Prevention of recurrent preterm delivery by 17 alpha-hydroxyprogesterone caproate

Expectant management compared with physical examination-indicated cerclage (EM-PEC) in selected women with a dilated cervix at 14(0/7)-25(6/7) weeks: results from the EM-PEC international cohort study

OBJECTIVE

The objective of the study was to compare pregnancy outcomes in selected women with a dilated cervix who underwent expectant management or physical examination-indicated cerclage.

STUDY DESIGN

This was a historical cohort study conducted by the Global Network for Perinatal and Reproductive Health. Women between 14(0/7) and 25(6/7) weeks' gestation with a dilated cervix were identified at 10 centers by ultrasound or digital examination. Primary outcome was time from presentation until delivery (weeks). Secondary outcomes were neonatal survival, birthweight greater than 1500 g and preterm birth less than 28 weeks. Multivariate regression was used to assess the likelihood of neonatal outcomes and control for confounders.

RESULTS

Of 225 women, 152 received a physical examination-indicated cerclage, and 73 were managed expectantly without cerclage. Cervical dilation, gestational age at presentation, and antenatal steroid use differed between groups. In the adjusted analyses, cerclage was associated with longer interval from presentation until delivery, improved neonatal survival, birthweight greater than 1500 g and preterm birth less than 28 weeks, compared with expectant management. Similar results were obtained in the analyses limited to women dilated between 2 and 4 cm (n = 122).

CONCLUSION

In this study, the largest cohort reported to date, physical examination-indicated cerclage appears to prolong gestation and improve neonatal survival, compared with expectant management in selected women with cervical dilation between 14(0/7) and 25(6/7) weeks. A randomized, controlled trial should be conducted to determine whether these potential benefits outweigh the risks of cerclage placement in this population.

Evaluation of fetal and maternal genetic variation in the progesterone receptor gene for contributions to preterm birth

Progesterone plays a critical role in the maintenance of pregnancy and has been effectively used to prevent recurrences of preterm labor. We investigated the role of genetic variation in the progesterone receptor (PGR) gene in modulating risks for preterm labor by examining both maternal and fetal effects. Cases were infants delivered prematurely at the University of Iowa. DNA was collected from the mother, infant, and father. Seventeen single nucleotide polymorphisms (SNP) and an insertion deletion variant in PGR were studied in 415 families. Results were then analyzed using transmission disequilibrium tests and log-linear-model-based analysis. DNA sequencing of the PGR gene was also carried out in 92 mothers of preterm infants. We identified significant associations between SNP in the PGR for both mother and preterm infant. No etiologic sequence variants were found in the coding sequence of the PGR gene. This study suggests that genetic variation in the PGR gene of either the mother or the fetus may trigger preterm labor.

Pharmacological prevention of prematurity

The acute treatment of premature labour is successful for delaying delivery for short periods of time. Acute tocolysis does not have a significant impact on perinatal outcome. This is likely to be because the process leading to labour occurs over a longer timeframe and therefore therapies instigated as preventative measures are more likely to be successful in delaying delivery. Identification of women at risk of preterm birth is essential to ensure therapies are targeted appropriately. Risk assessments for prediction include previous obstetric history, previous episode of threatened preterm labour, fetal fibronectin status and cervical length. Several groups of pharmacological agents have been studied for the prophylactic treatment of preterm labour. There is no evidence to support the use of tocolytics such as beta-mimetics and oxytocin receptor antagonists. Current studies of calcium channel blockers are too small to draw final conclusions. Non-steroidal anti-inflammatory drugs are associated with side effects on the fetal renal system and ductus arteriosus, making them suitable only for long term use in pregnancy with close ultrasound surveillance. Antibiotics used early in pregnancy in women with abnormal vaginal flora may reduce the risk of preterm birth; however, in women with other risk factors for preterm birth, metronidazole may be associated with an increased risk. The use of progesterone in women with a history of very early preterm labour is likely to be beneficial for preventing preterm labour.

Progesterone vaginal gel for the reduction of recurrent preterm birth: primary results from a randomized, double-blind, placebo-controlled trial

OBJECTIVE

Preterm birth is the leading cause of perinatal morbidity and mortality worldwide. Treatment of preterm labor with tocolysis has not been successful in improving infant outcome. The administration of progesterone and related compounds has been proposed as a strategy to prevent preterm birth. The objective of this trial was to determine whether prophylactic administration of vaginal progesterone reduces the risk of preterm birth in women with a history of spontaneous preterm birth.

METHODS

This randomized, double-blind, placebo- controlled, multinational trial enrolled and randomized 659 pregnant women with a history of spontaneous preterm birth. Between 18 + 0 and 22 + 6 weeks of gestation, patients were assigned randomly to once-daily treatment with either progesterone vaginal gel or placebo until either delivery, 37 weeks' gestation or development of preterm rupture of membranes. The primary outcome was preterm birth at </= 32 weeks of gestation. The trial was analyzed using an intent-to-treat strategy.

RESULTS

Baseline characteristics were similar in the two treatment groups. Progesterone did not decrease the frequency of preterm birth at </= 32 weeks. There was no difference between the groups with respect to the mean gestational age at delivery, infant morbidity or mortality or other maternal or neonatal outcome measures. Adverse events during the course of treatment were similar for the two groups.

CONCLUSION

Prophylactic treatment with vaginal progesterone did not reduce the frequency of recurrent preterm birth (</= 32 weeks) in women with a history of spontaneous preterm birth. The effect of progesterone administration in patients at high risk for preterm delivery as determined by methods other than history alone (e.g. sonographic cervical length) requires further investigation.

Follow-up of Children Exposed In Utero to 17 α-Hydroxyprogesterone Caproate Compared With Placebo

OBJECTIVE

To assess whether there are evident adverse effects of 17 alpha-hydroxyprogesterone caproate after in utero exposure.

METHODS

This study evaluated surviving children of mothers who participated in a multicenter placebo-controlled trial of weekly intramuscular 17 alpha-hydroxyprogesterone caproate, with a 2:1 allocation to 17 alpha-hydroxyprogesterone caproate and placebo, respectively. The guardian was interviewed about the child's general health. Children underwent a physical examination and developmental screen with the Ages and Stages Questionnaire. Gender-specific roles were assessed with the Preschool Activities Inventory.

RESULTS

Of 348 eligible surviving children, 278 (80%) were available for evaluation (194 in the 17 alpha-hydroxyprogesterone caproate group and 84 in the placebo group). The mean age at follow-up was 48 months. No significant differences were seen in health status or physical examination, including genital anomalies, between 17 alpha-hydroxyprogesterone caproate and placebo children. Scores for gender-specific roles (Preschool Activities Inventory) were within the normal range and similar between 17 alpha-hydroxyprogesterone caproate and placebo groups.

CONCLUSION

17 alpha-hydroxyprogesterone caproate seems to be safe for the fetus when administered in the second and third trimesters.

Vaginal progesterone is associated with a decrease in risk for early preterm birth and improved neonatal outcome in women with a short cervix: a secondary analysis from a randomized, double-blind, placebo-controlled trial

OBJECTIVE

To investigate the efficacy of vaginal progesterone to prevent early preterm birth in women with sonographic evidence of a short cervical length in the midtrimester.

METHODS

This was a planned, but modified, secondary analysis of our multinational, multicenter, randomized, placebo-controlled trial, in which women were randomized between 18 + 0 and 22 + 6 weeks of gestation to receive daily treatment with 90 mg of vaginal progesterone gel or placebo. Cervical length was measured with transvaginal ultrasound at enrollment and at 28 weeks of gestation. Treatment continued until either delivery, 37 weeks of gestation or development of preterm rupture of membranes. Maternal and neonatal outcomes were evaluated for the subset of all randomized women with cervical length < 28 mm at enrollment. The primary outcome was preterm birth at </= 32 weeks.

RESULTS

A cervical length < 28 mm was identified in 46 randomized women: 19 of 313 who received progesterone and 27 of 307 who received the placebo. Baseline characteristics of the two groups were similar. In women with a cervical length < 28 mm, the rate of preterm birth at </= 32 weeks was significantly lower for those receiving progesterone than it was for those receiving the placebo (0% vs. 29.6%, P = 0.014). With progesterone, there were fewer admissions into the neonatal intensive care unit (NICU; 15.8% vs. 51.9%, P = 0.016) and shorter NICU stays (1.1 vs. 16.5 days, P = 0.013). There was also a trend toward a decreased rate of neonatal respiratory distress syndrome (5.3% vs. 29.6%, P = 0.060).

CONCLUSION

Vaginal progesterone may reduce the rate of early preterm birth and improve neonatal outcome in women with a short sonographic cervical length.

Are women who have had a preterm twin delivery at greater risk of preterm birth in a subsequent singleton pregnancy?

OBJECTIVE

The purpose of this study was to determine whether preterm birth of twins is associated with an increased risk of preterm birth in a subsequent singleton pregnancy.

STUDY DESIGN

All patients who delivered a twin gestation and a subsequent singleton pregnancy at Northwestern Memorial Hospital during a 10-year period were identified. We used a cohort study design, comparing the outcomes of the singleton pregnancies in women with preterm twin deliveries to those pregnancies with term twin deliveries.

RESULTS

One hundred sixty-seven women delivered twins followed by a singleton pregnancy. Women whose twin delivery was preterm (n = 99) were more likely than those who had delivered a term twin pregnancy (n = 68) to deliver a subsequent preterm singleton pregnancy (13.1% vs 2.9%; odds ratio, 5.0; 95% CI, 1.1, 22.9).

CONCLUSION

Preterm birth of twins is associated with an increased risk of preterm delivery in a subsequent singleton pregnancy.

Clinical characteristics of women prescribed 17 alpha-hydroxyprogesterone caproate in the community setting

OBJECTIVE

The objective of the study was to describe clinical characteristics and pregnancy outcomes of women in a community setting prescribed 17 alpha-hydroxyprogesterone caproate (17P) prophylaxis for prevention of preterm delivery (PTD).

STUDY DESIGN

A retrospective review was conducted of data collected from patients enrolled for weekly outpatient 17P administration and nursing assessment between April 2004 and January 1, 2006 (n = 1979). Pregnancy history, referral indication, labor/delivery onset (spontaneous or indicated), and gestational duration were identified.

RESULTS

Almost 80% of women prescribed 17P had a prior preterm delivery, although only 711 of the study population (35.9%) met National Institute of Child Health and Human Development (NICHD) study criteria for 17P including initiation of treatment at 16 to 20.9 weeks. Spontaneous PTD occurred in 37.3%; 22.1% delivered less than 35 weeks; and 9.0% less than 32 weeks. More than one quarter of patients (26.9%) discontinued 17P at less than 34 weeks and prior to delivery.

CONCLUSION

In community practice, only one third of patients receiving 17P met strict NICHD study criteria. Early initiation and adherence to completion of therapy are clinical issues related to 17P prophylaxis.

Increased incidence of gestational diabetes in women receiving prophylactic 17alpha-hydroxyprogesterone caproate for prevention of recurrent preterm delivery

OBJECTIVE

Progesterone has a known diabetogenic effect. We sought to determine whether the incidence of gestational diabetes mellitus (GDM) is altered in women receiving weekly 17alpha-hydroxyprogesterone caproate (17P) prophylaxis for the prevention of recurrent preterm birth.

RESEARCH DESIGN AND METHODS

Singleton gestations in women having a history of preterm delivery were identified from a database containing prospectively collected information from women receiving outpatient nursing services related to a high-risk pregnancy. Included were patients enrolled for outpatient management at <27 weeks' gestation with documented pregnancy outcome and delivery at >28 weeks. Patients with preexisting diabetes were excluded. The incidence of GDM was compared between patients who received prophylactic intramuscular 17P (250-mg weekly injection initiated between 16.0 and 20.9 weeks' gestation) and those who did not.

RESULTS

Maternal BMI and age were similar. The incidence of GDM was 12.9% in the 17P group (n = 557) compared with 4.9% in control subjects (n = 1,524, P < 0.001; odds ratio 2.9 [95% CI 2.1-4.1]).

CONCLUSIONS

The use of 17P for the prevention of recurrent preterm delivery is associated with an increased risk of developing GDM. Early GDM screening is appropriate for women receiving 17P prophylaxis.

Prophylaxis with 17 alpha-hydroxyprogesterone caproate for prevention of recurrent preterm delivery: does gestational age at initiation of treatment matter?

OBJECTIVE

The purpose of this study was to determine effectiveness of 17 alpha-hydroxyprogesterone caproate (17 P) prophylaxis by gestational age (GA) at 17 P initiation.

STUDY DESIGN

Singleton gestations with > or = 1 preterm birth (PTB) treated with 17 P prophylaxis for recurrent preterm birth before 27 weeks were identified from a data base. Data were stratified by GA at 17 P initiation (16-20.9 [n = 599] weeks and 21-26.9 [n = 307] weeks) and number of PTB (1, 2, > 2). Outcome variables were PTB at < 37, < 35, and < 32 weeks.

RESULTS

No significant differences were found in gestational age at delivery or rates of recurrent PTB < 37, < 35, and < 32 weeks between those women initiating 17 P at 16-20.9 weeks or 21-26.9 weeks, or when stratified by number of prior preterm deliveries.

CONCLUSION

Initiation of 17 P prophylaxis at 21-26.9 weeks is as effective as initiation at 16-20.9 weeks of gestation.

A short interpregnancy interval is a risk factor for preterm birth and its recurrence

OBJECTIVE

We tested the hypothesis that short interpregnancy intervals (IPIs) increase the risk for preterm birth (PTB), recurrence of PTB, and delivery at early extremes of gestational age.

STUDY DESIGN

Using the Missouri Department of Health's birth certificate database, we performed a population-based cohort study of 156,330 women who had 2 births from 1989-1997. The association between IPI and subsequent pregnancy outcome was assessed.

RESULTS

The shortest IPIs (<6 months) increased the risk of extreme PTB (adjusted odds ratio, 1.41; 95% CI, 1.13-1.76). IPIs of <6 months and 6-12 months increased the overall risk of PTB (adjusted odds ratios, 1.48 [95% CI, 1.37-1.61] and 1.14 [95% CI, 1.06-1.23], respectively) and PTB recurrence (adjusted odds ratios, 1.44 [95% CI, 1.19-1.75] and 1.24 [95% CI, 1.02-1.50], respectively).

CONCLUSION

The risk of PTB and its recurrence increases with short IPIs, even after adjustment for coexisting risk factors. This highlights the importance of counseling women with either an initial term or preterm birth to wait at least 12 months between delivery and subsequent conception.

Interpregnancy primary care and social support for African-American women at risk for recurrent very-low-birthweight delivery: a pilot evaluation

OBJECTIVES

Very-low-birthweight (VLBW) delivery accounts for the majority of neonatal mortality and the black-white disparity in infant mortality. The risk of recurrent VLBW is highest for African-Americans of lower socioeconomic status. This study explores whether the provision of primary health care and social support following a VLBW delivery improves subsequent child spacing and pregnancy outcomes for low-income, African-American women.

METHODS

This pilot study of mixed prospective-retrospective cohort design enrolled African-American women who qualified for indigent care and delivered a VLBW infant at a public hospital in Atlanta from November 2003 through March 2004 into the intervention cohort (n (1) = 29). The intervention consisted of coordinated primary health care and social support for 24 months following the VLBW delivery. A retrospective cohort was assembled from consecutive women meeting the same eligibility criteria who delivered a VLBW infant during July 2001 through June 2002 (n (2) = 58). The number of pregnancies conceived within 18 months of the index VLBW delivery and the number of adverse pregnancy outcomes for each cohort was compared with Poisson regression.

RESULTS

Women in the control cohort had, on average, 2.6 (95% CI: 1.1-5.8) times as many pregnancies within 18 months of the index VLBW delivery and 3.5 (95% CI: 1.0-11.7) times as many adverse pregnancy outcomes as women in the intervention cohort.

CONCLUSIONS

This small, pilot study suggests that primary health care and social support for low-income, African-American women following a VLBW delivery may enhance achievement of a subsequent 18-month interpregnancy interval and reduce adverse pregnancy outcomes.

Redirection of cytokine production by lymphocytes from women with pre-term delivery by dydrogesterone

PROBLEM

To study the ability of dydrogesterone to modulate the production of pro-inflammatory and anti-inflammatory cytokines by lymphocytes from women undergoing pre-term delivery (PTD).

METHOD OF STUDY

Peripheral blood mononuclear cells (PBMC) from 18 subjects undergoing PTD were stimulated with the mitogen phytohemagglutinin in the presence and absence of progesterone and dydrogesterone. The levels of interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, interleukin (IL)-4, and IL-10 in culture supernatants were then estimated by enzyme-linked immunoabsorbant assay. Cytokine production in the presence and absence of progesterone and dydrogesterone were compared.

RESULTS

The exposure of PBMC to dydrogesterone resulted in a significant inhibition in the production of the pro-inflammatory cytokines IFN-gamma and TNF-alpha and a significant increase in the levels of the anti-inflammatory cytokine IL-4, resulting in a substantial shift in the ratio of Th1/Th2 cytokines.

CONCLUSION

Dydrogesterone induces a shift in cytokine bias, by inhibiting pro-inflammatory cytokine production and increasing anti-inflammatory cytokine production.

Progesterone and the risk of preterm birth among women with a short cervix

BACKGROUND

Previous randomized trials have shown that progesterone administration in women who previously delivered prematurely reduces the risk of recurrent premature delivery. Asymptomatic women found at midgestation to have a short cervix are at greatly increased risk for spontaneous early preterm delivery, and it is unknown whether progesterone reduces this risk in such women.

METHODS

Cervical length was measured by transvaginal ultrasonography at a median of 22 weeks of gestation (range, 20 to 25) in 24,620 pregnant women seen for routine prenatal care. Cervical length was 15 mm or less in 413 of the women (1.7%), and 250 (60.5%) of these 413 women were randomly assigned to receive vaginal progesterone (200 mg each night) or placebo from 24 to 34 weeks of gestation. The primary outcome was spontaneous delivery before 34 weeks.

RESULTS

Spontaneous delivery before 34 weeks of gestation was less frequent in the progesterone group than in the placebo group (19.2% vs. 34.4%; relative risk, 0.56; 95% confidence interval [CI], 0.36 to 0.86). Progesterone was associated with a nonsignificant reduction in neonatal morbidity (8.1% vs. 13.8%; relative risk, 0.59; 95% CI, 0.26 to 1.25; P=0.17). There were no serious adverse events associated with the use of progesterone.

CONCLUSIONS

In women with a short cervix, treatment with progesterone reduces the rate of spontaneous early preterm delivery. (ClinicalTrials.gov number, NCT00422526 [ClinicalTrials.gov].).

A trial of 17 alpha-hydroxyprogesterone caproate to prevent prematurity in twins

BACKGROUND

In singleton gestations, 17 alpha-hydroxyprogesterone caproate (17P) has been shown to reduce the rate of recurrent preterm birth. This study was undertaken to evaluate whether 17P would reduce the rate of preterm birth in twin gestations.

METHODS

We performed a randomized, double-blind, placebo-controlled trial in 14 centers. Healthy women with twin gestations were assigned to weekly intramuscular injections of 250 mg of 17P or matching placebo, starting at 16 to 20 weeks of gestation and ending at 35 weeks. The primary study outcome was delivery or fetal death before 35 weeks of gestation.

RESULTS

Six hundred sixty-one women were randomly assigned to treatment. Baseline demographic data were similar in the two study groups. Six women were lost to follow-up; data from 655 were analyzed (325 in the 17P group and 330 in the placebo group). Delivery or fetal death before 35 weeks occurred in 41.5% of pregnancies in the 17P group and 37.3% of those in the placebo group (relative risk, 1.1; 95% confidence interval [CI], 0.9 to 1.3). The rate of the prespecified composite outcome of serious adverse fetal or neonatal events was 20.2% in the 17P group and 18.0% in the placebo group (relative risk, 1.1; 95% CI, 0.9 to 1.5). Side effects of the injections were frequent in both groups, occurring in 65.9% and 64.4% of subjects, respectively (P=0.69), but were generally mild and limited to the injection site.

CONCLUSIONS

Treatment with 17 alpha-hydroxyprogesterone caproate did not reduce the rate of preterm birth in women with twin gestations. (ClinicalTrials.gov number, NCT00099164 [ClinicalTrials.gov].).

Prediction and Prevention of Recurrent Spontaneous Preterm Birth

Rates of preterm birth have continued to rise despite intensive research efforts over the last several decades. A woman who has a spontaneous preterm birth is at high risk for a subsequent preterm birth. Studies have identified clinical, sonographic, and biochemical markers that help to identify the women at highest risk. Determining cervical length and measuring cervicovaginal fibronectin have been proposed as useful tools for evaluating women at risk of preterm birth and may identify those who might benefit from a timely course of antenatal corticosteroids, but effective interventions to prevent preterm birth remain elusive. In the prevention of recurrent spontaneous preterm birth, recent trials have confirmed the use of progesterone beginning in the second trimester as an effective intervention. Optimal management of women with a history of spontaneous preterm birth includes a thorough review of the obstetric, medical, and social history, with attention to potentially reversible causes of preterm birth (eg, smoking cessation, acute infections, strenuous activities), accurate ultrasound dating, consideration of progesterone therapy beginning at 16-20 weeks of gestation, and close surveillance during the pregnancy for evolving findings. Results from the ongoing trials of cerclage as an interventional therapy and omega-3 fatty acid supplementation as a preventive therapy will provide additional knowledge for the optimal management of these high-risk women.

Subgroup analysis in obstetrics clinical trials

Although clinical trials report results in the aggregate, clinicians often wish to tailor treatments that are based on demographic, historic, clinical, or laboratory characteristics of their patients and are interested therefore in trial results that are presented separately according to such characteristics. Unfortunately, such subgroup analysis often are done incorrectly and often are misinterpreted, even when done correctly. Only subgroups that are defined by characteristics that are determined at or before the moment of randomization are valid. It is incorrect to determine whether treatment is effective among a subgroup of patients according to the probability value in that particular subgroup. The correct method uses a formal test for interaction. However, even when done correctly, most subgroup differences in treatment effectiveness prove to be spurious. A priori definition of the subgroup, strong supporting rationale, and, ultimately, replication in other studies increase confidence that subgroup differences are valid.

Progesterone for the prevention of preterm birth in women with multiple pregnancies: the AMPHIA trial

Background

15% of multiple pregnancies ends in a preterm delivery, which can lead to mortality and severe long term neonatal morbidity. At present, no generally accepted strategy for the prevention of preterm birth in multiple pregnancies exists. Prophylactic administration of 17-alpha hydroxyprogesterone caproate (17OHPC) has proven to be effective in the prevention of preterm birth in women with singleton pregnancies with a previous preterm delivery. At present, there are no data on the effectiveness of progesterone in the prevention of preterm birth in multiple pregnancies.

Methods/Design

We aim to investigate the hypothesis that 17OHPC will reduce the incidence of the composite neonatal morbidity of neonates by reducing the early preterm birth rate in multiple pregnancies. Women with a multiple pregnancy at a gestational age between 15 and 20 weeks of gestation will be entered in a placebo-controlled, double blinded randomised study comparing weekly 250 mg 17OHPC intramuscular injections from 16–20 weeks up to 36 weeks of gestation versus placebo. At study entry, cervical length will be measured. The primary outcome is composite bad neonatal condition (perinatal death or severe morbidity). Secondary outcome measures are time to delivery, preterm birth rate before 32 and 37 weeks, days of admission in neonatal intensive care unit, maternal morbidity, maternal admission days for preterm labour and costs. We need to include 660 women to indicate a reduction in bad neonatal outcome from 15% to 8%. Analysis will be by intention to treat. We will also analyse whether the treatment effect is dependent on cervical length.

Discussion

This trial will provide evidence as to whether or not 17OHPC-treatment is an effective means of preventing bad neonatal outcome due to preterm birth in multiple pregnancies.

Trial registration

Current Controlled Trials ISRCTN40512715

Development and validation of a high-performance liquid chromatography-mass spectrometric assay for the determination of 17alpha-hydroxyprogesterone caproate (17-OHPC) in human plasma

A sensitive and specific method for the determination of 17alpha-hydroxyprogesterone caproate (17-OHPC) in human plasma using high-performance liquid chromatography and mass spectrometry has been developed and validated. Plasma samples were processed by a solid phase extraction (SPE) procedure using Oasis HLB extraction cartridge prior to chromatography. Medroxyprogesterone acetate (MPA) was used as the internal standard. Chromatography was performed using Waters C18 Symmetry analytical column, 3.5 microm, 2.1 mm x 10 mm, using a gradient elusion with a mobile phase consisting of acetonitrile [A] and 5% acetonitrile in water [B], with 0.1% formic acid being added to both [A] and [B], at a flow rate 0.2 ml/min. The retention times of 17-OHPC and MPA were 8.1 and 5.0 min, respectively, with a total run time of 15 min. Analysis was performed on Thermo Electron Finnigan TSQ Quantum Ultra mass spectrometer in a selected reaction-monitoring (SRM), positive mode using electron spray ionization (ESI) as an interface. Positive ions were measured using extracted ion chromatogram mode. The extracted ions following SRM transitions monitored were m/z 429.2-->313.13 and 429.2-->271.1, for 17-OHPC and m/z 385.1-->276 for MPA. The extraction recoveries at concentrations of 5, 10 and 50 ng/ml were 97.1, 92.6 and 88.7%, respectively. The assay was linear over the range 0.5-50 ng/ml for 17-OHPC. The analysis of standard samples for 17-OHPC 0.5, 1, 2.5, 5, 10, 25 and 50 ng/ml demonstrated a relative standard deviation of 16.7, 12.4, 13.7, 1.4, 5.2, 3.7 and 5.3%, respectively (n=6). This method is simple, adaptable to routine application, and allows easy and accurate measurement of 17-OHPC in human plasma.

Recurrent preterm birth

Recurrent preterm birth is frequently defined as two or more deliveries before 37 completed weeks of gestation. The recurrence rate varies as a function of the antecedent for preterm birth: spontaneous versus indicated. Spontaneous preterm birth is the result of either preterm labor with intact membranes or preterm prelabor rupture of the membranes. This article reviews the body of literature describing the risk of recurrence of spontaneous and indicated preterm birth. Also discussed are the factors which modify the risk for recurrent spontaneous preterm birth (a short sonographic cervical length and a positive cervicovaginal fetal fibronectin test). Patients with a history of an indicated preterm birth are at risk not only for recurrence of this subtype, but also for spontaneous preterm birth. Individuals of black origin have a higher rate of recurrent preterm birth.

Recurrence risk for preterm delivery

OBJECTIVE

To estimate recurrence risk of preterm delivery in third births.

STUDY DESIGN

We conducted a population-based cohort study of Missouri mothers who delivered 3 consecutive singleton live births during 1989-1997. The recurrence risk was computed for 4 cohorts based on prior preterm delivery status and adjusted using Mantel-Haenszel stratified analysis.

RESULTS

The study population included 19,025 third births. The recurrence risk ranged from 42% (for women with 2 prior preterm deliveries), through 21% (term/preterm) and 13% (preterm/term), to 5% (term/term). The recurrence risk was highest (57%) for women with 2 prior very preterm deliveries (21-31 weeks) and lowest (33%) for those with 2 prior moderate preterm deliveries (32-36 weeks). The recurrence risk was less pronounced for women with 1 prior very or moderate preterm delivery.

CONCLUSION

These data show a strong association between prior preterm delivery and recurrence risk, which is affected by the frequency, order, and severity of prior preterm births.

Steroid hormone control of myometrial contractility and parturition

The precise temporal control of uterine contractility is essential for the success of pregnancy. For most of pregnancy, progesterone acting through genomic and non-genomic mechanisms promotes myometrial relaxation. At parturition the relaxatory actions of progesterone are nullified and the combined stimulatory actions of estrogens and other factors such as myometrial distention and immune/inflammatory cytokines, transform the myometrium to a highly contractile and excitable state leading to labor and delivery. This review addresses current understanding of how progesterone and estrogens affect the contractility of the pregnancy myometrium and how their actions are coordinated and controlled as part of the parturition cascade.

Impact of progesterone on cytokine-stimulated nuclear factor-kappaB signaling in HeLa cells

OBJECTIVE

A key event in the pathways leading to preterm labor may be the activation of nuclear factor-kappaB (NF-kappaB) in the fetal membranes and the cervix. Anti-inflammatory agents, such as the corticosteroids, inhibit the activation of NF-kappaB. We proposed to investigate the effects of progesterone pretreatment on cytokine-stimulated activation of NF-kappaB in HeLa cells, a human cervical epithelial cell line.

METHODS

HeLa cells were pretreated with 10(-7) M progesterone for 24 hours and exposed to 1 ng/mL interleukin-1beta (IL-1beta) for 1 hour. Nuclear and cytosolic extracts were subjected to Western blot analysis using anti-p65 and anti-inhibitory protein-kappaBalpha (anti-IkappaBalpha) antibodies. Densitometric data (n=5) were compared using Kruskal-Wallis test.

RESULTS

Pretreatment with progesterone interfered with IL-1beta-induced IkappaBalpha degradation. However, progesterone pretreatment resulted in a significant decrease in NF-kappaB protein subunit p65 in the cytoplasm. Pretreatment with progesterone did not reduce the amount of nuclear p65 and did not interfere with nuclear translocation of p65.

CONCLUSION

Our observations suggest that any possible role played by progesterone in preterm labor prevention is not exerted through anti-inflammatory mechanisms of NF-kappaB down-regulation.

Preconception care between pregnancies: the content of internatal care

For more than two decades, prenatal care has been a cornerstone of our nation's strategy for improving pregnancy outcomes. In recent years, however, a growing recognition of the limits of prenatal care and the importance of maternal health before pregnancy has drawn increasing attention to preconception and internatal care. Internatal care refers to a package of healthcare and ancillary services provided to a woman and her family from the birth of one child to the birth of her next child. For healthy mothers, internatal care offers an opportunity for wellness promotion between pregnancies. For high-risk mothers, internatal care provides strategies for risk reduction before their next pregnancy. In this paper we begin to define the contents of internatal care. The core components of internatal care consist of risk assessment, health promotion, clinical and psychosocial interventions. We identified several priority areas, such as FINDS (family violence, infections, nutrition, depression, and stress) for risk assessment or BBEEFF (breastfeeding, back-to-sleep, exercise, exposures, family planning and folate) for health promotion. Women with chronic health conditions such as hypertension, diabetes, or weight problems should receive on-going care per clinical guidelines for their evaluation, treatment, and follow-up during the internatal period. For women with prior adverse outcomes such as preterm delivery, we propose an internatal care model based on known etiologic pathways, with the goal of preventing recurrence by addressing these biobehavioral pathways prior to the next pregnancy. We suggest enhancing service integration for women and families, including possibly care coordination and home visitation for selected high-risk women. The primary aim of this paper is to start a dialogue on the content of internatal care.

Born too soon: the continuing challenge of preterm labor and birth in the United States

Prematurity is the single greatest cause of morbidity and mortality in obstetrics. Families, health care services, and education systems experience the impact of prematurity for the lifetime of the preterm-born child. Health care providers have tried to lower the preterm birth rate with prevention both before and during pregnancy and intervention for symptomatic women. The inability of the health care system to significantly decrease the incidence of preterm birth continues to be a challenge. To further complicate the situation, new data shows that infants born between 34 and 37 weeks' gestation who were thought to have minimal long-term effects of preterm birth may be more at risk than previously appreciated. This article reviews evidence-based risk identification, prevention, and management of women experiencing preterm labor and birth.

Cervical length changes during preterm cervical ripening: effects of 17-alpha-hydroxyprogesterone caproate

OBJECTIVE

The purpose of this study was to evaluate whether 17-alpha-hydroxyprogesterone caproate (17P) treatment affect changes in cervical length.

STUDY DESIGN

Women with singleton pregnancy, between 25 and 33 + 6 weeks of gestation, who were hospitalized for preterm labor were included. Patients with rupture of membranes and/or signs of chorioamnionitis were excluded. Sixty undelivered patients were allocated randomly to either observation or to receive 341 mg of 17P intramuscularly, twice each week until gestational week 36. Cervical length was measured by transvaginal ultrasound scanning at discharge and at day 7 and 21 after discharge. Statistical comparisons were done with analysis of variance and chi-square test.

RESULTS

Shortening of the cervix in the observation group (30 cases) was higher than in the 17P group (30 cases) both at day 7 (2.37 +/- 2.0 mm vs 0.83 +/- 1.74 mm; P = .002) and day 21 (4.60 +/- 2.73 mm vs 2.40 +/- 2.46 mm; P = .002). Treatment with 17P was associated with both a reduction in the risk of cervical shortening of > or = 4 mm (odds ratio, 0.18; 95% CI, 0.04-0.66) and in the risk of preterm delivery (odds ratio, 0.15; 95% CI, 0.04-0.58).

CONCLUSION

Undelivered patients after preterm labor undergo progressive shortening of the cervix, which is attenuated by 17P treatment.

Predicting preterm delivery in asymptomatic patients with prior preterm delivery by measurement of cervical length and phosphorylated insulin-like growth factor-binding protein-1

OBJECTIVE

To evaluate the efficacy of cervical length measurement in combination with a bedside assessment of phosphorylated insulin-like growth factor-binding protein-1 (phIGFBP-1) as a predictor of preterm delivery in asymptomatic pregnant women with a history of preterm birth.

METHODS

Cervical length was measured using transvaginal sonography at 22-24 weeks of gestation in 105 singleton pregnancies and a rapid strip test was performed to detect phIGFBP-1 in cervical secretions from 24 to 34 weeks. Receiver-operating characteristics (ROC) curves were constructed to compare the performance of phIGFBP-1 at different gestational ages, and cervical length at 22-24 weeks, in predicting preterm delivery.

RESULTS

The rate of spontaneous delivery before 37 and 34 weeks was 23.8% and 11.4%, respectively. Women with cervical lengths less than 20 mm had a risk of spontaneous preterm delivery before 34 and 37 weeks of 43.5% and 69.6%, respectively. The performance of phIGFBP-1 levels as a predictor of preterm delivery was significantly higher when the test was carried out at 30 weeks' gestation. Cervical assessment in combination with phIGFBP-1 at 30 weeks had the steepest ROC curve (area under the curve=0.93; 95% CI, 0.88-0.98, P<0.001).

CONCLUSION

Both cervical length and phIGFBP-1 measurement are useful in the prediction of preterm delivery in patients with a history of preterm birth and the combined method of measuring cervical length at 22-24 weeks and phIGFBP-1 at 30 weeks improves upon either method used alone.

Setting up a preterm prevention clinic: a practical guide

In gynaecology, specialist menopause, urogynae, colposcopy, infertility, pelvic pain and cancer, rapid access clinics exist at many teaching and busy district general hospitals in the UK. Similarly, in obstetrics many busy maternity units have fetal medicine clinics, dedicated twins clinics and maternal medicine clinics, incorporating various general medical conditions and conditions peculiarly appropriate to pregnancy such as haematological disorders, diabetes and epilepsy. In contrast, in very few hospitals is there a dedicated clinic for women at increased risk of preterm birth, yet this is the major cause of neonatal mortality and morbidity in the developed world. Such a situation may be due to the confusion created by the fact that preterm birth is a heterogeneous condition with multiple aetiologies and hence multiple therapeutic interventions. It is possible to identify a group of women at particularly high risk of preterm birth in whom screening and interventional techniques have the potential to reduce the mortality and morbidity associated with spontaneous preterm labour and preterm birth.

Early second-trimester inflammatory markers and short cervical length and the risk of recurrent preterm birth

This study aimed to analyze the associations between serum and cervicovaginal inflammatory markers and recurrent spontaneous preterm birth in a cohort study of 62 pregnant women with > or =1 prior early spontaneous birth. Serum samples and cervicovaginal swabs from the women were obtained at enrollment in early second trimester (week 12-25). Cervical length was measured by ultrasound and dicotomized in to short (< or =25 mm) and long cervices (>25 mm). The study endpoints were spontaneous preterm birth before 35 weeks and secondarily<37 weeks. Multiple inflammatory markers in serum (IL-1beta, IL-2, IL-5, IL-6, IL-8, IL-12, IL-18, TNF-alpha, TGF-beta, sTNF-R1, GM-CSF and TREM-1) and cervicovaginal secretions (IL-18, sTNF-RI and sIL-6) were individually associated with spontaneous preterm birth. Short cervical length did not explain associations between inflammatory markers and spontaneous preterm birth. Serum and cervicovaginal inflammatory markers did not correlate. In a combined prediction model using both serum and vaginal inflammatory markers, serum TNF-alpha, cervicovaginal sIL-6Ralpha and cervical length predicted 69% of all recurrent spontaneous preterm birth at a 5% false-positive rate. In conclusion, cervical length, serum TNF-alpha and cervicovaginal sIL-6Ralpha provide a clinically useful prediction of recurrent preterm birth in early second-trimester in women with a prior spontaneous preterm birth.

Spontaneous preterm delivery and gestational diabetes: the impact of glycemic control

OBJECTIVE

Opinions differ whether the rate of spontaneous preterm delivery (sPTD) increases in pregnancies complicated with GDM. We sought to characterize, which factors may influence the rate of sPTD in GDM.

METHODS

We conducted a retrospective study with 1,526 GDM patients, all treated at the same center by the same diabetic protocol using self-blood glucose monitoring. The rate of sPTD was compared to that of 10,560 non-diabetic women. Eligibility for the study was limited to women with a singleton pregnancy with spontaneous onset of delivery before 37 weeks of gestation with no history of chronic maternal illness, i.e., chronic hypertension or development of preeclampsia in the current pregnancy, and no clear indication for preterm delivery. Mean blood glucose < 105 mg dl(-1) was defined as well controlled.

RESULTS

Overall, no difference was found in the rate of sPTD in GDM (163/1,526, 10.7%) in comparison to non-GDM patients (1193/10,560, 11.3%, P = 0.2). In the GDM group, a comparison between women with and without sPTD found no difference in maternal age (28.1 +/- 6 vs. 28.2 +/- 6), prepregnancy BMI (28.1 +/- 5 vs. 27.8 +/- 6), rate of nulliparity (38 vs. 34%) or ethnicity origin. GDM patients with sPTD were characterized by higher glucose values in the OGTT and higher mean blood glucose (114 +/- 16 vs. 106 +/- 14, P < 0.0001). Sixty-five percent of patients with sPTD versus. 46% in the non-sPTD were in poor glycemic control (P = 0.004). Multiple logistic regressions, when the dependent variable was sPTD revealed that mean blood glucose (OR 1.94 95% CI 1.25-3.0), history of sPTD (OR 3.25 95% CI 2.1-4.8) and parity (OR 1.49 95% CI 1.05-2.2) were contributing factors.

CONCLUSION

The rate of sPTD in GDM is not increased in comparison to non-GDM patients, but reaching established levels of glycemic control may reduce the rate of sPTD in GDM.

Emerging drug therapies for preventing spontaneous preterm labor and preterm birth

Preterm birth (PTB) is the main cause of neonatal mortality and morbidity in the developed world. Historically, the approach for the prevention of PTB has been reactive rather than proactive. With the introduction of new screening tests and a greater emphasis on prevention rather than treatment, a number of new approaches have been introduced that show promise. Progesterone, which is responsible for myometrial quiescence in pregnancy and is used in women with a previous history of PTB, is associated with a significant reduction in the incidence of PTB and low birth weight. Infection is an important cause of PTB in < or = 40% of women. The appropriate antibiotics administered early in pregnancy to women with abnormal genital tract flora have been associated with a 40-60% reduction in the incidence of PTB. Although there has been debate regarding the benefits of nutritional supplementation for the prevention of many complications of pregnancy, recent evidence suggests that fish oil supplementation can be shown to reduce the incidence of PTB in women at risk of PTB. Although these three proactive, preventative approaches show promise, further research is needed to establish the best agent, the optimum gestational age at commencement and cessation, the ideal candidate patient to achieve a response and the long-term feto-maternal benefits and/or side effects.

Obstetric considerations in the management of pregnancy in kidney transplant recipients

Kidney transplant improves reproductive function; planning for pregnancy is crucial. Prenatal management must address potential fetal complications: preterm delivery, intrauterine growth restriction, low birth weight; as well as maternal: hypertension, preeclampsia, gestational diabetes, acute rejection or graft loss. The latter depends upon timing after transplant, prepregnancy kidney function, and continuation of immunosuppressive agents at appropriate levels. Graft function is not adversely affected if preconception kidney function was normal. Acute rejection, 9%-14%, must be immediately addressed, with kidney biopsy if necessary. Blood pressure should be meticulously managed; serious morbidity results from poor control. Blood pressures >130/80 mmHg require acceptable antihypertensives: beta-blockers, alpha-methyldopa, hydralazine, and calcium channel blockers. Preeclampsia requires seizure prophylaxis with magnesium sulfate, with expeditious delivery. Screening for urinary tract infections with aggressive treatment and for opportunistic infections that may affect the fetus is essential. Surveillance for fetal anomalies, growth, and antenatal testing is important. Steroids for fetal lung maturity are indicated for preterm delivery. Vaginal birth is preferred, reserving cesarean for obstetrical indications, with pain management similar to normal laboring patients. Surveillance for infection postpartum is warranted. Conflicting information exists regarding safety of breastfeeding with immunosuppressive drugs; immunosuppressive medication must be adjusted to prepregnancy levels and contraception counseling addressed.

Cervical length and prediction of preterm delivery

PURPOSE OF REVIEW

To present a summary of the literature and most recent advances in the clinical use of cervical length for the prediction of preterm birth.

RECENT FINDINGS

Cervical length is predictive of preterm birth in all populations studied, including asymptomatic women with prior cone biopsy, mullerian anomalies, or multiple dilation and evacuations. While cervical length remains the most predictive measurement, funneling may add to its predictive value in certain populations. In terms of interventions aimed at preventing preterm birth once a short cervical length has been identified in asymptomatic women, recent data from a meta-analysis of all trials published so far point to the benefit of ultrasound-indicated cerclage in women with both a prior preterm birth and a cervical length less than 25 mm. Other interventions for a short cervical length such as progesterone and indomethacin are promising, but deserve further study before clinical recommendations can be made. In women with symptomatic preterm labor, a recent trial has shown that knowledge of cervical length (and fetal fibronectin) may be beneficial both in terms of time to triage and reduction of preterm birth.

SUMMARY

Transvaginal ultrasound cervical length used as a screening tool for prediction and prevention of preterm birth can significantly improve the health outcomes of pregnant patients and their babies.

A survey of clinician and patient attitudes towards the use of progesterone for women at risk of preterm birth

BACKGROUND AND AIMS

To assess the current use of vaginal progesterone in women at increased risk of preterm birth among practitioners within Australia and New Zealand, and the willingness of both clinicians and women to participate in a randomised controlled trial to further evaluate the role of progesterone in preterm birth.

METHODS

A survey of fellows and members of the Royal Australian and New Zealand College of Obstetricians and Gynaecologists, and women who had a spontaneous preterm birth at less than 34 weeks gestation, at the Women's and Children's Hospital was conducted.

RESULTS

A total of 1430 surveys were distributed to members and fellows, of which 738 (52%) were returned. Of these, 490 were from currently practising obstetricians (34% of total college membership). Twelve of the 490 (2%) respondents indicated that they currently use progesterone in women with a previous spontaneous preterm birth at less than 34 weeks gestation. Of the respondents, 317 (65%) indicated a willingness to participate in a multicentred randomised controlled trial assessing the use of progesterone in women with a previous spontaneous preterm birth at less than 34 weeks gestation. A total of 207 eligible women identified from the hospital database were sent a questionnaire, with responses obtained from 119 women (57%). Overall, women were satisfied with their preterm birth experience. Fifty-two women (44%) indicated a willingness to consider participation in a randomised trial of vaginal progesterone.

CONCLUSIONS

Progesterone is not widely used in Australia and New Zealand for women considered at increased risk of preterm birth. Conducting a randomised trial of vaginal progesterone is feasible.

Management of the pregnant chronic dialysis patient

Although unusual, pregnancy in chronic dialysis patients does occur. In fact, the percent of successful pregnancies in women on chronic dialysis may be increasing. But unfortunately, the rates for premature delivery, neonatal death, maternal hypertension, and preeclampsia in the chronic pregnant dialysis patient are high. Consequently, to have a successful outcome for the pregnant dialysis patient, close collaboration between the patient, her nephrologists, high-risk obstetrician, neonatalogist, dialysis nurse, and nutritionist is required. This article reviews and discusses the need for meticulous attention to anemia management, blood pressure control, fluid status, hemodialysis, and peritoneal dialysis prescription, nutrition, and fetal monitoring in the pregnant chronic dialysis patient.

Progestin inhibits and thrombin stimulates the plasminogen activator/inhibitor system in term decidual stromal cells: implications for parturition

OBJECTIVE

Labor is associated with 'decidual activation' with increased proteolysis and extracellular matrix degradation. The balance between plasminogen activator inhibitor-1 (PAI-1) and urokinase (uPA) and tissue-type plasminogen activator (tPA) is an important determinant of proteolytic activity at the maternal-fetal interface. Thrombin released at the time of placental abruption (decidual hemorrhage) is known to promote decidual proteolysis and uterine contractions. This study investigates the separate and interactive effects of steroid hormones and thrombin on PAI-1, uPA, and tPA expression by term decidual cells (DCs).

STUDY DESIGN

Term DCs were isolated by enzymatic digestion, purified, and depleted of leukocytes. Cells were treated with estradiol (10(-8) mol [E2]), medroxyprogesterone acetate (10(-7) mol [MPA]), both, or vehicle for 7 days. After 24-hour incubation with or without thrombin (0.1-2.5 U/mL), levels of PAI-1, uPA, and tPA in conditioned supernatant were measured by specific ELISA and Western blotting. Levels of PAI-1 and uPA mRNA were measured by quantitative RT-PCR.

RESULTS

In the cultured term DCs, ELISA measurements indicated that basal output of PAI-1 was about 2 logs higher than that of either uPA or tPA (2.5 +/- 0.7 ng/mL per microg protein, 13.4 +/- 6.3 pg/mL per microg protein, and 25.4 +/- 10.8 pg/mL per microg protein, respectively). Although E2 alone did not affect PAI-1 output, MPA and E2+MPA significantly enhanced PAI-1 production (2.5 +/- 0.7 vs 8.2 +/- 2.0 ng/mL per microg protein for E2+MPA [3.3-fold]; P < .01). By contrast, uPA output was inhibited by exposure to MPA (13.4 +/- 6.3 vs 2.6 +/- 1.1 pg/mL per microg protein [0.2-fold]; P < .05), whereas tPA production was not affected by MPA. Thrombin did not significantly affect uPA and tPA production by term DCs. In contrast, in E2+MPA-treated term DCs, thrombin, a hemostatic proinflammatory cytokine, selectively increased PAI-1 output in a dose-dependent fashion, which could be blocked by the selective thrombin inhibitor, hirudin. Western blotting confirmed the effects of MPA and thrombin in elevating secreted levels of PAI-1. Unlike the increase in PAI-1 output elicited by thrombin, term DCs were unresponsive to either of the classic proinflammatory cytokines, TNFalpha or IL-1beta. Corresponding effects on PAI-1 mRNA levels were elicited by MPA and thrombin as seen for PAI-1 protein expression, suggesting that these up-regulatory effects are transcriptionally mediated.

CONCLUSION

Progestin enhanced PAI-1 and inhibited uPA expression by term DCs, which may explain in part the pregnancy-prolonging properties of progesterone as a consequence of inhibited proteolytic activity at the maternal-fetal interface. Thrombin augmented PAI-1 expression in the absence of increased uPA or tPA expression by term DCs, suggesting that abruption-associated decidual proteolysis and preterm labor is mediated primarily by thrombin-enhanced matrix metalloproteinase expression rather than an indirect effect on the plasminogen activator/inhibitor system.

Extreme prematurity: an alcohol-related birth effect

BACKGROUND

Rates of preterm delivery, a major proximate cause of perinatal morbidity and mortality, have been increasing. Prenatal alcohol exposure has been implicated in preterm delivery, although results have been inconsistent due to inadequate control for confounding factors, insufficient power, unreliable and inaccurate assessment of both exposure and gestational age, and lack of stratification of prematurity into severity levels. The purpose of this study was to examine the relation between maternal alcohol, cocaine and cigarette use during pregnancy, and extreme and mild preterm birth.

METHODS

Three thousand one hundred thirty consecutive gravidas were followed prospectively for antenatal substance use and had ultrasound confirmed pregnancy dating.

RESULTS

Alcohol and cocaine, but not cigarette use, were associated with increased risk of extreme preterm delivery after control for potential confounders. For every unit increase in alcohol exposure, risk of extreme preterm delivery increased significantly [odds ratio (OR) 34.8]. Furthermore, in women aged 30+, alcohol exposure was associated with mild prematurity. Abstention from alcohol while continuing to use cocaine and tobacco was related to a decrease in extreme prematurity of 41%.

CONCLUSIONS

The risk of extreme preterm delivery associated with alcohol use is substantial and similar in magnitude to other well-recognized risks. Increased accuracy in identifying exposure and the use of ultrasound to confirm gestational age dating likely contributed to the findings of the current study. These findings suggest that eliminating pregnancy alcohol use might substantially reduce the risk of preterm delivery.