Predicting Placenta Accreta Spectrum: Validation of the Placenta Accreta Index.

OBJECTIVES: The placenta accreta spectrum (PAS) incidence has risen substantially over the past century, paralleling a rise in cesarean delivery (CD) rates. Prenatal diagnosis of PAS improves maternal outcomes. The Placenta Accreta Index (PAI) is a standardized approach to prenatal diagnosis of PAS incorporating clinical risk and ultrasound (US) findings suggestive of placental invasion. We sought to validate the PAI for prediction of PAS in pregnancies with prior CD. METHODS: This work was a retrospective cohort study of pregnancies with 1 or more prior CDs that received a US diagnosis of placenta previa or low-lying placenta in the third trimester. Images of third-trimester US with a complete placental evaluation were read by 2 blinded physicians, and the PAI was applied. Surgical outcomes and pathologic findings were reviewed. Placenta accreta spectrum was diagnosed if clinical evidence of invasion was seen at time of delivery or if any placental invasion was identified histologically. International Federation of Gynecology and Obstetrics criteria were used. RESULTS: A total of 194 women met inclusion criteria. Cesarean hysterectomy was performed in 92 (47%), CD in 97 (50%), and vaginal delivery in 5 (3%). Of those who underwent hysterectomy, PAS was histologically confirmed in 79 (85%) pregnancies. Of the remaining 13 who underwent hysterectomy, all met International Federation of Gynecology and Obstetrics grade 1 clinical criteria for PAS. With a threshold of greater than 4, the PAI has a sensitivity of 87%, specificity of 77%, positive predictive value of 72%, and negative predictive value of 90% for PAS diagnosis. CONCLUSIONS: Contemporaneous application of the PAI, a standardized approach to US diagnosis, is useful in the prenatal prediction of PAS.

Prospective First-Trimester Ultrasound Imaging of Low Implantation and Placenta Accreta Spectrum.

OBJECTIVES: To prospectively evaluate low implantation of the gestational sac and other first-trimester ultrasound (US) parameters for prediction of placenta accreta spectrum (PAS). METHODS: Women with a diagnosis of low implantation on clinically indicated first-trimester US underwent a transvaginal US examination at 10 to 13 weeks' gestation to assess the trophoblast location, anechoic areas, bridging vessels, and smallest myometrial thickness (SMT). The placental location was evaluated in the second trimester, and serial US examinations were performed in cases of low placentation. Placenta accreta spectrum was based on clinical findings and confirmed by histologic results. RESULTS: Of 68 women, 40 (59%) had prior cesarean delivery (CD). Hysterectomy was performed in 8, all with prior CD. Of these, 7 (88%) had US suspicion of PAS. In 16 with prior CD and basalis overlying the internal os, 9 (56%) had second-trimester placenta previa, and 7 of 9 (78%) underwent hysterectomy with pathologic confirmation of PAS. Of 28 without prior CD, there were no cases of persistent low placentation in the third trimester regardless of the trophoblast location. Ultrasound parameters associated with PAS were a smaller distance from the inferior trophoblastic border to the external os, disruption of the bladder-serosal interface, bridging vessels, anechoic areas, and the SMT. In women with prior CD, use of the SMT in the sagittal plane yielded an area under the receiver operating characteristic curve of 0.96 (95% confidence interval, 0.91-1.00). CONCLUSIONS: First-trimester low implantation increases the risk of persistent placenta previa and PAS in women with prior CD. All parameters were associated with PAS, the most predictive being the SMT.

Perinatal outcomes associated with abnormal cardiac remodeling in women with treated chronic hypertension.

BACKGROUND: Adverse maternal outcomes associated with chronic hypertension include accelerated hypertension and resultant target organ damage. One example is long-standing hypertension leading to maternal cardiac dysfunction. Our group has previously identified that features of such injury manifest as cardiac remodeling with left ventricular hypertrophy. Moreover, these features of cardiac remodeling identified in women with chronic hypertension during pregnancy were associated with adverse perinatal outcomes. Recent definitions of maternal cardiac remodeling using echocardiography have been expanded to include measurements of wall thickness. We hypothesized that these new features characterizing cardiac remodeling in women with chronic hypertension may also be associated with adverse perinatal outcomes. OBJECTIVE: There were 3 aims in this study of women with treated chronic hypertension during pregnancy: to (1) apply the updated definitions of maternal cardiac remodeling; (2) elucidate whether these features of cardiac remodeling were associated with adverse perinatal outcomes; and (3) determine which, if any, of the newly defined cardiac remodeling strata were most damaging when compared to women with normal cardiac geometry. STUDY DESIGN: This was a retrospective study of women with treated chronic hypertension during pregnancy delivered from January 2009 through January 2016. Cardiac remodeling was categorized by left ventricular mass index and relative wall thickness into 4 groups determined using the 2015 American Society of Echocardiography guidelines: normal geometry, concentric remodeling, eccentric hypertrophy, and concentric hypertrophy. Perinatal outcomes were analyzed according to each category of cardiac remodeling compared with outcomes in women with normal geometry. RESULTS: A total of 314 women with treated chronic hypertension underwent echocardiography at a mean gestational age of 17.9 weeks. There were no differences between maternal age (P = .896), habitus (P = .36), or duration of chronic hypertension (P = .212) among the 4 groups. Abnormal cardiac remodeling was found in 51% and was significantly associated with increased rates of superimposed preeclampsia (P = .015), preterm birth (P < .001), and neonatal intensive care admission (P = .003). These outcomes reached the greatest significance when comparisons were made between eccentric hypertrophy and normal geometry. CONCLUSION: Using current American Society of Echocardiography guidelines, 51% of women with treated chronic hypertension during pregnancy have some degree of abnormal cardiac remodeling. Any suggestion of maternal cardiac remodeling, regardless of subtype, was associated with increased risks for superimposed preeclampsia and preterm birth with its resultant perinatal sequelae. Eccentric ventricular hypertrophy, previously thought to mimic exercise physiology, appears to be the most associated with adverse perinatal outcomes. Despite evidence of cardiac remodeling, ejection fraction was preserved.

Frequency and consequences of ventricular hypertrophy in pregnant women with treated chronic hypertension.

BACKGROUND: Ventricular hypertrophy is a known sequela of long-standing chronic hypertension with associated morbidity and mortality. OBJECTIVE: We sought to assess the frequency and importance of left ventricular hypertrophy in gravidas treated for chronic hypertension during pregnancy. STUDY DESIGN: This was a retrospective study of pregnant women with chronic hypertension who were delivered at our hospital from January 2009 through February 2015. All women who were given antihypertensive therapy underwent maternal echocardiography and were managed in a dedicated, high-risk prenatal clinic. Left ventricular hypertrophy was defined using the criteria of the American Society of Echocardiography as left ventricular mass indexed to maternal body surface area with a value of >95 g/m2. Maternal and infant outcomes were then analyzed according to the presence or absence of left ventricular hypertrophy. RESULTS: Of 253 women who underwent echocardiography, 48 (19%) met criteria for left ventricular hypertrophy. Women in this latter cohort were significantly more likely to be African American (P = .031), but there were no other demographic differences. More than 85% of the entire cohort had a body mass index >30 kg/m2 and a third of all women had class III obesity with a body mass index of >40 kg/m2. Importantly, duration of chronic hypertension (P = .248) and gestational age at time of echocardiography (P = .316) did not differ significantly between the groups. Left ventricular function was preserved in both groups as measured by left ventricular ejection fraction (P = .303). Those with ventricular hypertrophy were at greater risk to be delivered preterm (P = .001), to develop superimposed preeclampsia (P = .028), and to have an infant requiring intensive care (P = .023) when compared with women without ventricular hypertrophy. These findings persisted after adjustment for age, race, and parity. The gestational age at delivery according to measured left ventricular size was also examined and with increasing ventricular mass there was a significant association with the severity of preterm birth (P < .001). CONCLUSION: Left ventricular hypertrophy was identified in 1 in 5 women given antepartum treatment for chronic hypertension. Further analysis showed that these women were at significantly greater risk for superimposed preeclampsia and its attendant perinatal sequelae of preterm birth.

Cervical Length in Patients at Risk for Placenta Accreta.

OBJECTIVES: To evaluate cervical length measurements in women with placenta accreta compared to women with a nonadherent low-lying placenta or placenta previa and evaluate this relationship in terms of vaginal bleeding, preterm labor, and preterm birth. METHODS: We conducted a retrospective cohort study between 1997 and 2011 of gravidas with more than 1 prior cesarean delivery who had a transvaginal ultrasound examination between 24 and 34 weeks for a low-lying placenta or placenta previa. Cervical length was measured from archived images in accordance with national guidelines by a single investigator, who was blinded to outcomes and ultrasound reports. The diagnosis of placental accreta was based on histologic confirmation. For study purposes, preterm birth was defined as less than 36 weeks, and cervical lengths of 3 cm or less were considered short. Standard statistical analyses were used. RESULTS: A total of 125 patients met inclusion criteria. The cohort was divided into patients with (n = 43 [34%]) and without (n = 82 [66%]) placenta accreta and stratified by gestational age at the ultrasound examinations. Women with placenta accreta had shorter cervical length measurements during their 32- to 34-week ultrasound examinations (mean ± SD, 3.23 ± 0.98 versus 3.95 ± 1.0 cm; P < .01) and were more likely to have a short cervix of 3 cm or less (P = .001). However, these findings did not correlate with the degree of invasion (P = .3), or higher rates of vaginal bleeding and preterm labor (P = .19) resulting in preterm birth before 36 weeks (P = .64). CONCLUSIONS: Women with placenta accreta had shorter cervical lengths at 32 to 34 weeks than women with a nonadherent low-lying placenta or placenta previa, but this finding did not correlate with a higher risk of vaginal bleeding or preterm labor resulting in preterm birth before 36 weeks.

Sonographic Findings of Morbidly Adherent Placenta in the First Trimester.

OBJECTIVES: The purpose of this study was to evaluate the association between first-trimester sonographic findings and morbidly adherent placenta at delivery. METHODS: We conducted a retrospective review of all first-trimester sonographic examinations from pregnancies that underwent third-trimester sonography for placenta previa or low-lying placenta between September 1997 and October 2011. Only women with a prior cesarean delivery were included. Transabdominal and transvaginal images from these first-trimester studies were reviewed for the following sonographic parameters: distance from the inferior border of the gestational sac to the external cervical os, location of the decidua basalis, presence of anechoic areas, uterine-bladder interface irregularity, and smallest anterior myometrial thickness. Morbidly adherent placentation was confirmed on histologic examination of hysterectomy specimens. Statistical methods included univariate and multivariate analyses. RESULTS: Thirty-nine patients met inclusion criteria, of whom 14 (36%) had confirmed placental invasion. The number of prior cesarean deliveries was significantly associated with placental invasion (P < .0001). The only first-trimester sonographic finding associated with invasion was the smallest anterior myometrial thickness measured in the sagittal plane (P < .02). Multivariate analysis based on these two variables yielded an area under the receiver operating characteristic curve of 0.94 (95% confidence interval, 0.87-1.00) and significantly improved the prediction of placental invasion compared to using the number of prior cesarean deliveries alone. CONCLUSIONS: In women with persistent placenta previa or low-lying placenta and prior cesarean delivery, the smallest anterior myometrial thickness on first-trimester sonography significantly improved detection of morbidly adherent placenta.

Blood Pressure Profiles Across Pregnancy in Women with Chronic Hypertension.

Objective To examine blood pressure patterns across pregnancy in women with treated chronic hypertension according to the occurrence of severe preeclampsia, growth restriction, and preterm birth <34 weeks. Methods This retrospective descriptive case study included only pregnant women receiving antihypertensive therapy. Using a random effects model, mean arterial pressures were plotted across gestation for women with and without preeclampsia, fetal growth restriction, and preterm birth <34 weeks with differences analyzed for each curve. Results Between January 2002 and December 2014, 447 women met inclusion criteria. Of these women, 65% developed severe preeclampsia, 24% delivered an infant weighing <10th percentile, and 15% had a preterm birth <34 weeks. Women diagnosed with either preeclampsia (23.3 vs 26.4 weeks; mean difference, 3.1 weeks; 95% confidence interval [CI], 2.3-4.3), fetal growth restriction (23.5 vs 24.9 weeks; mean difference, 1.4 weeks; 95% CI, 0.2-2.6), or preterm birth (19.8 vs 24.9 weeks; mean difference, 5.1 weeks; 95% CI, 3.7-6.9) reached a blood pressure nadir at a significantly earlier gestational age than those who did not. Conclusion For pregnant women with treated chronic hypertension, blood pressure patterns differ significantly in those who develop severe preeclampsia, fetal growth restriction, and preterm birth <34 weeks.

Ultrasound predictors of placental invasion: the Placenta Accreta Index.

OBJECTIVE: We sought to apply a standardized evaluation of ultrasound parameters for the prediction of placental invasion in a high-risk population. STUDY DESIGN: This was a retrospective review of gravidas with ≥1 prior cesarean delivery who received an ultrasound diagnosis of placenta previa or low-lying placenta in the third trimester at our institution from 1997 through 2011. Sonographic images were reviewed by an investigator blinded to pregnancy outcome and sonography reports. Parameters assessed included loss of retroplacental clear zone, irregularity and width of uterine-bladder interface, smallest myometrial thickness, presence of lacunar spaces, and bridging vessels. Diagnosis of placental invasion was based on histologic confirmation. Statistical analyses were performed using linear logistic regression and multiparametric analyses to generate a predictive equation evaluated using a receiver operating characteristic curve. RESULTS: Of 184 gravidas who met inclusion criteria, 54 (29%) had invasion confirmed on hysterectomy specimen. All sonographic parameters were associated with placental invasion (P < .001). Constructing a receiver operating characteristic curve, the combination of smallest sagittal myometrial thickness, lacunae, and bridging vessels, in addition to number of cesarean deliveries and placental location, yielded an area under the curve of 0.87 (95% confidence interval, 0.80-0.95). Using logistic regression, a predictive equation was generated, termed the "Placenta Accreta Index." Each parameter was weighted to create a 9-point scale in which a score of 0-9 provided a probability of invasion that ranged from 2-96%, respectively. CONCLUSION: Assignment of the Placenta Accreta Index may be helpful in predicting individual patient risk for morbidly adherent placenta.

Benefit of interpregnancy HIV viral load suppression on subsequent maternal and infant outcomes.

OBJECTIVE: The objective of the study was to determine whether interpregnancy human immunodeficiency virus (HIV) viral load suppression affects outcomes in subsequent pregnancies. STUDY DESIGN: This is a retrospective review of all women who delivered 2 consecutive pregnancies while diagnosed with HIV from Jan. 1, 1984, until Jan. 1, 2012. Medical records were reviewed for maternal, infant, and delivery data. Pregnancies were divided into index and subsequent pregnancy and analyzed for outcomes. RESULTS: During the study period, 172 HIV-infected women who delivered 2 pregnancies at our institution were identified. There was no difference in median HIV viral load at presentation or delivery between the index and subsequent pregnancies. During the subsequent pregnancy, more women presented on antiretroviral therapy (ART) and more often remained compliant with ART; however, there was no difference in vertical transmission risk between the pregnancies. Of those with a viral load less than 1000 copies/mL at the end of their index pregnancy (n = 103), 57 (55%) presented for their subsequent pregnancy with a viral load still less than 1000 copies/mL. Those women who maintained the viral load suppression between pregnancies were more likely to present for their subsequent pregnancy on ART, maintained a greater viral load suppression and CD4 counts during the pregnancy, and had fewer vertical transmissions compared with those who presented with higher viral loads in their subsequent pregnancy (0% vs 9%, P = .02). CONCLUSION: Maintaining an HIV viral load suppression between pregnancies is associated with improved HIV disease status at delivery in subsequent pregnancies. Interpregnancy HIV viral load suppression is associated with less vertical transmission, emphasizing the importance of maintaining HIV disease control between pregnancies.

Biometric sonographic findings of abnormally adherent trophoblastic implantations on cesarean delivery scars.

OBJECTIVES: The purpose of this study was to review first-trimester transvaginal sonograms of patients with cervicoisthmic implantations and prior cesarean deliveries to determine whether sonographic biometric measurements can distinguish between abnormally adherent trophoblastic implantations and normally implanted pregnancies. METHODS: Our database was reviewed from October 2006 through December 2011 for patients with first-trimester sonographic diagnoses of cervicoisthmic implantations and previous cesarean deliveries. Biometric measurements of the smallest distance from the anterior trophoblastic border to the uterine serosa were performed on transvaginal sagittal images of the uterus. Outcomes were classified into 5 categories: cesarean scar pregnancy, placental invasion (accreta/increta/percreta), previa without invasion, spontaneous abortion, and delivered intrauterine pregnancy. Statistical methods included analysis of variance with the Tukey range test and Student t test. RESULTS: Of 77 studies, outcome data were available for 56 patients. The mean gestational age was 8.8 weeks (minimum, 2.0 weeks; maximum, 14.9 weeks). The anterior trophoblastic border distances from the uterine serosa were significantly smaller in cesarean scar pregnancies (mean, 1.6 mm; SD, 0.6 mm) and placental invasion pregnancies (mean, 2.2 mm; SD, 1.0 mm) than the normally implanted groups (mean, 7.9 mm, SD, 3.3 mm; P < .0001). CONCLUSIONS: Smaller trophoblastic border distances to the anterior uterine serosa are seen in abnormally adherent trophoblastic implantations, and these distances distinguish them from other pregnancy outcomes.

Nifedipine for Acute Tocolysis of Preterm Labor: A Placebo-Controlled Randomized Trial.

OBJECTIVE: To evaluate the effectiveness of acute nifedipine tocolysis in preventing preterm birth in women in preterm labor. METHOD: This was a randomized, double-blind, placebo-controlled trial of nifedipine in women with a singleton pregnancy between 28 0/7 and 33 6/7 weeks of gestation who were admitted with uterine activity, intact membranes, and cervical dilatation from 2 to 4 cm. Women were randomized to receive nifedipine 20 mg or placebo orally, followed by a repeat dose after 90 minutes if contractions persisted. The study drug was continued every 4 hours to complete a 48-hour regimen. The primary outcome was birth before 37 weeks of gestation. A total of 150 women were necessary to detect a one-third reduction in this outcome. After treating 88 patients, a preplanned interim analysis of blinded outcomes by the Data Safety Monitoring Committee recommended discontinuation of the trial due to futility. RESULTS: A total of 90 women were enrolled between May 2014 and November 2017. After two women withdrew, 88 were analyzed: 46 in the nifedipine group and 42 in the placebo group. There was no significant difference in the primary outcome of delivery before 37 weeks of gestation in the nifedipine group compared with the placebo group (52% vs 48%, relative risk [RR] 1.1, 95% CI 0.7-1.7), nor in the secondary outcome of delivery at least 48 hours from randomization (78% vs 71%, respectively, RR 1.1, 95% CI 0.9-1.4). There were also no significant differences between groups in neonatal outcomes. CONCLUSION: Acute tocolysis of preterm labor with nifedipine did not affect preterm birth rates, delivery within 48 hours, or neonatal outcomes. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT02132533.

The impact of baseline proteinuria in pregnant women with pregestational diabetes mellitus.

BACKGROUND: The incidence of diabetes in pregnancy has increased dramatically with the rising rates of obesity. Because there are a number of recognized adverse maternal and fetal outcomes associated with diabetes, there have been several attempts to classify this disorder for perinatal risk stratification. One of the first classification systems for pregnancy was developed by White nearly 70 years ago. More recently, efforts to stratify diabetic disease severity according to vasculopathy have been adopted. Regardless of classification system, vasculopathy-associated effects have been associated with worsening pregnancy outcomes. Defining vasculopathy within an organ system, however, has not been consistent. For example, definitions of diabetic kidney disease differ from the previously used threshold of ≥500 mg/d by White for pregnancy to varying thresholds of albuminuria by the American Diabetes Association. OBJECTIVE: To evaluate a proteinuria threshold that was a relevant determinant of perinatal risk in a cohort of women with type 2 diabetes. MATERIALS AND METHODS: This was a retrospective cohort study of women with pregestational diabetes delivered of nonanomalous, singleton, liveborn infants. All women were assessed for baseline maternal disease burden with a 24-hour proteinuria quantification performed before 20 weeks' gestation. Women with <500 mg/d on 24-hour urine collections were included. Perinatal outcomes were analyzed according to the following protein excretion values: 50-100, 101-200, 201-300, and 301-499 mg/d. Based on trends noted in these results and using the prior definition of the American Diabetes Association of 300 mg/d of albumin for diabetic kidney disease, women were then analyzed according to 24-hour urine collections of ≤300 or >300 mg/d. RESULTS: Between 2009 and 2016, a total of 594 women with pregestational diabetes were found to meet study criteria. When analyzed according to protein excretion values 50-100, 101-200, 201-300, and 301-499 mg/d, there were no differences in maternal demographics. The rate of preeclampsia with severe features (P for trend = .02), preterm birth at <37 weeks (P for trend <.001), and birthweight <10th percentile (P for trend = .02) were significantly associated with increasing proteinuria excretion, with the highest rates in the >300 mg/d group. Perinatal outcomes were then examined in the context of 24-hour urine protein excretion values of ≤300 or >300 mg/d, with no differences in maternal demographics. Protein excretion values >300 mg/d were significantly associated with preterm birth <37 weeks (P = .003), preeclampsia with severe features (P = .002), and birthweight <10th percentile (P = .048). CONCLUSION: White's classification in 1949 was developed to stratify perinatal risks based on maternal disease burden, and it was found that urinary protein excretion of >500 mg/d was associated with adverse pregnancy outcomes. In a contemporary cohort of pregnant women, proteinuria >300 mg/d was associated with preterm birth, preeclampsia with severe features, and birthweight <10th percentile.

Subclinical hyperthyroidism and pregnancy outcomes.

OBJECTIVE: Subclinical hyperthyroidism has long-term sequelae that include osteoporosis, cardiovascular morbidity, and progression to overt thyrotoxicosis or thyroid failure. The objective of this study was to evaluate pregnancy outcomes in women with suppressed thyroid-stimulating hormone (TSH) and normal free thyroxine (fT(4)) levels. METHODS: All women who presented to Parkland Hospital for prenatal care between November 1, 2000, and April 14, 2003, underwent thyroid screening by chemiluminescent TSH assay. Women with TSH values at or below the 2.5th percentile for gestational age and whose serum fT(4) levels were 1.75 ng/dL or less were identified to have subclinical hyperthyroidism. Those women screened and delivered of a singleton infant weighing 500 g or more were analyzed. Pregnancy outcomes in women identified with subclinical hyperthyroidism were compared with those in women whose TSH values were between the 5th and 95th percentiles. RESULTS: A total of 25,765 women underwent thyroid screening and were delivered of singleton infants. Of these, 433 (1.7%) were considered to have subclinical hyperthyroidism, which occurred more frequently in African-American and/or parous women. Pregnancies in women with subclinical hyperthyroidism were less likely to be complicated by hypertension (adjusted odds ratio 0.66, 95% confidence interval 0.44-0.98). All other pregnancy complications and perinatal morbidity or mortality were not increased in women with subclinical hyperthyroidism. CONCLUSION: Subclinical hyperthyroidism is not associated with adverse pregnancy outcomes. Our results indicate that identification of subclinical hyperthyroidism and treatment during pregnancy is unwarranted. LEVEL OF EVIDENCE: II-2.

Association of Baseline Proteinuria and Adverse Outcomes in Pregnant Women With Treated Chronic Hypertension.

OBJECTIVE: To assess the importance of baseline proteinuria in women treated for chronic hypertension during pregnancy. METHODS: This retrospective cohort study included women with chronic hypertension who received antihypertensive therapy in the first half of pregnancy and completed urine protein quantification before 20 weeks of gestation. Maternal and neonatal outcomes were analyzed according to the presence or absence of baseline proteinuria, defined as 300 mg or greater per 24 hours identified before 20 weeks of gestation. Frequencies of superimposed preeclampsia, preterm birth, and small-for-gestational-age neonates were further evaluated according to stratified urine protein excretion levels from less than 50 mg to greater than 1,000 mg/24 hours. RESULTS: Between January 2002 and December 2014, a total of 447 women met inclusion criteria. Of these, 56 (13%) had baseline proteinuria. Women with baseline proteinuria were statistically significantly more likely to develop superimposed preeclampsia (79% compared with 49%), deliver preterm (18% compared with 6% 30 weeks of gestation or less, 34% compared with 17% 34 weeks of gestation or less, and 48% compared with 26% less than 37 weeks of gestation), and deliver an small-for-gestational-age neonate (41% compared with 22% less than the 10th percentile, 20% compared with 9% less than the third percentile) when compared with women who did not have proteinuria (all P<.05). Furthermore, the rates of superimposed preeclampsia and small for gestational age were significantly increased as 24-hour protein excretion levels increased across stratified levels (P for trend .002 and .015, respectively). When proteinuria levels less than 300 mg/d were analyzed separately, a significant association was observed for rates of superimposed preeclampsia and preterm birth. CONCLUSION: In pregnant women with treated chronic hypertension, baseline proteinuria was significantly associated with increased rates of preeclampsia, preterm birth, and growth restriction-even at proteinuria values previously considered to be within normal range (less than 300 mg/d).

Thyroid-stimulating hormone in singleton and twin pregnancy: importance of gestational age-specific reference ranges.

OBJECTIVE: To estimate a normal reference range for thyroid-stimulating hormone (TSH) at each point in gestation in singleton and twin pregnancies. METHODS: All women enrolling for prenatal care from December 2000 through November 2001 underwent prospective TSH screening at their first visit. Separate nomograms were constructed for singleton and twin pregnancies using regression analysis. Values were converted to multiples of the median (MoM) for singleton pregnancies at each week of gestation. RESULTS: Thyroid-stimulating hormone was evaluated in 13,599 singleton and 132 twin pregnancies. Thyroid-stimulating hormone decreased significantly during the first trimester, and the decrease was greater in twins (both P < .001). Had a nonpregnant reference (0.4-4.0 mU/L) been used rather than our nomogram, 28% of 342 singletons with TSH greater than 2 standard deviations above the mean would not have been identified. For singleton first-trimester pregnancies, the approximate upper limit of normal TSH was 4.0 MoM, and for twins, 3.5 MoM. Thereafter, the approximate upper limit was 2.5 MoM for singleton and twin pregnancies. CONCLUSION: If thyroid testing is performed during pregnancy, nomograms that adjust for fetal number and gestational age may greatly improve disease detection. Values expressed as multiples of the median may facilitate comparisons across different laboratories and populations.

Subclinical hypothyroidism and pregnancy outcomes.

BACKGROUND: Clinical thyroid dysfunction has been associated with pregnancy complications such as hypertension, preterm birth, low birth weight, placental abruption, and fetal death. The relationship between subclinical hypothyroidism and pregnancy outcomes has not been well studied. We undertook this prospective thyroid screening study to evaluate pregnancy outcomes in women with elevated thyrotropin (thyroid-stimulating hormone, TSH) and normal free thyroxine levels. METHODS: All women who presented to Parkland Hospital for prenatal care between November 1, 2000, and April 14, 2003, had thyroid screening using a chemiluminescent TSH assay. Women with TSH values at or above the 97.5th percentile for gestational age at screening and with free thyroxine more than 0.680 ng/dL were retrospectively identified with subclinical hypothyroidism. Pregnancy outcomes were compared with those in pregnant women with normal TSH values between the 5th and 95th percentiles. RESULTS: A total of 25,756 women underwent thyroid screening and were delivered of a singleton infant. There were 17,298 (67%) women enrolled for prenatal care at 20 weeks of gestation or less, and 404 (2.3%) of these were considered to have subclinical hypothyroidism. Pregnancies in women with subclinical hypothyroidism were 3 times more likely to be complicated by placental abruption (relative risk 3.0, 95% confidence interval 1.1-8.2). Preterm birth, defined as delivery at or before 34 weeks of gestation, was almost 2-fold higher in women with subclinical hypothyroidism (relative risk, 1.8, 95% confidence interval 1.1-2.9). CONCLUSION: We speculate that the previously reported reduction in intelligence quotient of offspring of women with subclinical hypothyroidism may be related to the effects of prematurity. LEVEL OF EVIDENCE: II-2.

Placenta accreta and vaginal bleeding according to gestational age at delivery.

OBJECTIVE: To evaluate the incidence of vaginal bleeding in women with placenta accreta according to gestational age at delivery. METHODS: This is a retrospective cohort study of women with prior cesarean delivery and persistent placenta previa delivered at our institution between December 1997 and December 2011. Diagnosis of invasion was based on hysterectomy performed for an abnormally adherent placenta with histologic confirmation. Suspicion for invasion was based on the impression of the attending physician at the time of ultrasonography. Records were reviewed to identify indication for delivery and estimated blood loss. Statistical analyses were performed using Student's t test, χ2 test, and Mantel-Haenszel and Jonckheere-Terpstra tests for trend. RESULTS: Of 216 women with prior cesarean delivery and persistent previa, 65 (30%) required cesarean hysterectomy and had histologic confirmation of invasion. Urgent delivery for bleeding was performed in 20% of these pregnancies (13/65). Delivery for bleeding decreased significantly with advancing gestation (P=.001). In our series, 71% with accreta were delivered at 36 weeks of gestation or greater with delivery for bleeding in five (11%), and estimated blood loss was not increased in these pregnancies. Of 79 women with ultrasonographic suspicion for accreta, the incidence of vaginal bleeding prompting urgent delivery also decreased with advancing gestation (P<.001). CONCLUSION: Likelihood of vaginal bleeding necessitating delivery declined with advancing gestation in pregnancies with placenta accreta as did blood loss. Most were delivered at 36 weeks of gestation or greater, nearly 90% in the absence of bleeding complications. Thus, although preterm delivery is an important consideration when placenta accreta is suspected, our findings support individualizing delivery planning.

Vaginal birth after cesarean delivery: views from the private practitioner.

This survey was conducted to assess physician opinion regarding vaginal birth after cesarean delivery (VBAC) and to examine how physician and hospital characteristics influence the private obstetrical provider's decision to offer or not to offer trial of labor after cesarean delivery. A confidential postal survey of private practicing obstetricians in the Dallas-Ft. Worth Region (n = 774) of North Texas. Of 774 obstetrician-gynecologists, 458 completed and returned the survey for a response rate of 59%. The survey revealed that 52% of respondents offer VBAC to their patients and indicated that the most common reasons for declining use or discontinuation of VBAC were maternal-fetal safety concerns associated with uterine rupture followed by medico-legal liability concerns. Factors associated with physicians not providing VBAC for their patients were physicians in obstetrical practice <10 years, a physician's previous involvement in the care of women with uterine rupture complicated by maternal or neonatal complications, and a physician's previous involvement in cesarean delivery-related medical malpractice litigation.