Placenta previa percreta with surrounding organ involvement: a proposal for management.

Placenta accreta spectrum encompasses cases where the placenta is morbidly adherent to the myometrium. Placenta percreta, the most severe form of placenta accreta spectrum (grade 3E), occurs when the placenta invades through the myometrium and possibly into surrounding structures next to the uterine corpus. Maternal morbidity of placenta percreta is high, including severe maternal morbidity in 82.1% and mortality in 1.4% in the recent nationwide U.S. statistics. Although cesarean hysterectomy is commonly performed for patients with placenta accreta spectrum, conservative management is becoming more popular because of reduced morbidity in select cases. Treatment of grade 3E disease involving the urinary bladder, uterine cervix, or parametria is surgically complicated due to the location of the invasive placenta deep in the maternal pelvis. Cesarean hysterectomy in this setting has the potential for catastrophic hemorrhage and significant damage to surrounding organs. We propose a step-by-step schema to evaluate cases of grade 3E disease and determine whether immediate hysterectomy or conservative management, including planned delayed hysterectomy, is the most appropriate treatment option. The approach includes evaluation in the antenatal period with ultrasound and magnetic resonance imaging to determine suspicion for placenta previa percreta with surrounding organ involvement, planned cesarean delivery with a multidisciplinary team including experienced pelvic surgeons such as a gynecologic oncologist, intra-operative assessment including gross surgical field exposure and examination, cystoscopy, and consideration of careful intra-operative transvaginal ultrasound to determine the extent of placental invasion into surrounding organs. This evaluation helps decide the safety of primary cesarean hysterectomy. If safely resectable, additional considerations include intra-operative use of uterine artery embolization combined with tranexamic acid injection in cases at high risk for pelvic hemorrhage and ureteral stent placement. Availability of resuscitative endovascular balloon occlusion of the aorta is ideal. If safe resection is concerned, conservative management including planned delayed hysterectomy at around 4 weeks from cesarean delivery in stable patients is recommended.

Gynecologic oncologists in surgery for placenta accreta spectrum: a survey for practice, experience, and interest.

OBJECTIVE: Surgery for placenta accreta spectrum is associated with significant maternal morbidity and mortality. The role of gynecologic oncologists in the surgical management of placenta accreta spectrum is currently under investigation. This study examined the practices, experiences, and interests of gynecologic oncologists in placenta accreta spectrum surgeries. METHODS: The intervention was an anonymous, cross-sectional, 20-question survey sent to 1084 members of the Society of Gynecologic Oncology in the USA. RESULTS: A total of 184 gynecologic oncologists responded to the survey (response rate 17.0%). Most participating gynecologic oncologists have been practicing for >10 years after fellowship (53.2%), practice in urban-teaching hospitals (84.8%) with delivery volumes ≥3000/year (54.3%), and have a multidisciplinary approach (82.5%). Three-quarters (78.7%) feel that the rate of placenta accreta spectrum is increasing over time. One-third (35.5%) perform ≥6 hysterectomies for placenta accreta spectrum yearly. Less than half (45.5%) practice conservative management. Approximately half are involved from the beginning of the case (49.7%) and perform the surgery in the main operating room (59.4%). Almost three-quarters (71.6%) have experienced surgical blood loss >5 L and one-third (36.6%) have experienced cases with blood loss >10 L. About half (50.3%) of participants are interested in placenta accreta spectrum surgery for future practice. Gynecologic oncologists engaging in a multidisciplinary approach are more likely to practice in an urban-teaching hospital, have higher surgical volume, be involved from the beginning of the case, and be interested in placenta accreta spectrum surgery. Those >10 years post-training and in the Southern US region are more likely to practice conservative management or delayed hysterectomy. CONCLUSION: This society-based cross-sectional survey suggests that gynecologic oncologists are actively involved in the surgical management of placenta accreta spectrum in the USA. Nearly half of gynecologic oncologists who responded to the survey expressed interest in surgery for placenta accreta spectrum.

Trends, characteristics, and outcomes of conservative management for placenta percreta.

PURPOSE: To examine trends, characteristics, and outcomes of women with placenta percreta who had conservative management at cesarean delivery (CD) without hysterectomy. METHODS: This is a retrospective cohort study querying the National Inpatient Sample. The Study population was comprised of women with diagnosis of placenta percreta who underwent CD from 10/2015-12/2018. Characteristics and surgical outcome of women who had hysterectomy at time of CD were compared to those who did not (conservative management) in multivariable analysis. RESULTS: A total of 1055 cases were examined, of which 790 (74.9%) received hysterectomy at CD and the remaining 265 (25.1%) had conservative management without hysterectomy. During the study period, performance of hysterectomy at CD increased from 71.4% to 93.8% (P < 0.001). In multivariable analysis, more recent cases of CD for placenta percreta were less likely to have conservative management [adjusted-odds ratio (aOR) per year-quarter 0.93, 95% confidence interval (CI) 0.89-0.97]. In contrast, hospitals with small-medium bed capacity (aOR 1.72, 95% CI 1.18-2.51), non-urban teaching setting (aOR 1.76, 95% CI 1.14-2.70), and located in the Midwest (aOR 2.55, 95% CI 1.56-4.17) were more likely to offer conservative management at CD. Later gestational age was also associated with a higher likelihood of conservative management (median gestational age, 36 versus 34 weeks, P < 0.001). Women in the conservative management group experienced lower measured surgical morbidity during the admission compared to those in the cesarean hysterectomy group (47.2% versus 75.9%, aOR 0.35, 95% CI 0.26-0.48). CONCLUSION: The clinical practice for placenta percreta appears to be shifting to upfront hysterectomy at the time of CD.

Paradigm shift from tubal ligation to opportunistic salpingectomy at cesarean delivery in the United States.

BACKGROUND: Opportunistic salpingectomy is now recommended at the time of routine gynecologic surgery to reduce the risk of future ovarian cancer, and performance of opportunistic salpingectomy has increased markedly at the time of benign hysterectomy. Salpingectomy has also been suggested to be feasible at the time of cesarean delivery in women desiring sterilization; however, uptake has not been previously studied on a national level. OBJECTIVE: This study aimed to examine recent population trends in the utilization and characteristics of salpingectomy at the time of cesarean delivery in the United States. STUDY DESIGN: This is a population-based retrospective observational study querying the National Inpatient Sample between October 2015 and December 2018. The primary outcome measure was the temporal trend of bilateral salpingectomy at cesarean delivery, assessed with linear segmented regression with log transformation utilizing 3-month time increments. The secondary outcome measures included patient characteristics associated with bilateral salpingectomy, assessed with a multinomial regression model, and surgical outcome (hemorrhage, blood transfusion, hysterectomy, and oophorectomy) at the time of bilateral salpingectomy vs bilateral tubal ligation, assessed with generalized estimating equation in a propensity score-matched model. RESULTS: There were 3,813,823 women at the age of 15 to 49 years who had cesarean deliveries included, of whom 397,260 (10.4%) had bilateral salpingectomy and 203,400 (5.3%) had bilateral tubal ligation overall. During the time period studied, performance of bilateral salpingectomy among women undergoing cesarean delivery significantly increased from 4.6% to 13.2% (odds ratio for the fourth quarter of 2018 vs the fourth quarter of 2015, 2.69; 95% confidence interval, 2.63-2.75; Figure panel). In contrast, performance of bilateral tubal ligation among women undergoing cesarean delivery significantly decreased from 11.3% to 2.4% (odds ratio, 0.20; 95% confidence interval, 0.19-0.21). By the third quarter of 2016, the number of women who had bilateral salpingectomy exceeded those who had bilateral tubal ligation at cesarean delivery (8.6% vs 7.3%). Increasing the utilization of bilateral salpingectomy did not vary across age groups; the salpingectomy rate increased from 7.5% to 21.1% among women at the age of ≥35 years and from 3.8% to 10.7% among women at the age of <35 years (both, P<.001). In a propensity score matched model, women in the bilateral salpingectomy group were more likely to have hemorrhage (3.8% vs 3.1%; odds ratio, 1.24; 95% confidence interval, 1.15-1.33), blood product transfusion (2.1% vs 1.8%; odds ratio, 1.16; 95% confidence interval, 1.04-1.30), hysterectomy (0.8% vs 0.4%; odds ratio, 2.28; 95% confidence interval, 1.84-2.82), and oophorectomy (0.3% vs 0.2%; odds ratio, 2.02; 95% confidence interval, 1.47-2.79) than those in the bilateral tubal ligation group. When restricted to the nonhysterectomy cases, the bilateral salpingectomy group had a higher rate of hemorrhage (3.4% vs 3.0%; odds ratio, 1.16; 95% confidence interval, 1.06-1.26) and oophorectomy (0.3% vs 0.1%; odds ratio, 1.75; 95% confidence interval, 1.22-2.50) than the bilateral tubal ligation group. CONCLUSION: In the United States, the utilization of bilateral salpingectomy at the time of cesarean delivery increased rapidly between 2015 and 2018, replacing tubal ligation as the most common type of sterilization performed with cesarean delivery. The higher surgical morbidity in the bilateral salpingectomy group than the bilateral tubal ligation group observed in this study warrants further investigation.

Trends, characteristics, and outcomes of placenta accreta spectrum: a national study in the United States.

BACKGROUND: Although an infrequent occurrence, the placenta can adhere abnormally to the gravid uterus leading to significantly high maternal morbidity and mortality during cesarean delivery. Contemporary national statistics related to a morbidly adherent placenta, referred to as placenta accreta spectrum, are needed. OBJECTIVE: This study aimed to examine national trends, characteristics, and perioperative outcomes of women who underwent cesarean delivery for placenta accreta spectrum in the United States. STUDY DESIGN: This is a population-based retrospective, observational study querying the National Inpatient Sample. The study cohort included women who underwent cesarean delivery from October 2015 to December 2017 and had a diagnosis of placenta accreta spectrum. The main outcome measures were patient characteristics and surgical outcomes related to placenta accreta spectrum assessed by the generalized estimating equation on multivariable analysis. The temporal trend of placenta accreta spectrum was also assessed by linear segmented regression with log transformation. RESULTS: Of 2,727,477 cases who underwent cesarean delivery during the study period, 8030 (0.29%) had the diagnosis of placenta accreta spectrum. Placenta accreta was the most common diagnosis (n=6205, 0.23%), followed by percreta (n=1060, 0.04%) and increta (n=765, 0.03%). The number of placenta accreta spectrum cases increased by 2.1% every quarter year from 0.27% to 0.32% (P=.004). On multivariable analysis, (1) patient demographics (older age, tobacco use, recent diagnosis, higher comorbidity, and use of assisted reproductive technology), (2) pregnancy characteristics (placenta previa, previous cesarean delivery, breech presentation, and grand multiparity), and (3) hospital factors (urban teaching center and large bed capacity hospital) represented the independent characteristics related to placenta accreta spectrum (all, P<.05). The median gestational age at cesarean delivery was 36 weeks for placenta accreta and 34 weeks for both placenta increta and percreta vs 39 weeks for non-placenta accreta spectrum cases (P<.001). On multivariable analysis, cesarean delivery complicated by placenta accreta spectrum was associated with increased risk of any surgical morbidities (78.3% vs 10.6%), Centers for Disease Control and Prevention-defined severe maternal morbidity (60.3% vs 3.1%), hemorrhage (54.1% vs 3.9%), coagulopathy (5.3% vs 0.3%), shock (5.0% vs 0.1%), urinary tract injury (8.3% vs 0.2%), and death (0.25% vs 0.01%) compared with cesarean delivery without placenta accreta spectrum. When further analyzed by subtype, cesarean delivery for placenta increta and percreta was associated with higher likelihood of hysterectomy (0.4% for non-placenta accreta spectrum, 45.8% for accreta, 82.4% for increta, 78.3% for percreta; P<.001) and urinary tract injury (0.2% for non-placenta accreta spectrum, 5.2% for accreta, 11.8% for increta, 24.5% for percreta; P<.001). Moreover, women in the placenta increta and percreta groups had markedly increased risks of surgical mortality compared with those without placenta accreta spectrum (increta, odds ratio, 19.9; and percreta, odds ratio, 32.1). CONCLUSION: Patient characteristics and outcomes differ across the placenta accreta spectrum subtypes, and women with placenta increta and percreta have considerably high surgical morbidity and mortality risks. Notably, 1 in 313 women undergoing cesarean delivery had a diagnosis of placenta accreta spectrum by the end of 2017, and the incidence seems to be higher than reported in previous studies.

Utilizations and outcomes of intra-arterial balloon occlusion at cesarean hysterectomy for placenta accreta spectrum.

INTRODUCTION: This study examined national-level trends, characteristics, and perioperative outcomes of women who had intra-arterial balloon occlusion at cesarean hysterectomy for placenta accreta spectrum (PAS). MATERIAL AND METHODS: This was a population-based retrospective observational study that queried the National Inpatient Sample from October 2015 to December 2018. Study population was women who underwent hysterectomy at cesarean delivery for PAS (n = 6440 in 806 centers). Exposure allocation was the use of intra-arterial balloon occlusion. Main outcome measures were (a) characteristics associated with intra-arterial balloon occlusion use, and (b) perioperative outcome including hemorrhage, blood transfusion, coagulopathy, shock, urinary tract injury, intra-arterial balloon occlusion-related complication (arterial injury, arterial thrombosis, and lower extremities ischemia), and death, assessed in multivariable analysis. RESULTS: Intra-arterial balloon occlusion was used in 420 (6.5%) women in 64 (7.9%) centers. Utilization of intra-arterial balloon occlusion during cesarean hysterectomy for placenta accreta decreased significantly over time (from 6.3% to 3.1%, p < 0.001), but not in placenta increta (from 12.8% to 9.3%, p = 0.204) or placenta percreta (from 21.3% to 17.5%, p = 0.344). In a multivariable analysis, patient factors (younger age, earlier year, obesity, diabetes mellitus), pregnancy factors (placenta increta/percreta, previous cesarean delivery, placenta previa, and early gestational age), and facility factors (large bed capacity, urban teaching status, and Northeast/West regions) represented the independent characteristics for using the intra-arterial balloon occlusion (all, p < 0.05). In a classification-tree model, the absolute difference in intra-arterial balloon occlusion use among 18 utilization patterns was 48% (range, 0%-48%). In perioperative outcome analysis, women who received intra-arterial balloon occlusion were more likely to have coagulopathy (adjusted odds ratio [aOR] 3.43) and arterial thrombosis (aOR 9.82) in placenta accreta, but less likely to have hemorrhage (aOR 0.25) in placenta increta, and blood transfusion (aOR 0.60) and urinary tract injury (aOR 0.28) in placenta percreta compared with those who did not (all, p < 0.05). CONCLUSIONS: There is a wide range in the utilization of intra-arterial balloon occlusion at cesarean hysterectomy for PAS based on patient, pregnancy, and facility factors, which implies that there is a lack of universal practice guidelines in this surgical procedure. Whether the use of intra-arterial balloon occlusion in the severe forms of PAS improves surgical outcome merits further investigation.

Uptake of postplacental intrauterine device placement at cesarean delivery.

BACKGROUND: Several studies have investigated the effectiveness of intrauterine device placement at cesarean delivery as a contraceptive method. However, national-level use and outcomes of a postplacental intrauterine device at cesarean delivery are currently understudied in the United States. OBJECTIVE: This study aimed to examine the trends, characteristics, and outcomes of patients who received a postplacental intrauterine device at cesarean delivery. STUDY DESIGN: This retrospective cohort study used the National Inpatient Sample. The study cohort included patients who underwent cesarean delivery from October 2015 to December 2018. The exclusion criteria included hemorrhage, chorioamnionitis, uterine anomaly, hysterectomy, and permanent surgical sterilization. Eligible cases were grouped on the basis of the use of a postplacental intrauterine device at cesarean delivery. The primary outcome measures were temporal trends and characteristics associated with the use of a postplacental intrauterine device at cesarean delivery, assessed using the generalized estimating equation model in multivariable analysis. The secondary outcome measure was perioperative morbidity (leukocytosis, endometritis, myometritis, and sepsis). Propensity score matching was used to balance the baseline characteristics. RESULTS: Among 2,983,978 patients who met the inclusion criteria, 10,145 patients (0.3%) received a postplacental intrauterine device at cesarean delivery. The use of a postplacental intrauterine device increased from 0.1% in the fourth quarter of 2015 to 0.6% in the fourth quarter of 2018 (P<.001). In a multivariable analysis, the use of a postplacental intrauterine device increased by 14% every quarter-year (adjusted odds ratio, 1.14; 95% confidence interval, 1.13-1.15). In addition, (1) patient characteristics of young age, non-White race, obesity, tobacco use, lowest quartile median household income, and insured with Medicaid; (2) hospital characteristics of large bed capacity and urban teaching setting in Northeast region; and (3) pregnancy characteristics of early gestational age at cesarean delivery, hypertensive disease, previous cesarean delivery, multifetal pregnancy, grand multiparity, placenta previa, and nonelective cesarean delivery represented the independent characteristics associated with the use of a postplacental intrauterine device (all P<.05). A regression tree model identified 35 discrete patterns of the use of a postplacental intrauterine device based on 8 factors (time, race or ethnicity, primary expected payer, obesity, hospital bed capacity, hospital teaching status, hospital region, and previous cesarean delivery). There were 9 patterns, representing 8.8% of the study population, exhibiting a use rate of ≥1.0%, whereas there were 7 patterns, representing 16.0% of the study population, exhibiting no use of a postplacental intrauterine device (absolute rate difference from the highest group to the lowest group, 4.7%). In a propensity score-matched model, postplacental intrauterine device placement at cesarean delivery was not associated with increased risk of measured morbidity (any, 1.8% vs 1.7%; odds ratio, 1.06; 95% confidence interval, 0.66-1.69; P=.812), including postpartum endometritis (1.2% vs 1.0%; odds ratio, 1.19; 95% confidence interval, 0.67-2.14; P=.554). CONCLUSION: The use of a postplacental intrauterine device at cesarean delivery increased significantly in recent years in the United States.

Pregnancy characteristics and outcomes after bariatric surgery: national-level analysis in the United States.

BACKGROUND: Bariatric surgery is an effective surgical treatment for weight reduction in individuals with obesity. Pregnancy outcomes related to prior bariatric surgery are currently under active investigation. OBJECTIVE: To assess national-level trends, characteristics, and outcomes of pregnancy after bariatric surgery in the United States. SETTING: Retrospective cohort study queried the National Inpatient Sample. METHODS: The study population was 14,648,135 patients who had vaginal or cesarean delivery from January 2016 to December 2019. Exposure allocation was based on the history of bariatric surgery. The main outcomes were (1) trends and characteristics related to bariatric surgery, assessed with multivariable binary logistic regression model; and (2) Centers for Disease Control and Prevention-defined severe maternal morbidity, assessed by propensity score matching and generalized estimating equation. RESULTS: A total of 53,950 (.4%) patients had prior bariatric surgery. The number of patients with prior bariatric surgery increased from .3% to .5%, and this trend remained independent in multivariable analysis (P < .001). Patients who had bariatric surgery were also more likely to be older and have obesity, medical co-morbidities, fetal growth restriction, preterm birth, and cesarean delivery compared with those without bariatric surgery (all, P < .05). In a propensity score matched model, patients who had bariatric surgery were more likely to receive blood product transfusion (2.3% versus 1.6%; odds ratio = 1.45; 95% confidence interval, 1.19-1.77), but severe maternal morbidity other than blood product transfusion was comparable to those without (1.1% versus 1.4%; odds ratio = .80; 95% confidence interval, .63-1.02). CONCLUSION: There is a gradual increase of pregnancy after bariatric surgery in recent years in the United States.

Prior vertical uterine incision: Effect on subsequent pregnancy characteristics and outcomes.

OBJECTIVE: To examine characteristics and outcomes of cesarean delivery (CD) in women with a history of vertical hysterotomy. METHOD: This is a comparative study that retrospectively queried the National Inpatient Sample from October 2016 to December 2018. Pregnancy characteristics and surgical outcomes of CD among 18 575 women with prior vertical uterine incision were compared to 1 072 949 women with prior low-transverse incision, assessed by multivariable generalized estimating equation model and propensity score weighting. RESULTS: In a multivariable analysis, women who had prior vertical uterine incision were more likely to have placenta percreta (odds ratio [OR] 3.41, 95% confidence interval [CI] 1.87-6.20), pre-labor uterine rupture (OR 2.70, 95% CI 1.52-4.80), in-labor uterine rupture (OR 2.33, 95% CI 1.55-3.51), and extreme preterm delivery <28 weeks (OR 17.8, 95% CI 15.2-20.7) in the current pregnancy, compared to those who had prior low-transverse uterine incision. In a weighted model, prior vertical hysterotomy was associated with increased surgical morbidity in current CD compared to prior low-transverse hysterotomy (10.6% vs. 4.8%, OR 2.02, 95% CI 1.81-2.26), including hemorrhage (OR 1.99, 95% CI 1.74-2.27) and hysterectomy (OR 3.67, 95% CI 2.97-4.53). CONCLUSION: Prior vertical uterine incision at CD was associated with increased risk of placenta percreta, uterine rupture, particularly before labor, and adverse outcomes in the subsequent pregnancy.

Racial and ethnic disparity in characteristics and outcomes of women with placenta accreta spectrum: a comparative study.

Placenta accreta spectrum (PAS) refers to the spectrum of diagnoses involving abnormally and morbidly adherent trophoblastic tissue to the gravid uterus. These disorders are associated with significant maternal morbidity and mortality. While race/ethnicity is known to impact pregnancy outcomes, racial disparities have not been previously examined in women with PAS. The objective of current study was to compare patient characteristics and perioperative outcomes of women with PAS who underwent cesarean delivery across race/ethnicity. This is a comparative study that retrospectively queried the National Inpatient Sample, a hospital-based inpatient database in the USA. The study cohort was women diagnosed with PAS who underwent cesarean delivery from 10/2015 to 12/2018. The exposure group was race/ethnicity. Main outcomes were (i) patient/pregnancy characteristics and (ii) surgical morbidity for cesarean delivery, assessed in multivariable analysis. A total of 10,535 women comprised the study cohort (White n = 5,230 [49.6%], Black n = 2,045 [19.4%], Hispanic n = 2,540 [24.1%], and Asian n = 720 [6.8%]). Patient demographics, pregnancy characteristics, and hospital factors for the non-White groups significantly differed compared to the White group. Older age, obesity, diabetes, placenta previa, percreta, non-elective surgery, lower median household income, and Medicaid particularly represented the non-White groups. When perioperative outcomes were compared, non-White women were more likely to have any measured complications, hemorrhage/transfusion, and shock/coagulopathy compared to White women. Various sensitivity analyses redemonstrated the main cohort results. In conclusion, this study suggests that there were significant disparities in patient characteristics and outcomes of women with PAS across race/ethnicity.

Fetal blood gases after in utero carbon dioxide insufflation for percutaneous fetoscopic spina bifida repair.

BACKGROUND: Prenatal repair of open spina bifida via the percutaneous fetoscopic approach does not require maternal laparotomy, hysterotomy, or exteriorization of the uterus. This technique requires intrauterine partial CO2 insufflation. Limited data exist on the physiological effects of CO2 insufflation on human fetuses, with no data on open spina bifida repair performed using the entirely percutaneous fetoscopic surgical technique. OBJECTIVE: Our aim was to examine the effects of intrauterine partial CO2 insufflation on fetal blood gases after percutaneous fetoscopic open spina bifida repair. STUDY DESIGN: This was a prospective study of patients who underwent percutaneous fetoscopic open spina bifida repair from February 2019 to July 2020. Fetal cordocentesis of the umbilical vein was performed in cases with favorable access to the umbilical cord. The umbilical vein cord blood samples were obtained under ultrasound guidance immediately at the conclusion of the open spina bifida repair. Simultaneous maternal arterial blood gas samples were also obtained. The results are reported as median (range). RESULTS: Of the 20 patients who underwent percutaneous fetoscopic open spina bifida repair during the study period, 7 patients (35%) underwent fetal blood sampling. The gestational age at the time of surgery was 27.4 (24.0-27.9) weeks and the operative time was 183 (156-251) minutes. The CO2 exposure time was 122 (57-146) minutes with maximum pressure of 13.5 (12.0-15.0) mm Hg. Fetal umbilical vein results were as follows: pH 7.35 (7.30-7.39), partial pressure of O2 56.2 (47.1-99.9) mm Hg, partial pressure of CO2 43.8 (36.2-53.0) mm Hg, HCO3 23.9 (20.1-25.6) mmol/L, and base excess -2.2 (-4.5 to -0.4) mmol/L. Simultaneous maternal arterial blood gas results were as follows: pH 7.37 (7.28-7.42), partial pressure of O2 187.5 (124.4-405.2) mm Hg, partial pressure of CO2 36.6 (30.7-46.0) mm Hg, HCO3 21.3 (18.0-22.8) mmol/L and base excess -3.2 (-5.9 to -1.8) mmol/L. CONCLUSION: Despite prolonged CO2insufflation of the uterus, fetal umbilical vein pH and base excess values did not approach those associated with potentially pathologic fetal acidemia.