Correlation of umbilical cord blood haematopoietic stem and progenitor cell levels with birth weight: implications for a prenatal influence on cancer risk.

We examined the relation with birth weight and umbilical cord blood concentrations of haematopoietic stem and progenitor populations in 288 singleton infants. Across the whole range of birth weight, there was a positive relation between birth weight and CD34+CD38(-) cells, with each 500 g increase in birth weight being associated with a 15.5% higher (95% confidence interval: 1.6-31.3%) cell concentration. CD34+ and CD34+c-kit+ cells had J-shaped relations and CFU-GM cells had a U-shaped relation with birth weight. Among newborns with >or=3000 g birth weights, concentrations of these cells increased with birth weight, while those below 3000 g had higher stem cell concentrations than the reference category of 3000-3499 g. Adjustment for cord blood plasma insulin-like growth factor-1 levels weakened the stem and progenitor cell-birth weight associations. The positive associations between birth weight and stem cell measurements for term newborns with a normal-to-high birth weight support the stem cell burden hypothesis of cancer risk.

Accuracy of the TDx-FLM assay of amniotic fluid: a comparison of vaginal pool samples with amniocentesis.

OBJECTIVE: The purpose of this study was to evaluate the use of the TDx-FLM fluorescence polarization assay on vaginal pool fluid in patients with preterm premature rupture of membranes (PPROM). METHODS: A prospective matched-pairs study was performed at a tertiary care center. For each patient enrolled, amniotic fluid samples were obtained by sterile speculum examination and by amniocentesis within 12 h of each other. Inclusion criteria were the presence of PPROM and a gestational age of 30-36 weeks. The samples were analyzed separately using the TDx-FLM assay in the same laboratory. The results were compared using a paired Student t test. RESULTS: A total of 16 patients received both amniocentesis and vaginal collection of amniotic fluid. The mean gestational age at amniocentesis was 33.3 weeks (SD 1.9). In every case, the vaginal pool TDx-FLM result was lower than the amniocentesis result. The mean difference in the assays between the two fluid sources was 35% (range 17-63%, p < 0.001). Amniocentesis suggested a mature result in 12 cases (75%), an indeterminate result in two cases (12.5%), and an immature result in two cases (12.5%). Vaginal pool fluid suggested a mature result in four cases (25%), an indeterminate result in nine cases (56%), and an immature result in three cases (19%). Using the cut-off values validated for amniocentesis specimens as a standard for comparison, vaginal pool TDx-FLM assay had 42% sensitivity, 100% specificity, 100% positive predictive value and 36% negative predictive value for predicting lung maturity. CONCLUSIONS: The TDx-FLM assay on vaginal pool samples of amniotic fluid yielded results that were significantly different from those of amniocentesis samples. At this point, the assay is only clinically useful for vaginal pool samples when a mature result is obtained.

Closure of the subcutaneous dead space and wound disruption after Cesarean delivery.

OBJECTIVE: To determine whether suture closure of subcutaneous dead space decreases wound disruption after Cesarean delivery. METHODS: All patients undergoing Cesarean delivery at the New England Medical Center from September 1995 to June 1997 were eligible. One group (162 patients) was randomly assigned to have the subcutaneous fat layer closed with a running 3-0 plain suture. The other group (165 patients) had this layer left unclosed. Both groups had careful hemostasis of this layer with cautery and copious irrigation. All laboring and ruptured patients received prophylactic antibiotics. The patients were followed for 6 weeks after delivery for wound disruption. RESULTS: No significant differences were noted between the two groups with respect to demographic, obstetric, or surgical characteristics or loss to follow-up. Excluding those lost to follow-up (27 closed vs. 22 unclosed), there was no difference in wound infection (11 (8.1%) closed vs. 13 (9.1%) unclosed, RR 0.90, 95% CI 0.14, 2.08). There were decreases in risk of skin separation (three (2.2%) vs. six (4.2%), RR 0.53, 95% CI 0.42, 1.93) and seroma or hematoma formation (two (1.5%) vs. seven (4.9%), RR 0.30, 95% CI 0.06, 1.43) that were not statistically significant. Decreases that were not statistically significant were also noted for any wound disruption (14 (10.4%) vs. 21 (14.7%), RR 0.71, 95% CI 0.37, 1.33) and non-infected wound complication (three (2.2%) vs. eight (5.6%), RR 0.40, 95% CI 0.11, 1.47). Increasing gravidity and parity, and Cesarean delivery performed for failure to progress were independent risk factors for any wound complication. Controlling for these factors did not alter the effect of subcutaneous closure. CONCLUSIONS: Closure of the subcutaneous space does not increase and may protect against wound complications in patients undergoing Cesarean delivery.

Rupture of the renal pelvis associated with intravenous fluid bolus.

Previously reported cases of spontaneous rupture of the kidney or ureter reflect underlying renal pathology and have been reported both spontaneously and in relationship to delivery, but not in relation to other operative procedures. A 27-year-old woman at 19 weeks' gestation developed severe right flank pain in the operating room immediately prior to cerclage placement. Postoperative renal ultrasound examination and intravenous pyelogram performed to evaluate persistent flank pain demonstrated renal pelvis rupture. No other renal abnormality was present. We postulated that increased urine flow from the fluid bolus for the spinal anesthetic precipitated the rupture.

Pregnancy outcomes after prenatal diagnosis of aneuploidy.

OBJECTIVE: To determine the benefits of antenatal diagnoses of fetal aneuploidy in women who continued their pregnancies. METHODS: A questionnaire was mailed to 51 mothers of children with aneuploidy. Women whose fetuses were diagnosed prenatally comprised the study group and those whose infants were diagnosed at birth were controls. Outcomes measured included an assessment of pregnancy management, neonatal outcome, subjective measures of depression and anxiety, and evaluation of women's emotional and physical experience of the pregnancy. For outcomes measured by nonparametric survey questions, 20 women were needed in each arm to achieve a power of 80% to detect a 2-point difference on a 6-point scale; for our neonatal outcomes, 100 women were needed in each arm to achieve 80% power to detect a difference in length of stay (less than 1 week versus greater than 1 week) or need for surgery. RESULTS: Thirty-eight women (75%) responded. Most (86%) had children with trisomy 21. Seventeen women (45%) received their child's diagnosis at birth; 21 (55%) had prenatal diagnoses. Demographic measures were similar except that women with prenatal diagnoses attended religious services more frequently (1--3 times per month versus once to several times per year, P =.04). Women with prenatal diagnosis had better perceptions of their physical experience of pregnancy (median score of 10 versus 6 on a 10-point visual analog scale, P =.005) and their emotional experience of the birth (median score of 7.5 versus 2, P =.001). Mental Health Inventory scores were similar between groups. Neonates without prenatal diagnoses were more likely to be transferred to tertiary centers after birth (70% versus 24%, P =.004); lengths of hospital stays and need for surgery were similar. Seventy-one percent (95% confidence interval [CI] 48, 89%) of women with prenatal diagnoses said they would have done nothing differently in the pregnancy compared with 29% (95% CI 10, 56%) of women with diagnoses at birth. CONCLUSION: Early knowledge of fetal aneuploidy is beneficial to women who continue their pregnancies. These results might be useful when counseling women who do not intend to terminate abnormal pregnancies, but are considering prenatal diagnosis.

Prophylactic use of antibiotics for nonlaboring patients undergoing cesarean delivery with intact membranes: a meta-analysis.

OBJECTIVE: We performed a meta-analysis to examine the role of antibiotic prophylaxis in preventing postoperative infections among nonlaboring women undergoing cesarean delivery with intact membranes. STUDY DESIGN: A computerized literature search was performed with MEDLINE. Studies were included if they contained data on patients undergoing cesarean delivery in the absence of labor and ruptured membranes. Only randomized trials with a placebo control group were included. RESULTS: Seven studies were found. Use of antibiotics decreased the risk of all infectious outcomes reported. When the results of 4 studies were pooled, prophylactic antibiotic use was associated with a significant reduction in postoperative fever (relative risk, 0.25; 95% confidence interval, 0.14-0.44). A similar reduction was noted for endometritis in 4 studies (relative risk, 0.05; 95% confidence interval, 0.01-0.38). Two studies reported on wound infection and showed a trend toward a protective effect (relative risk, 0.59; 95% confidence interval, 0.24-1.45). CONCLUSION: The prophylactic use of antibiotics reduces the risk of postoperative infectious complications after cesarean delivery even in the population at lowest risk.

Impact of hormone replacement therapy on the body mass and fat compositions of menopausal women: a cross-sectional study.

OBJECTIVE: The purpose of the study was to compare the body mass and fat compositions of menopausal women who were taking conventional doses of hormone replacement therapy (HRT) with that of menopausal women who were not taking any hormones. DESIGN: The body fat composition of 169 healthy postmenopausal women was measured using a noninvasive handheld machine, the Electrolipograph (BioAnalogics ELG, Beaverton, OR, USA). Impedance to electrical flow in tissues is lower with increasing water content of the tissue. Information on HRT, lifestyle, diet, smoking, and alcohol was obtained from the medical record and by a telephone interview before women were invited to participate. HRT and non-HRT groups were compared. Multivariate linear regression, which included age, years since menopause, type of menopause, and use of HRT, was performed for each of the two major outcomes: body mass index (BMI) and percentage of body fat. RESULTS: Comparisons between subgroups showed a large number of significant differences reflecting differences in age since menopause, baseline BMIs, and baseline waist to hip ratios. In the regression model, however, the only factor significantly associated with lower fat and BMI was the use of HRT. Women who were taking HRT had significantly lower percentages of body fat (-4.8%; p < 0.001) and BMI (-2.6 kg/m2; p < 0.001) compared with nonusers. Age and duration and type of menopause were not significant predictors of weight and BMI in this group of postmenopausal women. CONCLUSIONS: In this study, HRT seems to be associated with a significant reduction in postmenopausal weight and fat mass gains. This may be an important mechanism by which HRT exerts its beneficial long-term effects on cardiovascular health.

Impact of gestational age at delivery of the economics of triplet pregnancy.

OBJECTIVE: To establish the charges associated with triplet pregnancies managed at a single tertiary center, over a 5-year time period, and to evaluate the impact of prematurity on these charges. METHODS: All triplet pregnancies that reached at least 20 weeks gestation and received prenatal and neonatal care at our center from 1992 to 1996 were included. Charges for these mothers and neonates were extracted from two separate hospital billing computer systems, encompassing all inpatient, outpatient, technical, and professional charges. Linear regression was used to evaluate the relationship between gestational age at delivery and total charges. RESULTS: Fifty-five triplet pregnancies were included, resulting in the admission of 149 liveborn neonates. The median gestational age at delivery was 32.1 weeks. The mean charges per triplet mother were: $6,899 (professional), $3,959 (hospital outpatient), and $32,686 (hospital inpatient). The mean charges per neonatal sibling set were: $20,107 (professional) and $124,163 (hospital inpatient). The mean charges per complete triplet pregnancy was $187,814 (maternal plus neonatal). There was a significant inverse relationship between gestational age at delivery and total charges per triplet family, with a decrease of $16,584 for each additional gestational week reached (P = 0.006). CONCLUSIONS: Triplet pregnancy charges averaged almost $190,000 each, which does not include charges associated with assisted reproductive technologies. These charges are almost all related to the expense of prolonged neonatal intensive care, and are significantly related to the gestational age at delivery. Efforts at containing these costs should focus on reducing the incidence of multiple gestation and preventing prematurity.

Myomectomy fever: testing the dogma.

OBJECTIVE: To test the hypothesis that elevated temperature is more common after abdominal myomectomy than after hysterectomy. DESIGN: Retrospective cohort study. SETTING: Academic medical center. PATIENT(S): One hundred one women who underwent abdominal myomectomy and 160 women who underwent total abdominal hysterectomy for benign disease from 1988-1993. INTERVENTION(S): Abdominal myomectomy. MAIN OUTCOME MEASURE(S): Temperature of > or = 38.5 degrees C within 48 hours after operation. RESULT(S): Although univariate analysis showed that the incidence of elevated temperature was slightly greater among patients who underwent myomectomy (33% versus 26%, relative risk 1.29, 95% confidence interval 0.88-1.90), multivariate logistic regression analysis showed a 3.29 relative risk of elevated temperature (95% confidence interval 1.56-6.96) with myomectomy after controlling for age, parity, estimated blood loss, and treatment by the general gynecology service. CONCLUSION(S): After controlling for confounders, myomectomy was found to be an independent predictor for fever in the first 48 hours after operation.

Neonatal morbidity and mortality associated with triplet pregnancy.

OBJECTIVE: To compare neonatal morbidity and mortality in a large cohort of triplet pregnancies with singleton and twin neonates managed at a single tertiary center over a short time. METHODS: Records from all triplet pregnancies managed and delivered from 1992 to 1996 were reviewed for neonatal outcome data. Pregnancies delivered before 20 weeks' gestation and neonates with lethal congenital anomalies were excluded. The comparison group comprised all singleton and twin neonates managed in the same neonatal intensive care unit (NICU) during the same period. RESULTS: During the 5-year period, 55 triplet pregnancies and their resulting 165 neonates were managed and delivered at this center. Their outcomes were compared with those of 959 singleton and 357 twin neonates born at similar gestational ages. The median gestational age at delivery for triplets was 32.1 weeks, and 149 of the 165 infants were admitted. Sixteen triplet neonates were not admitted to our neonatal intensive care unit, 12 because of previable gestational age, three because of stillbirth, and one because of a lethal congenital anomaly. The crude perinatal mortality rate in triplets was 121 per 1000 births, and there was no significant difference in outcome based on triplet birth order. There were no significant differences in survival rates between singleton, twin, and triplet neonates, with an overall neonatal survival of 95%, 95%, and 97%, respectively. The only significant differences in morbidity were an increased incidence of mild intraventricular hemorrhage (relative risk [RR] 6.20; 95% confidence interval [CI] 2.64, 14.61), mild retinopathy of prematurity (RR 20.05; 95% CI 3.59, 111.79), and severe retinopathy of prematurity (RR 46.69; 95% CI 6.25, 348.85) in triplets compared with singletons, and severe retinopathy of prematurity (RR 6.83; 95% CI 1.24, 37.56) in triplets compared with twins. CONCLUSION: When stratified by gestational age, triplet neonates delivered at 24-34 weeks' gestation have similar outcomes as singleton and twin neonates, with the only clinically significant difference being an increased incidence of retinopathy of prematurity in triplets.

Maternal morbidity associated with triplet pregnancy.

The objective of this article is to describe maternal morbidity in a large cohort of triplet pregnancies managed by a single Maternal-Fetal Medicine group over a short period of time. Records from all triplet pregnancies managed and delivered from 1992 to 1996 were reviewed for maternal outcome data. Pregnancies delivered prior to 20 weeks were excluded. During the 4-year study period, 55 triplet pregnancies were managed and delivered at this center. The most common maternal complication was preterm labor, which occurred in 42 cases (76%). Preterm premature rupture of membranes occurred in 11 cases (20%). Pregnancy-induced hypertensive complications occurred in 15 cases (27%), which included severe preeclampsia 13 (24%), hemolysis, elevated liver function tests, and low platelets (HELLP) syndrome 5 (9%), and eclampsia 1 (2%). Other maternal antenatal complications included anemia 15 (27%), acute fatty liver of pregnancy 4 (7%), gestational diabetes 4 (7%), supraventricular tachyarrhythmias 2 (4%), dermatoses 2 (4%), urinary tract infection 2 (4%), and acute disc prolapse requiring surgery in 1 case (2%). Postnatal complications occurred in 18 cases (33%), including endometritis 13 (24%), postpartum hemorrhage 5 (9%), pneumonia 2 (4%), urinary tract infection 2 (4%), and diastasis of rectus muscles requiring surgery in 1 (2%). There were no maternal deaths. Antenatal and postnatal maternal complications occur in almost all triplet gestations, suggesting that such pregnancies be managed at centers that have appropriate multidisciplinary expertise available.

Oligohydramnios and the appropriately grown fetus.

The perinatal implications of oligohydramnios prior to 37 weeks of gestation, in the absence of intrauterine growth restriction (IUGR), rupture of membranes or fetal anomalies, are unknown. We compared the outcomes of 65 women with oligohydramnios (amniotic fluid index ([AFI] < or = 8 cm) by sonography to those of a control group matched by sonogram indication. Study patients were between 17 and 37 weeks of gestation, with appropriately grown fetuses on index sonogram and no other detected explanation for amniotic fluid abnormalities. Patients were managed expectantly with fetal testing and follow-up sonograms for fetal growth. Delivery was not recommended solely for oligohydramnios until 37 weeks of gestation. Patients with isolated oligohydramnios prior to 37 weeks of gestation, when compared to a control group with normal amniotic fluid volume, had a significantly higher incidence of premature delivery (odds ratio [OR] 3.23, 95% confidence interval [CI] 1.4-7.3) but did not appear to be at increased risk of IUGR, intrauterine death, or birth asphyxia.

Defining the role of fluorescence in situ hybridization on uncultured amniocytes for prenatal diagnosis of aneuploidies.

OBJECTIVE: This study examines the role of fluorescence in situ hybridization on uncultured amniocytes for prenatal diagnosis in a population at high risk for aneuploidies. STUDY DESIGN: All patients undergoing amniocentesis for fetal structural abnormality on ultrasonographic examination (performed from 13 to 39 weeks), abnormal maternal serum aneuploidy screening results, or advanced maternal age with substantial parental anxiety were offered both fluorescence in situ hybridization on uncultured cells and conventional metaphase karyotyping on dividing cells. RESULTS: From 1992 to 1995, 315 patients were studied. Mean time to obtain results was 2.8 days for fluorescence in situ hybridization and 8.3 days for karyotype. Fluorescence in situ hybridization was informative in 254 samples (80.6%), and within this group 21 aneuploidies were correctly identified. Among informative specimens there was 100% sensitivity and specificity, with 100% positive and negative predictive values. Of the 315 samples, 61 (19.4%) were uninformative or unreportable. Of 25 total cases of karyotype-proved aneuploidy, 4 were reported as uninformative by fluorescence in situ hybridization, for a total detection rate of 84%. Overall, amniocenteses performed after 24 weeks were significantly more likely to be uninformative than those performed in the second trimester (45% vs 16%, p = 0.01), peaking at a 56% uninformative rate after 33 weeks. Logistic regression analysis showed an 8% increase in the uninformative rate per week of gestational age (odds ratio 1.08, 95% confidence interval 1.04 to 1.14). CONCLUSIONS: Fluorescence in situ hybridization on uncultured amniocytes is a rapid, clinically useful tool for prenatal diagnosis, with informative specimens being highly accurate. The combination of a structural fetal anomaly and an abnormal fluorescence in situ hybridization result should allow for definitive management decisions. The significant increase in uninformative specimens at later gestational ages limits its usefulness in the third trimester.

Pregnancy complicated by obsessive-compulsive disorder.

Obsessive-compulsive disorder (OCD) is a well-recognized psychiatric disorder often beginning in reproductive age. A case of OCD in pregnancy is presented and its management discussed. A 28-year-old G3P2 woman presented at 8 weeks' gestation for prenatal care. She had been diagnosed with OCD following her prior pregnancy. Her symptoms primarily involved obsessions about infectious disease and compulsive cleaning and organization of household items, both of which greatly distressed her and interfered with caring for her children. She had been managed with clomipramine between pregnancies and was beginning a clinical trial of fluvoxamine when pregnancy was diagnosed. She discontinued medication when she realized she was pregnant. Her symptoms were managed during the pregnancy with frequent appointments with her obstetrician and her psychiatrist. She used a behavioral technique, "thought-stopping", as well. Her symptoms worsened in the last month of pregnancy and immediately after delivery; she delivered a normal infant. The clomipramine was restarted postpartum. She has done well since then, with minimal psychiatric symptoms. OCD is a disabling psychiatric disorder that occurs in women of reproductive age. With careful management, pregnancy without disabling psychiatric symptoms can occur.

Relative morbidity of abdominal hysterectomy and myomectomy for management of uterine leiomyomas.

OBJECTIVE: To compare the morbidity of total abdominal hysterectomy and abdominal myomectomy in the surgical management of uterine leiomyomas. METHODS: Hospital records were reviewed for all women who underwent hysterectomy (n = 89) or myomectomy (n = 103) between May 1, 1988, and May 1, 1993, for the preoperative diagnosis of leiomyoma. RESULTS: There were significant differences between the two groups for average age (hysterectomy 39.2 years, myomectomy 34.4 years; mean difference 4.8, 95% confidence interval [CI] of difference 3.7-5.9), uterine size (hysterectomy 15.2, myomectomy 11.5 weeks; mean difference 3.8, 95% CI of difference 2.0-5.4) and use of a GnRH agonist (hysterectomy 23.6%, myomectomy 55.3%; relative risk [RR] 0.4, 95% CI 0.3-0.6). Myomectomy was associated with decreased estimated blood loss (hysterectomy 796 mL, myomectomy 464 mL; mean difference 331, 95% CI 121-542) and febrile morbidity (risk of temperature 38C or 48 or more hours postoperatively: for hysterectomy 49.4%, for myomectomy 32%; RR 1.5, 95% CI 1.1-2.2). Using multivariate linear regression, estimated blood loss was similar between the groups after controlling for uterine size. There was no difference in blood transfusion rates. There were two ureteral, one bladder, one bowel, and one femoral nerve injury in the hysterectomy group, and there were no intraoperative visceral injuries in the myomectomy group. CONCLUSION: Myomectomy compares favorably to hysterectomy in the surgical management of leiomyomas, with a possible decreased risk for visceral injury and infection.

Prolonged labor in nulliparas: lessons from the active management of labor.

OBJECTIVE: To define factors causing prolonged labor in nulliparous women undergoing active management of labor. METHODS: We included all nulliparas delivered during 1990-1994 with spontaneous onset of labor lasting more than 12 hours, singleton gestation, cephalic presentation, and labor at greater than 37 weeks. Each patient was matched with the next nulliparous woman who delivered with a labor lasting less than 12 hours and who fulfilled the same inclusion criteria. Subjects were managed according to the previously described active management of labor protocol from The National Maternity Hospital, Dublin. RESULTS: In the 5-year period, 9018 nulliparas met inclusion criteria, with 147 (1.6%) having prolonged labor. Prolonged labor was due to inefficient uterine action in 65%, persistent occipitoposterior position in 24%, and cephalopelvic disproportion in 11% of cases. Univariate analysis showed statistically significant (P < .05) differences in maternal body mass index, cervical dilation on admission, oxytocin use, epidural use, placement of epidural at less than 2 cm of dilation, and birth weight between these study groups. On multivariate conditional logistic regression analysis, the following were significant independent predictors for having a prolonged labor (odds ratios with 95% confidence intervals presented): 3.1 (1.3-7.3) for cervical dilation less than 2 cm on admission, 42.7 (7.5-242.0) for early epidural placement, 5.1 (1.9-13.7) for epidural placement at greater than or equal to 2 cm, and 10.2 (3.6-29.4) for birth weight greater than 4000 g. CONCLUSION: Less-advanced cervical dilation on admission and epidural use, especially when placed early, are strongly associated with prolonged labor.

Outcome of twin gestations complicated by a single anomalous fetus.

OBJECTIVE: To compare the outcome of twin gestations complicated by a single anomalous fetus with twin gestations with no fetal anomalies. METHODS: The study included all patients with twin gestations diagnosed with a fetal anomaly in one fetus during 1990-1994, and excluded twin gestations with anomalies in both fetuses. The control twin group was composed of all other normal twin pregnancies followed and delivered at our center in the preceding 2 years. RESULTS: We reviewed 24 twin gestations with at least one anomalous fetus. Five cases were excluded because of anomalies in both fetuses, and a further five pregnancies had selective termination or termination of the entire pregnancy. There were 14 ongoing twin pregnancies with one anomalous fetus, and their median gestational age at diagnosis was 18 weeks (range 16-20). All twin anomalies were correctly diagnosed antenatally. Gestational age at delivery and birth weight were significantly lower for twins complicated by an anomaly compared with control twins (P = .008 and P = .001, respectively). The cesarean delivery and perinatal mortality rates of twin pregnancies with anomalies were significantly higher than those of normal twins (P = .01 and P < .001, respectively). CONCLUSION: The presence of a single anomalous fetus in a twin gestation significantly increases the risk of preterm delivery compared with nonanomalous twin gestations.

Maternal cigarette smoking and placenta previa.

OBJECTIVE: To identify the relationship between maternal cigarette smoking and ultrasound-confirmed placenta previa. METHODS: A matched case-control design was used. Cases were drawn from the New England Medical Center and Cambridge Hospital from July 1992 through March 1994. Each case was delivered by cesarean after 24 weeks' gestation and had an antenatal ultrasound examination confirming placenta previa. Matched controls were obtained by requesting records on the first three deliveries by the referring provider the same month as the index case. Data on potential risk factors were drawn from the records of the initial prenatal visit, before previa was diagnosed. The data were analyzed with conditional logistic regression. RESULTS: Thirty-two cases of ultrasound-documented placenta previa were identified. A number of potential confounders were associated with previa: age (odds ratio [OR] 1.15, 95% confidence interval [CI] 1.05-1.26), gravidity (OR 1.4, 95% CI 1.1-1.7), parity (OR 1.4, 95% CI 1.1-1.9), prior spontaneous abortion (OR 3.1, 95% CI 1.3-7.4), prior elective abortion (OR 3.0, 95% CI 1.2-7.6), and prior cesarean delivery (OR 3.5, 95% CI 1.3-9.9). The crude OR for current smoking was 3.0 (95% CI 1.1-8.6). The OR for smoking ranged from 2.6-4.4, despite controlling for confounders. CONCLUSION: Current cigarette smoking is associated with a 2.6-4.4-fold increased risk of placenta previa.

Maternal intravenous hydration and amniotic fluid index in patients with preterm ruptured membranes.

OBJECTIVE: To examine the effect of an intravenous (i.v.) fluid bolus on the amniotic fluid index (AFI) in patients with preterm ruptured membranes. METHODS: Nonlaboring patients at 24-37 weeks' gestation with documented ruptured membranes were randomized to either no hydration or to an i.v. fluid bolus with 1 L of normal saline administered over 30 minutes. All patients had a baseline AFI measured. The same blinded examiner repeated the examination 90 minutes later. RESULTS: Six patients were randomized to the hydration group, seven to the control group. The groups were similar in age, gravidity, parity, time since rupture, gestational age, and baseline AFI. In the hydration group, the AFI increased 5.1 cm (95% confidence interval [CI] 2.9-7.3) after the fluid bolus. In the no-hydration group, the change was 0.6 cm (95% CI-1.1 to 2.2). The difference in the change in AFI between groups was 4.5 cm (95% CI 1.3-7.7) (P = .008). CONCLUSION: The AFI is sensitive to maternal hydration in patients with preterm rupture of membranes and can be increased with an i.v. fluid bolus.