Spontaneously conceived pregnancy after 40: influence of age and obesity on outcome.

OBJECTIVE: The aim of the study was to examine pregnancy outcomes of healthy nulliparous women aged ≥ 40 years at delivery. STUDY DESIGN: The study included 53,480 nulliparous women aged 20 to 29 or ≥ 40 years delivering singleton infants, enrolled in a pregnancy risk assessment program between July 1, 2006, and August 1, 2011. Women reporting medical disorders, tobacco use, or conception with assistive reproductive technology were excluded. Data were grouped by body mass (obese or nonobese) and age (20-29 or ≥ 40 years). Pregnancy outcomes were compared within each body mass group for women aged 20 to 29 years versus ≥ 40 years and between obese and nonobese women aged ≥ 40 years. RESULTS: Within each body mass group, nulliparous women aged ≥ 40 years delivered at a significantly lower gestational age and had a greater incidence of cesarean delivery, gestational diabetes, preterm birth, and both low and very low birth weight infants, compared with controls aged 20 to 29 years. For women aged ≥ 40 years, obesity was associated with higher rates of adverse pregnancy outcomes. CONCLUSION: In healthy women, both advanced maternal age and obesity negatively influence pregnancy outcomes. Women who delay pregnancy until age 40+ years may modify their risk for cesarean section, preterm birth, and low-birth-weight infants by reducing their weight to nonobese levels before conception.

The effect of maternal obesity on pregnancy outcomes of women with gestational diabetes controlled with diet only, glyburide, or insulin.

OBJECTIVE: To examine the effect of obesity on maternal and neonatal outcomes in women diagnosed with gestational diabetes mellitus (GDM) and managed with diet only, glyburide, or insulin. STUDY DESIGN: Women with singleton gestations enrolled for outpatient services diagnosed with GDM and without history of pregnancy-related hypertension at enrollment or in a prior pregnancy were identified in a database. Women with GDM controlled by diet only (n = 3918), glyburide (n = 873), or insulin without prior exposure to oral hypoglycemic agents (n = 2229) were included. Pregnancy outcomes were compared for obese versus nonobese women within each treatment group and also compared across treatment groups within the obese and nonobese populations. RESULTS: Within each treatment group, obesity was associated with higher rates of cesarean delivery, pregnancy-related hypertension, macrosomia, and hyperbilirubinemia (all p < 0.05). Higher rates of pregnancy-related hypertension and hyperbilirubinemia were observed in women receiving glyburide. CONCLUSION: Obesity adversely affects pregnancy outcome in women with GDM. Higher rates of pregnancy-related hypertension and hyperbilirubinemia were observed in pregnant women receiving glyburide.

The association of gestational weight gain per institute of medicine guidelines and prepregnancy body mass index on outcomes of twin pregnancies.

OBJECTIVE: To determine if current recommendations for weight gain in twin pregnancies according to maternal prepregnancy body mass index (PPBMI) influence perinatal outcomes. METHODS: We identified women with twins enrolled in a maternity risk screening and education program with initial screening and prenatal care initiated at <20 weeks and delivery at >23.9 weeks. Women with normal, overweight, or obese PPBMI were included (n = 5129). Pregnancy outcomes were compared between those women with weight gain meeting or exceeding 2009 Institute of Medicine recommendations and patients who did not meet weight gain guidelines. RESULTS: Rates of spontaneous preterm delivery at <35 weeks were higher in all PPBMI groups for those with weight gain below guidelines. In all PPBMI groups, numbers of pregnancies with both infants weighing >2500 g or >1500 g were significantly higher for women gaining weight at or above guidelines. Logistic regression analysis was utilized to assess multivariate impact on outcome of spontaneous preterm delivery at <35 weeks showing that regardless of PPBMI level, women who gain below recommended guidelines are 50% more likely to deliver spontaneously at <35 weeks. CONCLUSION: In twin pregnancies, weight gain below recommended guidelines determined by maternal PPBMI is associated with higher rates of spontaneous preterm delivery at <35 weeks.

Elective delivery at 34°(/)7 to 366(/)7 weeks' gestation and its impact on neonatal outcomes in women with stable mild gestational hypertension.

OBJECTIVE: To examine the frequency of elective delivery and neonatal outcomes in women with stable mild gestational hypertension delivering late preterm. STUDY DESIGN: The frequency of elective delivery between 1995 and 2007 at gestational age of 34°(/)7-366(/)7 weeks (late preterm), 37°(/)7-376(/)7 weeks, and ≥38°(/)7 weeks, as well as neonatal outcomes, were studied in singleton gestation with mild gestational hypertension without proteinuria from a large national database. RESULTS: One thousand eight hundred fifty-eight patients were studied: 607 (33%) were delivered for maternal/fetal reasons and 1251 (67%) were electively delivered. Among the 1251 women delivered electively, 25.5% were late preterm, 24.4% at 37°(/)7-376(/)7 weeks and 50.1% at ≥38°(/)7 weeks' gestation. Neonatal intensive care unit admission, ventilatory assistance, and respiratory distress syndrome were more common in late-preterm infants. There was no maternal/perinatal mortality. CONCLUSION: We found that 25.5% of patients with stable mild gestational hypertension, without any maternal or fetal complication, had iatrogenic elective late-preterm delivery. This practice also was associated with increased rates of neonatal complications and neonatal length of stay.

17-alphahydroxyprogesterone caproate in women with previous spontaneous preterm delivery: does a previous term delivery affect the rate of recurrence?

OBJECTIVE: The purpose of this study was to determine the role of previous term delivery on the rate of recurrent preterm birth in women with previous spontaneous preterm delivery (SPTD) who receive 17-alphahydroxyprogesterone caproate (17P) therapy. STUDY DESIGN: Women with singleton gestations who were receiving 17P therapy were studied. Rates of recurrent SPTD were compared for 1 or ≥2 SPTD with and without a previous term delivery. RESULTS: Five thousand one hundred two women had 1 previous SPTD, and 2217 women had ≥2 SPTDs. In women with 1 previous SPTD, a previous term delivery had lower rates of SPTD at <35 weeks (8.4% vs 11.2%; P = .002) and preterm delivery at <32 weeks (4.7% vs 6.2%; P = .027) compared with those women with no such history. No differences were found for SPTD at <35 weeks with ≥2 SPTDs. CONCLUSION: In patients who received 17P therapy with 1 previous SPTD, a previous term delivery confers a reduction in risk of preterm delivery at <37, <35, and <32 weeks' gestation; such reduction is not evident with ≥2 previous SPTDs.

Influence of gestational age and reason for prior preterm birth on rates of recurrent preterm delivery.

OBJECTIVE: We sought to compare rates of recurrent spontaneous preterm birth (SPTB) in women receiving 17-α-hydroxyprogesterone caproate (17P) with prior SPTB due to preterm labor (PTL) vs preterm premature rupture of membranes (PPROM). STUDY DESIGN: Women with singleton gestation having 1 prior SPTB enrolled at 16-24.9 weeks' gestation for weekly outpatient 17P administration were identified from a database. Rates of recurrent SPTB were compared between those with prior SPTB due to PTL or PPROM overall and by gestational age at prior SPTB. RESULTS: Records from 2123 women were analyzed. The prior PTL group vs the prior PPROM group experienced higher rates of recurrent SPTB at <37 weeks (29.7% vs 22.9%, P = .004), <35 weeks (14.0% vs 9.1%, P = .004), and <32 weeks (5.9% vs 3.3%, P = .024), respectively. CONCLUSION: Reason and gestational age of prior SPTB influence the likelihood of recurrent SPTB in women receiving 17P prophylaxis.

Treatment of severe nausea and vomiting of pregnancy with subcutaneous medications.

We examined treatment outcomes in women with severe nausea and vomiting of pregnancy (NVP) receiving outpatient nursing support and either subcutaneous metoclopramide or subcutaneous ondansetron via a microinfusion pump. Among women receiving outpatient nursing services, we identified those diagnosed with severe NVP having a Pregnancy-Unique Quantification of Emesis (PUQE) score of greater than 12 at enrollment and prescribed either metoclopramide (N = 355) or ondansetron (N = 521) by their physician. Maternal characteristics, response to treatment, and start versus stop values were compared between the medication groups. Allocation to group was based on intention-to-treat protocol. Maternal characteristics were similar between the groups. Days to reduction in PUQE score levels were similar (median 2 days, metoclopramide; 3 days, ondansetron; P = 0.206). Alteration from metoclopramide to ondansetron (31.8%) was more frequent than alteration from ondansetron to metoclopramide (4.4%; P < 0.001). Improvement of NVP symptoms and reduced need for hospitalization was noted with both medications. Treatment with either metoclopramide or ondansetron resulted in significant improvement of NVP symptoms with half of women showing a reduction from severe symptoms to moderate or mild symptoms within 3 days of treatment initiation. Alteration in treatment was significantly greater in patients initially prescribed metoclopramide.

The effect of new antepartum weight gain guidelines and prepregnancy body mass index on the development of pregnancy-related hypertension.

We evaluated the impact of adherence to the new Institute of Medicine weight gain guidelines within each prepregnancy body mass index (PPBMI) category on the development of pregnancy-related hypertension (PRH). Patients with singleton term deliveries (≥37 weeks) with documented PPBMI and pregnancy weight gain information were identified from a database of women enrolled for outpatient nursing services. Included were women without history of cardiovascular disease, PRH, or diabetes at initiation of services (N = 7676). Data were stratified by PPBMI (underweight = < 18.5 kg/m(2); normal weight = 18.5 to 24.9 kg/m(2); overweight = 25.0 to 29.9 kg/m(2); obese = ≥ 30.0 kg/m(2)). PRH rates were compared overall and within each PPBMI group for those women gaining less than recommendations, within recommendations, and above recommendations using Pearson's chi-square and Kruskal-Wallis H test statistics. Overall, PRH rates were 5.0%, 5.4%, and 10.8% for less than, within, and above recommendation groups, respectively (P < 0.001). Above recommendation weight gain resulted in higher PRH incidence in each PPBMI category (underweight 7.6%, normal weight 6.2%, overweight 12.4%, and obese 17.0%), reaching statistical significance in all but the underweight PPBMI group. Excessive weight gain above established guidelines was associated with increased rates of PRH. Regardless of PPBMI, women should be counseled to avoid excessive weight gain during pregnancy.

The influence of maternal age on pregnancy outcome in nulliparous women with twin gestation.

We sought to determine if outcomes of nulliparous twin pregnancies differ based on maternal age. Nulliparous women with current twin pregnancies were identified from a database of women enrolled for outpatient nursing surveillance. Data were stratified into four groups by maternal age: less than 20, 20 to 34, 35 to 39, and greater than or equal to 40 years. Maternal and neonatal outcomes for women less than 20, 35 to 39, and 40 or more were compared with 20- to 34-year-old controls using Kruskal-Wallis, Mann-Whitney, and Pearson chi-square analyses. We analyzed 2144 nulliparous twin pregnancies. Patients ≥35 years (34 to 39, 78.5% or ≥40, 85.9%) were more likely to have cesarean deliveries compared with controls 20 to 34 years old (71.2%). Women aged 35 to 39 were less likely to deliver at <37 weeks, and women in the ≥40 group were less likely to deliver at <35 weeks due to spontaneous preterm labor compared with the controls. Neonates born to women aged 35 to 39 had a greater gestational age at delivery and larger average birth weight than controls. Maternal and neonatal outcomes were not adversely influenced by advanced maternal age in nulliparous women carrying twin gestations.

Impact of prior gestational age at preterm delivery on effectiveness of 17-alpha-hydroxyprogesterone caproate in practice.

OBJECTIVE: We sought to examine if 17-alpha-hydroxyprogesterone caproate (17OHPC) effectiveness is dependent on the earliest gestational age (GA) at prior spontaneous preterm birth (SPTB) when administered in the clinical setting. STUDY DESIGN: Women enrolled for outpatient services with current singleton gestation and > or =1 prior SPTB between 20-36.9 weeks were identified. Data were divided into 3 groups according to earliest GA of prior SPTB (20-27.9, 28-33.9, and 34-36.9 weeks). We compared GA at delivery of current pregnancy and incidence of recurrent SPTB between women enrolled in outpatient 17OHPC administration program (n = 2978) and women receiving other outpatient services without 17OHPC (n = 1260). RESULTS: Rates of recurrent SPTB for those with and without 17OHPC prophylaxis, respectively, according to GA at earliest SPTB were: 20-27.9 weeks at earliest SPTB, 32.2% vs 40.7%, P = .025; 28-33.9 weeks at earliest SPTB, 34.1% vs 45.5%, P < .001; and 34-36.9 weeks at earliest SPTB, 29.3% vs 38.8%, P < .001. CONCLUSION: 17OHPC given to prevent recurrent SPTB is effective regardless of GA at earliest SPTB.

The risk for preterm labor in women receiving 17 alpha-hydroxyprogesterone caproate prophylaxis for preterm birth prevention.

We sought to identify maternal or clinical characteristics of women likely to develop preterm labor (PTL) at <34 weeks' gestation while receiving 17 alpha-hydroxyprogesterone caproate (17P) prophylaxis. Current singleton gestations with prior preterm delivery enrolled for outpatient 17P administration at <27 weeks' gestation were identified ( N = 1177). Maternal and clinical characteristics were compared between women hospitalized and diagnosed with PTL at <34 weeks' gestation (PTL group, N = 270) and those without PTL (No PTL group, N = 660). PTL at <34 weeks' gestation occurred in 270/1177 (22.9%) of patients receiving 17P prophylaxis (mean gestational age at diagnosis was 28.3 +/- 4.0 weeks). Recurrent preterm delivery occurred in 73.3% of women with PTL at <34 weeks. Maternal age, marital status, race, tobacco use, cerclage, gestational age at start of 17P, and Medicaid status were similar between the groups. Women developing PTL at <34 weeks were more likely to have >1 prior preterm delivery than those without PTL (35.2% versus 25.9%, P = 0.006, odds ratio [95% confidence interval] 1.5 [1.1, 2.1]). Women receiving 17P prophylaxis remain at increased risk for PTL and preterm birth. Patient education and surveillance for PTL symptoms may be warranted in women with a history of more than one prior preterm delivery.

An examination of the clinical benefits and cost-effectiveness of tocolytic replacement following recurrent preterm labor.

We examined pregnancy outcomes in women receiving nifedipine tocolysis having recurrent preterm labor (RPTL). Singleton gestations enrolled for outpatient nursing surveillance and prescribed nifedipine tocolysis were identified (N = 4748). Women hospitalized for RPTL at <35 weeks then resuming outpatient surveillance were included (N = 1366). Pregnancy outcomes of women resuming nifedipine (N = 830) were compared with those having an alteration in treatment to continuous subcutaneous terbutaline (N = 536). Overall, 56.7% (2692/4748) experienced RPTL. Half (50.7%) were stabilized and resumed outpatient surveillance with nifedipine or continuous subcutaneous terbutaline. Infants from women resuming nifedipine versus those with alteration of treatment to terbutaline were more likely to deliver at <35 weeks (28.0% versus 13.8%), weigh <2500 g (32.9% versus 20.3%), and require a stay in the neonatal intensive care unit (34.0% versus 23.1%), all P < 0.001. Alteration of tocolytic treatment following RPTL resulted in a decreased incidence of preterm birth and low birth weight, resulting in less admission to the neonatal intensive care unit and fewer nursery days.

The impact of maternal obesity on the incidence of adverse pregnancy outcomes in high-risk term pregnancies.

We investigated the impact of maternal obesity on pregnancy outcomes. Women with normal or obese body mass index (BMI) who delivered singleton infants at term were identified from a perinatal database. Rates of pregnancy complications and neonatal outcomes were compared between women with normal prepregnancy BMI (20 to 24.9 kg/m (2), N = 9171) and those with an obese prepregnancy BMI (> or = 30, N = 3744). Rates of pregnancy complications and neonatal outcomes were also evaluated by the level of obesity (obese [30 to 34.9 kg/m (2), N = 2106], severe obesity [35 to 39.9 kg/m (2), N = 953], and morbid obesity [> or = 40 kg/m (2), N = 685]). Rates of gestational diabetes (12.0% versus 3.7%, P < 0.001, odds ratio [95% confidence interval] = 3.5 [3.0, 4.1]) and gestational hypertension (30.9% versus 9.0%, P < 0.001, odds ratio [95% confidence interval] = 4.5 [4.1, 5.0]) were higher for obese versus normal BMI gravidas, respectively. Women with morbid or severe obesity had a greater incidence of gestational diabetes than women with an obese (30 to 34.9 kg/m (2)) or normal BMI (14.1%, 16.4%, 9.6%, and 3.7%, respectively; P < 0.05). The incidence of gestational hypertension increased with maternal BMI (9.0% normal, 25.5% obese, 33.7% severe, 43.4% morbid; all pairwise comparisons P < 0.05). Obese versus normal BMI was associated with more higher-level nursery admissions (8.2% versus 5.8%) and large-for-gestational age infants (12.3% versus 6.5%; P < 0.001). Obesity places a term pregnancy at risk for adverse maternal and neonatal outcomes.

The impact of acute tocolysis on neonatal outcome in women hospitalized with preterm labor at 32 to 34 weeks' gestation.

We compared neonatal outcomes from singleton pregnancies in women hospitalized with preterm labor (PTL) at 32 0/7 to 34 6/7 weeks managed with and without acute tocolysis. Women enrolled for outpatient surveillance who were hospitalized and diagnosed with PTL between 32 0/7; to 34 6/7 weeks' gestation without conditions necessitating interventional delivery during hospitalization were identified ( N = 2921). Patients with contraindications to pregnancy prolongation were excluded ( N = 168). Data were compared between patients whose clinical management included tocolysis ( N = 2342) and patients in whom tocolysis was not utilized ( N = 411). The incidence of preterm birth (77.9% versus 48.1%), low birth weight (48.9% versus 16.7%), neonatal intensive care unit admission (41.4% versus 16.2%), and nursery length of stay > 7 days (28.0% versus 9.7%) were all higher in women not receiving acute tocolysis compared with the acute tocolysis group (all P < 0.001). Using acute tocolysis to prolong pregnancy in patients hospitalized with PTL at 32 0/7 to 34 6/7 weeks' gestation is associated with improved neonatal outcomes.

Management of recurrent preterm labor in twin gestations with nifedipine tocolysis.

We examined outcomes of twin pregnancies complicated by recurrent preterm labor receiving nifedipine tocolysis. In a retrospective study design, twin pregnancies receiving outpatient preterm labor surveillance services and oral nifedipine tocolysis following a diagnosis of preterm labor were identified from a database ( N = 1421). Eligible for inclusion were patients subsequently rehospitalized with recurrent preterm labor symptoms ( N = 862). Included were patients at < 35 weeks' gestation, having intact membranes, and remaining undelivered for > 48 hours after recurrent preterm labor ( N = 656). Pregnancy outcomes of women resuming nifedipine tocolysis ( N = 418) following hospitalization were compared with those having an alteration in treatment ( N = 238) to continuous subcutaneous terbutaline. Alteration of tocolytic treatment versus resuming nifedipine resulted in increased pregnancy prolongation (34.7 +/- 18.8 days versus 27.5 +/- 19.9 days, P < 0.001), with delivery of fewer low birth weight (67.2% versus 78.3%, P < 0.001) and very low birth weight infants (6.5% versus 15.0%, P < 0.001) and a decreased incidence of neonatal intensive care unit admission (44.7% versus 52.9%, P = 0.005). In twin pregnancies receiving nifedipine tocolysis, alteration of tocolytic treatment to subcutaneous terbutaline following hospitalization for recurrent preterm labor symptoms had a positive impact on pregnancy prolongation and neonatal outcomes.

The impact of maternal body mass on the effectiveness of 17 alpha-hydroxyprogesterone caproate.

OBJECTIVE: To examine the impact of maternal prepregnancy body mass index (BMI) on rates of recurrent preterm delivery (PTD) in women receiving 17alpha-hydroxyprogesterone caproate (17P) prophylaxis. STUDY DESIGN: The study population was identified from a large perinatal database containing prospectively collected information from women at high risk for PTD. We included patients with a current singleton pregnancy and a history of PTD who received weekly nursing visits and 17P 250 mg intramuscular injections beginning at 16.0 to 20.9 weeks' gestation. The data were stratified by number of prior PTDs (1 or >1) and maternal prepregnancy BMI (lean, normal, overweight and obese). Primary study outcomes included the rates of recurrent PTD at <35 and 32 weeks' gestation, and pregnancy loss at <24 weeks' gestation. RESULTS: Delivery outcomes for 606 women receiving 17P were analyzed. There were no significant differences found in the incidence of preterm labor, the rates of recurrent PTD or pregnancy loss at <35, 32 or 24 weeks between the BMI groups. CONCLUSION: Maternal prepregnancy BMI does not appear to influence the rates of recurrent PTD in women with singleton gestation receiving 17P prophylaxis. Larger studies are needed to confirm our findings.

Adverse pregnancy outcomes in women with nausea and vomiting of pregnancy.

OBJECTIVE: To examine the influence of nausea and vomiting of pregnancy (NVP) on pregnancy outcomes. METHODS: Outcomes were compared for primigravidas with a current singleton gestation enrolled at <20 weeks' gestation in a maternity risk screening and education program (n = 81 486). Patient-reported maternal characteristics and pregnancy outcomes were compared for women with and without NVP and within the NVP group for those with and without poor weight gain. RESULTS: 6.4% of women reported NVP as a pregnancy complication. Women reporting NVP were more likely to be younger, obese, single and smoke. They had higher rates of preterm delivery, pregnancy-induced hypertension and low birth weight <2500 g. Almost one-quarter of women with NVP had lower than recommended weight gain. Poor weight gain was associated with a higher incidence of adverse outcomes. Obesity, tobacco use and poor pregnancy weight gain independently increased the odds of an adverse outcome. CONCLUSION: NVP and subsequent poor weight gain may be associated with adverse pregnancy outcomes.

Pregnancy outcomes following bariatric surgery.

OBJECTIVE: To compare pregnancy outcomes postbariatric surgery for women who remain obese at conception to those who were not obese. METHODS: From a database of women who received outpatient perinatal services, we identified women with a history of bariatric surgery who are currently pregnant with a singleton gestation. Available maternal characteristics and pregnancy outcomes were compared between women whose prepregnancy body mass index (PPBMI) remained in the obese range (≥30 kg/m(2)) and those with a PPBMI of <30 kg/m(2) using Fisher exact test, independent Student's t test, and Mann-Whitney U test statistics. RESULTS: Of the 102 women identified, 52 (51%) were obese and 50 (49%) were not obese at conception. No differences were observed in maternal age, marital status, years from surgery to delivery, development of gestational diabetes, gestational age at delivery, neonatal intensive care unit (NICU) admission, or nursery days. Maternal obesity (≥30 kg/m(2)) postbariatric surgery was associated with higher rates of cesarean delivery (63.5% vs. 36.0%, p=0.010) and development of pregnancy-related hypertension (36.5% vs. 8.0%, p=0.001) compared to nonobese women (<30 kg/m(2)). CONCLUSIONS: Postbariatric surgery, an optimal goal should be to achieve a nonobese weight status before conception to reduce maternal complications, such as pregnancy-related hypertension and cesarean delivery.

The reliability of patient-reported pregnancy outcome data.

Pregnancy and neonatal outcome information is frequently used in disease management to evaluate the cost-effectiveness of prenatal interventions and for other research and reporting activities. The purpose of this study was to determine if a telephone interview process is a reliable methodology for collecting pregnancy outcomes. High-risk patients from a large maternal-fetal medicine practice who received outpatient preterm labor management services from January 1996 to June 2001 were identified. Patient-reported pregnancy outcome data for 285 mothers and 478 infants were collected via a telephone interview by a perinatal nurse and compared to pregnancy outcome data abstracted from the maternal and infant hospital records. Overall, concordance and/or Kappa coefficients between maternal report and the medical record were high for delivery date (96.4%), birth weight within 100 grams (88.9%), Cesarean delivery (99.0%, Kappa = 0.98), and high-level nursery admission (91.2%, Kappa = 0.82). Both singleton and multiple gestation types accurately reported pregnancy outcome information. A telephone interview with a skilled nurse can be a reliable methodology for collection of valuable clinical and research data related to pregnancy outcome. Data collected in this manner and maintained in a database may be used with a high level of confidence by health care providers, payers, and researchers.

The use of 17 alpha-hydroxyprogesterone caproate (17p) in women with cervical cerclage.

Our objective was to compare the incidence of recurrent spontaneous preterm delivery (SPTD) in patients with cervical cerclage treated with weekly 17 alpha-hydroxyprogesterone caproate (17P) injections versus daily outpatient nursing surveillance (ONS) without 17P. Included in this retrospective cohort study were singleton gestations with cerclage placed at the discretion of the provider due to prior SPTD, delivering between January 1, 2004 and May 1, 2006. The study group (n = 232) consisted of women receiving once-weekly nursing visit and 17P injection. The control group (n = 1650) consisted of women enrolled for ONS (twice-daily electronic uterine contraction monitoring and nursing assessment). Data were further stratified by the number of prior preterm deliveries (1, > 1). Primary study outcome was the incidence of SPTD. No difference in rates of recurrent SPTD at < 37 or < 35 weeks were observed between the study and control groups. Study patients were less likely to be diagnosed with preterm labor (PTL) than controls (45.7% versus 70.8%, respectively; P < 0.001). The incidence of preterm premature rupture of membranes was similar between the groups (8.6% versus 8.1%; P = 0.770). We concluded that the incidence of recurrent SPTD was similar in women with cerclage treated with 17P or ONS, although women receiving 17P had a lower incidence of PTL. This benefit of 17P should be considered when managing patients with prior SPTD and cerclage.