Effect of Treatment of Mild Gestational Diabetes on Long-Term Maternal Outcomes.

OBJECTIVE: The main purpose of this article is to evaluate whether identification and treatment of women with mild gestational diabetes mellitus (GDM) during pregnancy affects subsequent maternal body mass index (BMI), anthropometry, metabolic syndrome, and risk of diabetes. STUDY DESIGN: This is a follow-up study of women who participated in a randomized controlled treatment trial for mild GDM. Women were enrolled between 5 and 10 years after their index pregnancy. Participants underwent blood pressure, height, weight, and anthropometric measurements by trained nursing personnel using a standardized approach. A nurse-assisted questionnaire regarding screening and treatment of diabetes or hypercholesterolemia, diet, and physical activity was completed. Laboratory evaluation included fasting serum glucose, fasting insulin, oral glucose tolerance test, and a lipid panel. Subsequent diabetes, metabolic syndrome, obesity, and adiposity in those diagnosed with mild GDM and randomized to nutritional counseling and medical therapy (treated) were compared with those who underwent routine pregnancy management (untreated). Multivariable analyses were performed adjusting for race/ethnicity and years between randomization and follow-up visit. RESULTS: Four-hundred fifty-seven women with mild GDM during the index pregnancy were included in this analysis (243 treated; 214 untreated) and evaluated at a median 7 years after their index pregnancy. Baseline and follow-up characteristics were similar between treatment groups. Frequency of diabetes (9.2 vs. 8.5%, p =0.80), metabolic syndrome (32.2 vs. 34.3%, p =0.63), as well as adjusted mean values of homeostasis model assessment for insulin resistance (2.5 vs. 2.3, p =0.11) and BMI (29.4 vs. 29.1 kg/m2, p =0.67) were also not different. CONCLUSION: Identification and treatment of women with mild GDM during pregnancy had no discernible impact on subsequent diabetes, metabolic syndrome, or obesity 7 years after delivery.

Can differences in obstetric outcomes be explained by differences in the care provided? The MFMU Network APEX study.

OBJECTIVE: The purpose of this study was to determine whether hospital differences in the frequency of adverse obstetric outcomes are related to differences in care. STUDY DESIGN: The Assessment of Perinatal EXcellence cohort comprises 115,502 women and their neonates who were born in 25 hospitals in the United States between March 2008 and February 2011. Hierarchical logistic regression was used to quantify the amount of variation in postpartum hemorrhage, peripartum infection, severe perineal laceration, and a composite adverse neonatal outcome among hospitals that is explained by differences in patient characteristics, hospital characteristics, and obstetric care provided. RESULTS: The study included 115,502 women. For most outcomes, 20-40% of hospital differences in outcomes were related to differences in patient populations. After adjusting for patient-, provider-, and hospital-level factors, multiple care processes were associated with the predefined adverse outcomes; however, these care processes did not explain significant variation in the frequency of adverse outcomes among hospitals. Ultimately, 50-100% of the interhospital variation in outcomes was unexplained. CONCLUSION: Hospital differences in the frequency of adverse obstetric outcomes could not be explained by differences in frequency of types of care provided.

Risk-adjusted models for adverse obstetric outcomes and variation in risk-adjusted outcomes across hospitals.

OBJECTIVE: Regulatory bodies and insurers evaluate hospital quality using obstetrical outcomes, however meaningful comparisons should take preexisting patient characteristics into account. Furthermore, if risk-adjusted outcomes are consistent within a hospital, fewer measures and resources would be needed to assess obstetrical quality. Our objective was to establish risk-adjusted models for 5 obstetric outcomes and assess hospital performance across these outcomes. STUDY DESIGN: We studied a cohort of 115,502 women and their neonates born in 25 hospitals in the United States from March 2008 through February 2011. Hospitals were ranked according to their unadjusted and risk-adjusted frequency of venous thromboembolism, postpartum hemorrhage, peripartum infection, severe perineal laceration, and a composite neonatal adverse outcome. Correlations between hospital risk-adjusted outcome frequencies were assessed. RESULTS: Venous thromboembolism occurred too infrequently (0.03%; 95% confidence interval [CI], 0.02-0.04%) for meaningful assessment. Other outcomes occurred frequently enough for assessment (postpartum hemorrhage, 2.29%; 95% CI, 2.20-2.38, peripartum infection, 5.06%; 95% CI, 4.93-5.19, severe perineal laceration at spontaneous vaginal delivery, 2.16%; 95% CI, 2.06-2.27, neonatal composite, 2.73%; 95% CI, 2.63-2.84). Although there was high concordance between unadjusted and adjusted hospital rankings, several individual hospitals had an adjusted rank that was substantially different (as much as 12 rank tiers) than their unadjusted rank. None of the correlations between hospital-adjusted outcome frequencies was significant. For example, the hospital with the lowest adjusted frequency of peripartum infection had the highest adjusted frequency of severe perineal laceration. CONCLUSION: Evaluations based on a single risk-adjusted outcome cannot be generalized to overall hospital obstetric performance.

Intrapartum management of category II fetal heart rate tracings: towards standardization of care.

There is currently no standard national approach to the management of category II fetal heart rate (FHR) patterns, yet such patterns occur in the majority of fetuses in labor. Under such circumstances, it would be difficult to demonstrate the clinical efficacy of FHR monitoring even if this technique had immense intrinsic value, since there has never been a standard hypothesis to test dealing with interpretation and management of these abnormal patterns. We present an algorithm for the management of category II FHR patterns that reflects a synthesis of available evidence and current scientific thought. Use of this algorithm represents one way for the clinician to comply with the standard of care, and may enhance our overall ability to define the benefits of intrapartum FHR monitoring.

The impact of tobacco use on preterm premature rupture of the membranes.

OBJECTIVE: To determine if tobacco use increases the incidence of preterm premature rupture of the membranes (pPROM) or alters perinatal outcomes after pPROM. STUDY DESIGN: This is a secondary analysis of the databases of three completed Eunice Kennedy Shriver National Institute of Child Health and Human Development-supported Maternal Fetal Medicine Units Network studies. Self-reported tobacco exposure data was obtained. Its relationship with the incidence of pPROM and associated neonatal outcome measures were assessed. RESULTS: There was no difference in the incidence of pPROM when comparing nonsmokers to those using tobacco. Although a trend was seen between the incidence of pPROM and the amount smoked, this did not reach statistical significance. Among the patients with pPROM, the use of tobacco was not associated with an increase in perinatal morbidity. CONCLUSION: Our data do not support a significant relationship between tobacco use and pPROM.

17 alpha-hydroxyprogesterone caproate to prevent prematurity in nulliparas with cervical length less than 30 mm.

OBJECTIVE: We sought to evaluate whether 17 alpha-hydroxyprogesterone caproate (17-OHP) reduces preterm birth (PTB) in nulliparous women with a midtrimester cervical length (CL) <30 mm. STUDY DESIGN: In this multicenter randomized controlled trial, nulliparous women with a singleton gestation between 16 and 22 3/7 weeks with an endovaginal CL <30 mm (<10th percentile in this population) were randomized to weekly intramuscular 17-OHP (250 mg) or placebo through 36 weeks. The primary outcome was PTB <37 weeks. RESULTS: The frequency of PTB did not differ between the 17-OHP (n = 327) and placebo (n = 330) groups (25.1% vs 24.2%; relative risk, 1.03; 95% confidence interval, 0.79-1.35). There also was no difference in the composite adverse neonatal outcome (7.0% vs 9.1%; relative risk, 0.77; 95% confidence interval, 0.46-1.30). CONCLUSION: Weekly 17-OHP does not reduce the frequency of PTB in nulliparous women with a midtrimester CL <30 mm.

Abdominal cerclage for the treatment of recurrent cervical insufficiency: laparoscopy or laparotomy?

OBJECTIVE: The purpose of this study was to compare the efficacy of traditional abdominal cerclage (AC) with laparoscopic cerclage (LC). STUDY DESIGN: Eligible women had at least 1 second trimester pregnancy loss due to cervical insufficiency, and had undergone at least 1 failed transvaginal cerclage. A prospective cohort of patients undergoing LC was compared with a historical control group of patients who had AC. A successful primary outcome was defined as delivery of a viable infant with neonatal survival. RESULTS: We were able to evaluate 19 pregnancies following unique abdominal cerclage placement, 12 laparoscopic and 7 at the time of laparotomy. Nine of 12 (75%) undergoing LC and 5 of 7 (71%) pregnancies undergoing AC successfully delivered a viable infant (P = .63). LC during pregnancy was successful in 4 of 5 (80%) cases as compared to 3 of 5 (60%) cases with AC during pregnancy (P = 1.0). CONCLUSION: Operative laparoscopy is a safe and effective alternative to laparotomy for the placement of abdominal cerclage.

Maternal plasma concentrations of the soluble tumor necrosis factor receptor 2 are increased prior to the diagnosis of preeclampsia.

OBJECTIVE: Soluble receptor levels of tumor necrosis factor (sTNF-R)-1 and -2 are increased during preeclampsia. We postulated the increase preceded overt disease. STUDY DESIGN: Archived plasma from the Eunice Kennedy Shriver National Institute of Child Health and Human Development aspirin to prevent preeclampsia in high risk women trial were used to measure serial sTNF-R1 and sTNF-R2 (enrollment, 24-28 week's gestation) in 986 women (577 also sampled at 34-38 weeks). RESULTS: Preeclampsia incidence was 21.2%. sTNF-R2 levels were higher at enrollment (P = .02) and weeks 24-28 (P = .01) in women who eventually developed preeclampsia. The magnitude of increase from baseline of both receptors was significantly greater in women who developed preeclampsia in the future. Women with week 24-28 sTNF-R2 levels in the highest quartile had significantly increased odds to develop preeclampsia (P = .03 vs quartile 1). This association was observed in the placebo but not the aspirin arm (P

The NICHD-MFMU antibiotic treatment of preterm PROM study: impact of initial amniotic fluid volume on pregnancy outcome.

OBJECTIVE: The purpose of this study was to evaluate the associations between measured amniotic fluid volume and outcome after preterm premature rupture of membranes (PROM). STUDY DESIGN: This was a secondary analysis of 290 women, with singleton pregnancies, who participated in a trial of antibiotic therapy for preterm PROM at 24(0) to 32(0) weeks. Each underwent assessment of the 4 quadrant amniotic fluid index (AFI) and a maximum vertical fluid pocket (MVP) before randomization. The impact of low AFI (< 5.0 cm) and low MVP (< 2.0 cm) on latency, amnionitis, neonatal morbidity, and composite morbidity (any of death, RDS, early sepsis, stage 2-3 necrotizing enterocolitis, and/or grade 3-4 intraventricular hemorrhage) was assessed. Logistic regression controlled for confounding factors including gestational age at randomization, GBS carriage, and antibiotic study group. RESULTS: Low AFI and low MVP were identified in 67.2% and 46.9% of women, respectively. Delivery occurred by 48 hours, 1 and 2 weeks in 32.4%, 63.5% and 81.7% of pregnancies, respectively. Both low AFI and low MVP were associated with shorter latency (P < .001), and with a higher rate of delivery at 48 hours, 1, and 2 weeks (P = .02 for each). However, neither test offered significant additional predictive value over the risk in the total population. Low AFI and low MVP were not associated with increased amnionitis. After controlling for other factors, both low MVP and low AFI were associated with shorter latency (P < or = .002), increased composite morbidity (P = .03), and increased RDS (P < or = .01), but not with increased neonatal sepsis (P = .85) or pneumonia (P = .53). Alternatively, after controlling for fluid volume, gestational age, and GBS carriage, the antibiotic study group had longer latency, and suffered less common primary outcomes and neonatal sepsis. CONCLUSION: Oligohydramnios should not be a consideration in determining which women will be candidates for expectant management or antibiotic treatment when it is identified at initial assessment of preterm PROM remote from term.

Are women with recurrent spontaneous preterm births different from those without such history?

OBJECTIVE: This study was undertaken to determine whether women with recurrent spontaneous preterm births (rSPBs) have different clinical characteristics or systemic markers than those with isolated preterm (iSPBs) or recurrent term births (rTBs), when assessed remote from delivery. STUDY DESIGN: We compared clinical characteristics and findings (including cervical ultrasound, bacterial vaginosis, fetal fibronectin), maternal plasma markers obtained at 22 to 24 weeks' gestation (inflammatory cytokines, cortisol, and corticotrophin-releasing hormone), between women with rSPBs (2 or 3 consecutive SPBs and no TBs), iSPBs (1 SPB and 1 or 2 TBs), and rTBs (2 or 3 consecutive TBs and no SPBs). RESULTS: A total of 1257 women met our inclusion criteria; 47 rSPBs, 241 iSPBs (80 current and 161 prior iSPBs), and 969 rTBs. Before pregnancy, women with rSPBs had lower weights (P < .0001) and body mass indexes (BMIs) (P < .001), and were more likely to be less than 100 lbs (P = .008) or less than 19.8 kg/m2 BMI (P = .001). At 22 to 24 weeks those with rSPBs remained lighter and leaner, and had more advanced Bishop scores than iSPBs and rTBs. Ultrasound demonstrated progressive decrease in cervical length for those with rTBs, prior iSPBs, current iSPBs, and rSPBs, and also progressively more frequent short cervixes with worsening history (P < .001). Cervical length was shorter for women of lower pregravid weight and BMI, but not with shorter height. At 22 to 24 weeks, women with rSPBs had more common uterine contractions and tocolytic agents, but not more infections or antibiotic therapy. Those with an SPB in the current gestation had higher fetal fibronectin levels and more frequent vaginal bleeding, regardless of prior outcome. Maternal cortisol and corticotrophin-releasing hormone were higher in women with iSPBs and rSPBs than in rTB controls, (P = .001 and .0027), a finding more apparent with SPB in the current pregnancy. However, maternal cytokines were not increased with either iSPBs or rSPBs. CONCLUSION: Women with rSPBs are leaner, contract more, have shorter cervixes, and have more advanced Bishop scores than women with iSPBs or rTBs.

Differences in inflammatory cytokine and Toll-like receptor genes and bacterial vaginosis in pregnancy.

OBJECTIVE: This study was undertaken to estimate the frequency of inflammatory cytokine and Toll-like receptor gene polymorphisms in women with and without bacterial vaginosis (BV) in pregnancy. STUDY DESIGN: A secondary analysis was performed of pregnant women at less than 30 weeks' gestation enrolled as part of 2 multicenter studies. Eight hundred eighty-five women were assessed for BV (defined as Nugent's vaginal Gram stain score 7-10 and a pH > 4.5). Comparisons were made between women with or without BV. Extracted maternal DNA was analyzed for 7 cytokine (interleukin [IL] 1beta-511, IL1beta Exon 5 +3954, IL6-174, IL8-845, IL10-1082, tumor necrosis factor alpha-238 [TNFalpha-238], TNFalpha-308) and 2 Toll-like receptor (TLR-4 299, TLR-4 399) gene polymorphisms. RESULTS: BV was diagnosed in 497 women and 388 did not have BV. Genotype and allele frequency analyses revealed associations with BV and polymorphisms at the IL1beta Exon 5 +3954, IL6-174, IL10-1082, and TLR-4 399 loci. Women with BV were less likely to be homozygous (C/C) for IL1beta Exon 5 +3954 (P = .04). Women with BV were also less likely to have polymorphisms at the IL10-1082 (P = .03) and TLR-4 399 (P = .04) loci in the univariate analysis. Women with BV were more likely to be heterozygous (G/C) for the IL6-174 genotype (P < .0001). Multivariate analysis, controlling for maternal race, confirmed the following associations with BV: IL1beta Exon 5 +3954 (odds Ratio [OR] 0.5, 95% CI 0.3-0.9) and IL6-174 (OR 2.2, 95% CI 1.6-3.1). In addition, polymorphism at the IL8-845 locus was associated with a decreased risk for BV (OR 0.6, 95% CI 0.4-1.0). CONCLUSION: After controlling for race, polymorphisms at the IL1beta Exon 5 +3954, IL6-174, and IL8-845 loci were associated with an altered rate of BV in pregnancy.

Frequency of and factors associated with severe maternal morbidity.

OBJECTIVE: To estimate the frequency of severe maternal morbidity, assess its underlying etiologies, and develop a scoring system to predict its occurrence.Supplemental Digital Content is Available in the Text. METHODS: This was a secondary analysis of a Eunice Kennedy Shriver National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network cohort of 115,502 women and their neonates born in 25 hospitals across the United States over a 3-year period. Women were classified as having severe maternal morbidity according to a scoring system that takes into account the occurrence of red blood cell transfusion (more than three units), intubation, unanticipated surgical intervention, organ failure, and intensive care unit admission. The frequency of severe maternal morbidity was calculated and the underlying etiologies determined. Multivariable analysis identified patient factors present on admission that were independently associated with severe maternal morbidity; these were used to develop a prediction model for severe maternal morbidity. RESULTS: Among 115,502 women who delivered during the study period, 332 (2.9/1,000 births, 95% confidence interval 2.6-3.2) experienced severe maternal morbidity. Postpartum hemorrhage was responsible for approximately half of severe maternal morbidity. Multiple patient factors were found to be independently associated with severe maternal morbidity and were used to develop a predictive model with an area under the receiver operating characteristic curve of 0.80. CONCLUSION: Severe maternal morbidity occurs in approximately 2.9 per 1,000 births, is most commonly the result of postpartum hemorrhage, and occurs more commonly in association with several identifiable patient characteristics. LEVEL OF EVIDENCE: : II.

Influenza-like illness in hospitalized pregnant and postpartum women during the 2009-2010 H1N1 pandemic.

OBJECTIVE: To estimate characteristics and outcomes of pregnant and immediately postpartum women hospitalized with influenza-like illness during the 2009-2010 influenza pandemic and the factors associated with more severe illness. METHODS: An observational cohort in 28 hospitals of pregnant and postpartum (within 2 weeks of delivery) women hospitalized with influenza-like illness. Influenza-like illness was defined as clinical suspicion of influenza and either meeting the Centers for Disease Control and Prevention definition of influenza-like illness (fever 100.0°F or higher, cough, sore throat) or a positive influenza test. RESULTS: Of 356 women meeting eligibility criteria, 35 (9.8%) were admitted to the intensive care unit (ICU) and four (1.1%) died. Two hundred eighteen women (61.2%) were in the third trimester and 10 (2.8%) were postpartum. More than half (55.3%) were admitted in October and 25.0% in November with rapidly decreasing numbers thereafter. Antiviral therapy was administered to 10.1% of the women before hospitalization and to 88.5% during hospitalization. Factors associated with an increased likelihood of ICU admission included cigarette smoking (29.4% compared with 13.4%; odds ratio [OR] 2.77, 95% confidence interval [CI] 1.19-6.45) and chronic hypertension (17.1% compared with 3.1%; OR 6.86, 95% CI 2.19-21.51). Antiviral treatment within 2 days of symptom onset decreased the likelihood of ICU admission (31.4% compared with 56.6%, OR 0.36, 95% CI 0.16-0.77). CONCLUSION: Comorbidities, including chronic hypertension and smoking in pregnancy, increase the likelihood of ICU admission in influenza-like illness hospitalizations, whereas early antiviral treatment may reduce its frequency. LEVEL OF EVIDENCE: II.

Does C-reactive protein predict recurrent preeclampsia?

OBJECTIVE: Evaluate association of the inflammatory marker C-reactive protein with recurrent preeclampsia. METHODS: Serum samples collected longitudinally in women with previous preeclampsia from the Maternal-Fetal Medicine Units Network trial of aspirin to prevent preeclampsia were assayed for CRP. RESULTS: Of 255 women studied, 50 developed recurrence. Baseline C-reactive protein concentration was similar between women who did and did not recur. After adjusting for confounders, neither elevated baseline C-reactive protein nor its change over gestation was associated with recurrence. CONCLUSION: In this group of women with previous preeclampsia, neither baseline C-reactive protein concentration nor change in concentration over gestation was associated with recurrent preeclampsia.

Perinatal outcomes in women with preterm rupture of membranes between 24 and 32 weeks of gestation and a history of vaginal bleeding.

OBJECTIVE: The purpose of this study was to compare perinatal outcomes among women with conservatively treated preterm premature rupture of membranes at 24 to 32 weeks of gestation in the presence or absence of vaginal bleeding. STUDY DESIGN: This is a secondary analysis of 581 women with and without vaginal bleeding within 1 week of admission with preterm premature rupture of membranes at 24 to 32 weeks of gestation who were enrolled in a multicenter trial of antibiotic therapy during conservative treatment. The main outcome was latency to delivery. Other outcome variables included clinical abruptio placentae, amnionitis, perinatal death, severe intraventricular hemorrhage, and respiratory distress syndrome. RESULTS: Outcome data were available for 581 patients (n=50 with bleeding). Latency to delivery was not affected by the presence or absence of bleeding. In general, a history of bleeding was associated with higher frequencies of subsequently diagnosed abruptio placentae (12% vs 3.5%; P=.01), perinatal death (16% vs 4.9%; P=.006), intraventricular hemorrhage (14.3% vs 5.9%; P=.03), and respiratory distress syndrome (69.4% vs 40.4%; P<.0001), when compared with those women with nonbleeding events. Women with bleeding were less likely to be black (42% vs 60%; P=.002) and had a lower mean gestational age at preterm premature rupture of membranes (27.6 vs 28.5 weeks; P=.02) when compared with white, Hispanic, and other. After an adjustment of data was made for potentially confounding factors, women with recent bleeding were more likely to be diagnosed with abruptio placentae at delivery (odds ratio, 2.8; 95% CI, 1.03-7.8; P=.04), and their infants were more likely to have respiratory distress syndrome (odds ratio, 3.1; 95% CI, 1.5-6.6; P=.004). CONCLUSION: Vaginal bleeding before preterm premature rupture of membranes is associated with increased rates of neonatal respiratory distress syndrome and abruptio placentae, but not with reduced latency to delivery.

The preterm prediction study: elevated cervical ferritin levels at 22 to 24 weeks of gestation are associated with spontaneous preterm delivery in asymptomatic women.

OBJECTIVE: Low serum ferritin levels correlate with low iron stores, whereas high levels are associated with an acute-phase reaction. Our objective was to determine whether elevated levels of ferritin in the genital tract may be a potent marker to identify patients at risk for spontaneous preterm delivery. STUDY DESIGN: We performed a nested case-control study involving 182 women who had spontaneous preterm delivery and 182 term control subjects matched for race, parity, and recruitment center, and selected from 2929 women enrolled in the Preterm Prediction Study of the National Institute of Child Health and Development Maternal-Fetal Medicine Units Network. Cervical fluid ferritin was measured by use of radioimmunoassay. RESULTS: Cervical ferritin levels were significantly higher in women who subsequently had spontaneous early preterm delivery (<32 weeks, mean +/- SD, 37.7 +/- 31.1 vs 21.5 +/- 24.1 ng/mL, P =.002; and <35 weeks, 43.2 +/- 62.7 vs 28.2 +/- 36.7 ng/mL, P =.004) than in term controls. A cervical ferritin of >75th percentile in the controls (>35.5 ng/mL) was found in 52.9% (9/17) of the women delivered <29 weeks vs 17.7% (3/17) of the controls (odds ratio [OR] 5.3 [95% CI 1.1-25.2]) and in 43.5% (20/46) of the women delivered <32 weeks versus 10.9% (5/46) of the controls (OR 6.3, 95% CI 2.1-18.9). Cervical ferritin levels had a weaker association with spontaneous preterm delivery <35 weeks (OR 2.8 [95% CI 1.5-5.1]) and <37 weeks (OR 1.6, 95% CI 1.0-2.5]). Cervical ferritin levels correlated significantly with cervical lactoferrin, interleukin-6 (IL-6), and defensin levels. CONCLUSIONS: Elevated cervical ferritin levels at 22 to 24 weeks of gestation in asymptomatic women are associated with subsequent spontaneous preterm birth. The strong correlation of cervical ferritin with other inflammatory markers provides support for the hypothesis of infection as a mediator of preterm delivery.

Sexual intercourse association with asymptomatic bacterial vaginosis and Trichomonas vaginalis treatment in relationship to preterm birth.

OBJECTIVE: The purpose of this study was to determine whether sexual intercourse was associated with the treatment efficacy or the incidence of preterm birth in two large randomized trials in which metronidazole treatment of bacterial vaginosis or Trichomonas vaginalis did not reduce preterm birth. STUDY DESIGN: Secondary analysis of two multicenter, double-blind, placebo-controlled trials in which women with asymptomatic bacterial vaginosis on Gram stain or asymptomatic T vaginalis on culture were randomized at 16 to 23 weeks of gestation to metronidazole or placebo. In both studies, women took 2 g of metronidazole or placebo in the presence of a nurse (first dose) and were given a second dose to take 48 hours later. This regimen was repeated (third and fourth doses) at 24 to 29 weeks. At the time of the third dose, bacterial vaginosis and T vaginalis specimens were collected again. Patients who were randomly selected to receive metronidazole were analyzed for bacterial vaginosis and T vaginalis at 24 to 29 weeks and for preterm birth of <37 weeks of gestation, according to intercourse between first and second doses and between the second and third doses. Continuous variables were compared with the use of the Wilcoxon rank-sum test; categoric variables were compared with the use of the chi(2 ) test, Fisher exact test, or the Mantel-Haenzel test of trend. RESULTS: Sexual intercourse between the first and second doses or between the second and third doses did not influence the incidence of bacterial vaginosis (18% vs 24%; relative risk, 0.7; 95% CI, 0.5-1.1; and 23% vs 20%; relative risk, 1.2; 95% CI, 0.9-1.6, respectively) or T vaginalis (4% vs 8%; relative risk, 0.5; 95% CI, 0.1-3.6; and 5% vs 10%; relative risk, 0.5; 95% CI, 0.2-1.1; respectively) at 24 to 29 weeks of gestation compared with no intercourse. In the T vaginalis trial, sexual intercourse between the first and second doses or between the second and third doses did not influence the incidence of preterm birth (13% vs 17%; relative risk, 0.8; 95% CI, 0.3-2.1; and 16% vs 17%; relative risk, 1.0; 95% CI, 0.6-1.6; respectively) compared with no intercourse. In the bacterial vaginosis trial, although sexual intercourse between the first and second doses did not influence the incidence of preterm birth (11% vs 12%; relative risk, 0.9; 95 % CI, 0.6-1.5), sexual intercourse between the second and third doses was associated with a reduction in the incidence of preterm birth (10% vs 16%; relative risk, 0.6; 95% CI, 0.4-0.9) compared with no intercourse. CONCLUSION: Sexual intercourse was associated with neither the efficacy of metronidazole treatment of bacterial vaginosis or T vaginalis nor with the incidence of preterm birth. In the bacterial vaginosis study, intercourse between the second and third doses had a negative association with preterm birth.