence suggests antenatal betamethasone (BMZ) may reduce RM in this group. Our objective was to evaluate the benefit of BMZ or assessment of fetal lung maturity (FLM) when planning CD in the late preterm infant.

OP32.05: Estimated fetal weight Z-score and amniotic fluid index as predictors of neonatal respiratory distress syndrome in indicated Cesarean preterm delivery

OP32.05: Estimated fetal weight Z-score and amniotic fluid index as predictors of neonatal respiratory distress syndrome in indicated Cesarean preterm delivery

Previous Preterm Cesarean Delivery and Risk of Subsequent Uterine Rupture

Previous Preterm Cesarean Delivery and Risk of Subsequent Uterine Rupture

Previous Preterm Cesarean Delivery and Risk of Subsequent Uterine Rupture

To determine if women with a history of a previous preterm cesarean delivery experienced an increased risk of subsequent uterine rupture compared with women who had a previous nonclassic term cesarean delivery. A prospective observational study was performed in singleton gestations that had a previous nonclassic cesarean delivery from 1999 to 2002. Women with a history of a previous preterm cesarean delivery were compared with women who had a previous term cesarean delivery. Women who had both a preterm and term cesarean delivery were included in the preterm group. A prior preterm cesarean delivery was significantly associated with an increased risk of subsequent uterine rupture (0.58% compared with 0.28%, P<.001). When women who had a subsequent elective cesarean delivery were removed (remaining n=26,454) women with a previous preterm cesarean delivery were still significantly more likely to sustain a uterine rupture (0.79% compared with 0.46%, P=.001). However, when only women who had a subsequent trial of labor were included, there was still an absolute increased risk of uterine rupture, but it was not statistically significant (1.00% compared with 0.68%, P=.081). In a multivariable analysis controlling for confounding variables (oxytocin use, two or more previous cesarean deliveries, a cesarean delivery within the past 2 years, and preterm delivery in the current pregnancy), patients with a previous preterm cesarean delivery remained at an increased risk of subsequent uterine rupture (P=.043, odds ratio 1.6, 95% confidence interval 1.01-2.50) compared with women with previous term cesarean delivery. Women who have had a previous preterm cesarean delivery are at a minimally increased risk for uterine rupture in a subsequent pregnancy when compared with women who have had previous term cesarean deliveries.

The epidemiology of pregnancy-associated emergency department injury visits and their impact on birth outcomes

Objective Describe the demographics, injury types, mechanisms, and intents of emergency department (ED) injury visits by pregnant women and to quantify their risk of adverse birth outcomes. Methods Through a retrospective cohort study design, Utah ED, birth, and fetal death records were probabilistically linked to identify women seen in an ED with an injury during pregnancy among births and fetal deaths from 1999 to 2002. Logistic regression was used to assess the effect of having an injury-related ED visit on various adverse pregnancy outcomes. Results 7350 (3.9%) women experienced an injury-related ED visit during pregnancy. Motor vehicle occupant injuries were the leading mechanism of ED injury visits (22.4%). Controlling for known risks, pregnant women with an injury-related ED visit were more likely than non-injured pregnant women to experience preterm labor (OR = 1.22, 95% CI = 1.12–1.34), placental abruption (OR = 1.33, 95% CI = 1.08–1.65), and cesarean delivery (OR = 1.27, 95% CI = 1.19–1.36). Infants born to women who were injured during pregnancy were more likely to be born preterm (OR = 1.23, 95% CI = 1.12–1.34) and have low birth weight (OR = 1.22, 95% CI = 1.1–1.35). Conclusions Most injured pregnant women are treated and released from the ED; however, significant increased risks remain for several maternal complications and birth outcomes.

Recurrence of Henoch–Schönlein purpura nephritis superimposed on severe pre‐eclampsia in a kidney transplant patient

Abstract: Henoch–Schönlein purpura nephritis (HSPN) frequently recurs in patients following kidney transplantation, and pregnancy has been reported to be an exacerbating factor. However, little is known about the recurrence of HSPN during pregnancy in patients with superimposed pre‐eclampsia having excellent graft function who had experienced kidney transplantation. Here, we report a case of recurrent HSPN complicating severe pre‐eclampsia six yr after transplantation. A 31‐yr‐old woman who had received a living‐related kidney transplant at age 25 became pregnant. The cause of her end‐stage renal disease was biopsy‐proven HSPN. She had an excellent clinical course after transplantation, with good allograft function (serum creatinine &lt;0.9 mg/dL, no proteinuria or hematuria, no episode of rejection), and normal blood pressure. We discontinued the angiotensin II receptor blocker that had been prescribed to prevent glomerular hyperfiltration. After week 17 of pregnancy, proteinuria and blood pressure increased markedly, and then her kidney function deteriorated progressively with intermittent mild microhematuria. At week 28 of pregnancy, umbilical blood flow and fetal growth were impaired, prompting preterm cesarean delivery. Subsequently, her blood pressure and serum creatinine normalized immediately, although the urinary protein excretion decreased insufficiently from 6.0 to 1.0 g/d at six months postpartum. In general, hematuria has a predictive value for the recurrence of HSPN. Clinically, we considered this case to be superimposed pre‐eclampsia, not recurrent HSPN. However, a biopsy conducted seven months postpartum suggested recurrent HSPN on her renal allograft. In addition, focal segmental membranous nephropathy with C1q deposition was observed. It was difficult to determine when the HSPN and membranous lesions occurred. This case suggests that a pathological evaluation is important in HSPN patients after transplantation to reduce adverse risks during and after pregnancy.

Labor (Term and Preterm) Is Associated With Changes in the Placental mRNA Expression of Corticotrophin-Releasing Factor

Because maternal plasma corticotrophin-releasing factor (CRF) levels increase during the last weeks of pregnancy and at parturition, the present study evaluated whether placental mRNA expression of CRF and CRF-binding protein (CRF-BP) are modified in preterm delivery. A group of 30 women with singleton pregnancies were enrolled in the study. A placental tissue specimen was collected from pregnant women (1) at term after cesarean delivery (39.3 +/- 0.1 gestational weeks; n = 10), (2) at term after spontaneous vaginal delivery (40.1 +/- 0.2 gestational weeks; n = 10), or (3) at preterm delivery (32.4 +/- 0.4 gestational weeks; n = 10). Changes of placental mRNA expression were evaluated by real-time quantitative reverse transcriptase polymerase chain reaction analysis. Placental CRF mRNA expression at term (P < .001) and preterm delivery (P < .001) was significantly higher than in cesarean delivery and highest in preterm placentas. With respect to CRF-BP, no significant difference in placental mRNA expression was observed among samples collected after term or preterm delivery and cesarean delivery. The present study showed for the first time that both term and preterm labor are associated with increased expression of placental CRF but not CRF-BP mRNA.

Indomethacin prophylaxis or expectant treatment of patent ductus arteriosus in extremely low birth weight infants?

Indomethacin prophylaxis or expectant treatment are common strategies for the prevention or management of symptomatic patent ductus arteriosus (sPDA). To compare the clinical responses of extremely low birth weight (ELBW) infants to indomethacin prophylaxis with that of other infants who were managed expectantly by being treated with indomethacin or surgically only after an sPDA was detected. Retrospective cohort investigation of 167 ELBW infants who received indomethacin prophylaxis (study) and 167 ELBW infants (control) treated expectantly who were matched by year of birth (1999 to 2006), birth weight, gestational age (GA) and gender. Mothers of the two groups of infants were comparable demographically and on the history of preterm labor, pre-eclampsia, antepartum steroids and cesarean delivery. Study and control infants were similar in birth weight, GA, low 5 min Apgar scores, surfactant administration, the need for arterial blood pressure control, bronchopulmonary dysplasia and neonatal mortality. Necrotizing enterocolitis, spontaneous intestinal perforations, intraventricular hemorrhage grade III to IV, periventricular leukomalacia and stage 3 to 5 retinopathy of prematurity occurred also with similar frequency in both groups of infants. In the indomethacin prophylaxis group, 29% of the infants developed sPDA, and of them 38% responded to indomethacin treatment. In the expectantly treated group, 37% developed sPDA, and of them 59% responded to indomethacin treatment. Overall, surgical ligation rate for sPDA was similar between both groups of patients. In our experience, indomethacin prophylaxis does not show any advantages over expectant early treatment on the management of sPDA in ELBW infants. Although no deleterious effects were observed, prophylaxis exposed a significant number of infants who may have never developed sPDA, to potential indomethacin-related complications.

The effect of pre-pregnancy body mass index and gestational weight gain on pregnancy outcomes in urban care settings in Urmia-Iran

BackgroundNutritional status of women has been considered an important prognostic indicator of pregnancy outcomes. Few studies have evaluated patterns of weight gain and pre-pregnancy body mass index in developing regions where malnutrition and poor weight gain as well as maternal obesity have significant influences on the pregnancy outcome. This study aims to show effect of pregnancy body mass index and the corresponding gestational weight gain on the outcome of pregnancy.MethodsOn a prospective cross sectional study, two hundred and seventy women from urban areas of Northwest Iran were recruited for participation during their first eight weeks of pregnancy. Body mass index (BMI) was categorized and gestational weight gain was divided into two groups of normal and abnormal based on recommendations of Institute of Medicine (IOM) published in 1990. Chi square and one way ANOVA were used in the univariate analysis of the association between weight gain and corresponding adverse outcomes including cesarean, preterm labor and low neonatal birth weight. Adjusted odds ratios for adverse outcomes were determined by multiple logistic regression models, while controlling for the following factors: maternal age, parity, and education.ResultsBoth pre-pregnancy BMI < 19 and abnormal weight gain during pregnancy were found to be associated with low neonatal birth weight defined as < 2500 g. Abnormal weight gain, during pregnancy was not related to an increased risk of preterm labor or cesarean delivery but it was highly associated with low birth weight (LBW)(P < 0.05).ConclusionLow pre-pregnancy BMI is an established risk factor for LBW. Abnormal gestational weight gain may further complicate the pregnancy as an additional risk factor for neonatal LBW. All women, regardless of their pre-pregnancy BMI may be at risk for abnormal weight gain and hence low birth weight. Pre-pregnancy and gestation nutritional assessments remain significant part of all prenatal visits.

Spinal Anesthesia-Induced Hypotension: A Risk Comparison Between Patients With Severe Preeclampsia and Healthy Women Undergoing Preterm Cesarean Delivery

Spinal Anesthesia-Induced Hypotension: A Risk Comparison Between Patients With Severe Preeclampsia and Healthy Women Undergoing Preterm Cesarean Delivery

The MFMU cesarean registry: Previous preterm low transverse cesarean delivery and risk of subsequent uterine rupture

Preterm low transverse cesarean delivery (pLTCD) is often performed on an unlabored uterus with a poorly developed lower uterine segment, potentially leading to an unsuspected incision in the contractile portion of the uterus. We sought to determine if a previous pLTCD was associated with an increased risk of subsequent uterine rupture.

Spinal Anesthesia-Induced Hypotension: A Risk Comparison Between Patients with Severe Preeclampsia and Healthy Women Undergoing Preterm Cesarean Delivery

Spinal Anesthesia-Induced Hypotension: A Risk Comparison Between Patients with Severe Preeclampsia and Healthy Women Undergoing Preterm Cesarean Delivery

Previous preterm cesarean delivery: Identification of a new risk factor for uterine rupture in VBAC candidates

Objective. A major risk of trials of labor in patients with prior cesarean delivery is uterine rupture. We evaluated the question of whether a previous cesarean delivery at an early gestational age predisposes the patient to subsequent uterine rupture.Methods. This was a retrospective chart review of patients delivering at North Shore University Hospital with a trial of labor after previous cesarean delivery to ascertain all cases of uterine rupture. Patients who had had a previous cesarean delivery at our institution who did not suffer uterine rupture during a trial of labor served as controls.Results. Twenty-five patients suffered a uterine rupture. The incidence of prior preterm cesarean delivery (PPCD) in this group was 40%, compared to 10.9% of 691 laboring vaginal birth after cesarean (VBAC) patients without rupture (p < 0.001). Patients in the rupture group with a PPCD were less likely to have experienced labor in the index pregnancy and more likely to have had an interdelivery interval of less than two years.Conclusions. An undeveloped lower segment in the preterm uterus represents a risk for later rupture, even if the incision is transverse.

Increased intrauterine frequency of Ureaplasma urealyticum in women with preterm labor and preterm premature rupture of the membranes and subsequent cesarean delivery

The purpose of this study was to evaluate the prevalence of microbial invasion of the amniotic cavity at the time of preterm cesarean delivery for therapy-resistant preterm labor or preterm premature rupture of membranes, which are events that commonly are induced by infection, and to compare this group of patients with a group of patients who underwent preterm cesarean delivery for indications other than preterm labor or preterm premature rupture of membranes. We studied 207 consecutive women between 23 and 34 weeks of gestation who underwent cesarean delivery. These patients were divided into 3 groups according to the indication for cesarean delivery: patients with preterm labor (group 1), patients with preterm premature rupture of membranes (group 2), and patients with other indications (group 3). In the course of the surgical procedure, amniotic fluid, amniotic membrane, and placental tissue specimens were collected for the detection of pathogens. Ureaplasma urealyticum was detected in 43.9% (58/132) of the patients of groups 1 and 2, with no significant difference between these 2 subgroups. In group 3, which served as the comparison group, Ureaplasma urealyticum was isolated in only 2.7% (2/75) of the patients. Ureaplasma urealyticum as a single pathogen was more frequent than all obligate pathogens together (43.9% vs 39.3%). Our results provide evidence for an association between intrauterine colonization with Ureaplasma urealyticum and both therapy-resistant preterm labor and preterm premature rupture of membranes.

Spinal Anesthesia-Induced Hypotension: A Risk Comparison Between Patients with Severe Preeclampsia and Healthy Women Undergoing Preterm Cesarean Delivery

We previously showed that, in comparison with term healthy parturients, patients with severe preeclampsia had a less frequent incidence of spinal hypotension, which was less severe and required less ephedrine. In the present study, we hypothesized that these findings were attributable to preeclampsia-associated factors rather than to a smaller uterine mass. The incidence and severity of hypotension were compared between severe preeclamptics (n = 65) and parturients with preterm pregnancies (n = 71), undergoing spinal anesthesia for cesarean delivery (0.5% bupivacaine, sufentanil, morphine). Hypotension was defined as the need for ephedrine (systolic blood pressure <100 mm Hg in parturients with preterm fetuses or 30% decrease in mean blood pressure in both groups). Apgar scores and umbilical arterial blood pH were also studied. Neonatal and placental weights were similar between the groups. Hypotension was less frequent in preeclamptic patients than in women with preterm pregnancies (24.6% versus 40.8%, respectively, P = 0.044). Although the magnitude of the decrease in systolic, diastolic, and mean arterial blood pressure was similar between groups, preeclamptic patients required less ephedrine than women in the preterm group to restore blood pressure to baseline levels (9.8 +/- 4.6 mg versus 15.8 +/- 6.2 mg, respectively, P = 0.031). The risk of hypotension in the preeclamptic group was almost 2 times less than that in the preterm group (relative risk = 0.603; 95% confidence interval, 0.362-1.003; P = 0.044). The impact of Apgar scores was minor, and umbilical arterial blood pH was not affected. We conclude that preeclampsia-associated factors, rather than a smaller uterine mass, account for the infrequent incidence of spinal hypotension in preeclamptic patients.

The Effect Of Pre-Pregnancy Body Mass Index, Gestational Weight Gain On Pregnancy Outcomes

Background: Nutritional status of women has been considered an important prognostic indicator of pregnancy outcomes. The study aims to show the effect of various pregnancy body mass index categories and corresponding gestational weight gain on pregnancy outcomes. Materials and Methods: 270 women were included in the study. BMI was categorized and weight gain was divided into two groups normal and abnormal based on IOM's recommendation. Chi square and one way ANOVA were used in the univarate analysis of the association between weight gain and corresponding adverse outcome (cesarean, preterm labor, low birth weight). Adjusted odds ratios for adverse outcomes were determined by multiple logistic regression models, while controlling for the following factors: maternal, age, parity, education. Results: For women with pre-pregnancy BMI<19, mean birth weight of newborn was significant low. (P<0.05) The abnormal weight gain during pregnancy wasn't related to an increased risk of preterm labor or cesarean delivery but it was highly associated with LBW. (P<0.05) Conclusion: Efforts should be made to attain appropriate weight gain to reduce the likelihood of low birth weight. Hence, special attention should be paid to women with low pre-pregnancy BMI.

The Influence of Hospital Closures in Nova Scotia on Perinatal Outcomes

Objective: To evaluate the effect of hospital closures on critical obstetrical interventions and perinatal outcomes in rural communities in Nova Scotia, Canada.Methods: A population-based cohort study was carried out for the years 1988 to 2002, using data extracted from the Nova Scotia Atlee Perinatal Database. Regions of maternal residence were defined geographically and administratively as Eastern, Northern, Western, and Central. The time periods of 1988 to 1993 and 1996 to 2002 were chosen based on the timing of hospital closures. Changes in rates of several perinatal outcomes were examined by region in relation to the extent of hospital closures experienced by that region.Results: The majority of hospital closures occurred in 1994 to 1995 with the establishment of new health regions, and affected the Western region most profoundly. In comparison with the Central region (relative risk [RR], 0.56; 95% confidence interval [Cl], 0.53–0.59), the temporal reduction in the rate of forceps-assisted vaginal delivery was smaller in the Western region (RR, 0.83; 95% Cl, 0.76–0.91; P < .001 ), but greater in the Northern (RR, 0.36; 95% Cl, 0.32–0.41; P < .001) and Eastern (RR, 0.26; 95% Cl, 0.23-0.30; P < .00 1) regions. The temporal increase in the rate of breastfeeding at discharge from hospital was smaller in the Northern region (RR, 1.36; 95% Cl, 1.29–1.45; P < .001) compared to that in the Central region (RR, 1.55; 95% Cl, 1.49–1.61 ). The decrease in the rate of fetal growth restriction was smaller in the Western (RR, 0.95; 95% Cl, 0.87-1.02; P = .002) and Eastern (RR, 0.90; 95% Cl, 0.82–0.98; P = .002) regions of residence compared to the Central region (RR, 0.75; 95% Cl, 0.71–0.79). There were no significant regional differences in temporal patterns of preterm induction and/or preterm Caesarean delivery, or perinatal mortality.Conclusion: Although trends over time demonstrated sorne regional differences in obstetrical interventions and perinatal outcomes, our retrospective evaluation did not reveal a consistent relationship between reductions in maternity services associated with hospital closures and systematic, population-level adverse perinatal consequences in Nova Scotia.

Trends in twin neonatal mortality rates in the United States, 1989 through 1999: influence of birth registration and obstetric intervention

Objective We sought to evaluate the contributions of changes in birth registration, labor induction, and cesarean delivery on trends in twin neonatal mortality rates. Study design We conducted a population-based, retrospective cohort study of twin live births, using linked birth-infant death data in the United States (1989-1999). Relative risks and 95% confidence intervals that quantified changes in neonatal (0-27 days) mortality rates were derived from ecologic logistic regression models that were fit after aggregation of the data by each state in the United States. Results The frequency of live born twins who weighed <500 g increased 72%, from 0.7% in 1989 to 1.2% in 1999, of live born twins who weighed 500 to 749 g and 750 to 999 g increased by 55% and 28%, respectively, between 1989 and 1999. Preterm birth rates increased by 19%, from 46.2% in 1989 to 57.2% in 1999. The rate of labor induction increased from 5.8% to 13.9%, and the cesarean delivery rate increased from 49.8% to 56.3%. Between 1989 to 1991 and 1997 to 1999, the crude neonatal mortality rates among twins who weighed ≥500 g declined by 37% (95% CI, 35%-40%) from 21.5 to 13.6 per 1000 twin live births. Adjustments for preterm labor induction, preterm cesarean delivery, term labor induction, term cesarean delivery, and sociodemographic factors had little influence on neonatal mortality rate trends. Conclusion Increases in preterm birth because of obstetric intervention among twins have not led to increases in twin neonatal mortality rates in the United States.

Cyclooxygenase isoforms and prostaglandin E 2 receptors in the ductus arteriosus

Background: A patent ductus arteriosus (DA) promotes fetal development. However, the DA must close immediately after birth. Prostaglandin E 2 (PGE 2) is the most important factor in the regulation of DA tone during fetal development. This eicosanoid is generated through the activities of cyclooxygenases-1 (COX-1) and -2 (COX-2) and mediates its effects by interacting with G protein-coupled E-prostanoid (EP) receptors EP 1, EP 2, EP 3, and EP 4. Objective: This article summarizes the role of COX-1 and -2 and PGE 2 receptors in fetal and neonatal DA tone. Methods: A MEDLINE search was performed of the English-language literature, using the terms ductus arteriosus, PGE 2, and lamb. Results: The DA is less responsive to PGE 2 in neonates than in fetuses. EP receptor subtypes 2 to 4 are expressed equivalently in fetal DA. Stimulation of all 3 receptor subtypes relaxes the DA. In the DA of newborns delivered at full term, EP 2 remains unchanged, EP 4 decreases, and changes in EP 3 expression are equivocal. The DA is less responsive to PGE 2 in newborns than in fetuses. The EP 4 receptor may represent a possible therapeutic target for regulating DA tone in premature newborns. An EP 2 agonist might be useful for maintaining DA patency in neonates and children with certain congenital heart diseases. Conclusions: COX-1 is the predominant isoenzyme in fetal DA, whereas COX-2 is upregulated in the DA immediately following birth. More research on patent DA and the role of preterm labor versus cesarean delivery is needed, as well as comparisons of the efficacy of selective EP-receptor targeting and enzymatic inhibition of COX and PGE 2 synthetases.

Trends in fetal growth among singleton gestations in the United States and Canada, 1985 through 1998

We examined trends in fetal growth among singleton live births in the United States and Canada. The data files (n = 48,637,680; 16.6% blacks) for US births, and the Canadian Birth Database of Statistics Canada (n = 3,167,702) for Canadian births were used. Trends were assessed between 1985-86 and 1997-98 with reference to mean birthweight, birthweight-for-gestational-age z-score, and proportions delivered low birthweight (< 2,500 g), small for gestational age (SGA: birthweight < 10th centile for gestational age) and large for gestational age (LGA: birthweight > 90th centile). The term "mean birth weight" increased in the US and Canada between 1985 and 1998, as have the mean z-score. Rates of term SGA births declined among US (11% among whites and 12% among blacks) and Canadian births (27%). Preterm SGA births increased by 3% and 17%, respectively, among US whites and blacks, but declined by 11% among Canadian births. Further, term LGA births increased in the US (5% among whites and 9% among blacks) and Canada (24%). Preterm LGA births declined by 13%, 25%, and 14% among US whites and blacks, and Canadian births, respectively. These findings suggest that US and Canadian babies are getting bigger. The role of preterm obstetrical induction and preterm cesarean delivery are likely to have influenced these trends.