Monoamniotic twins: a retrospective controlled study.

Monoamniotic twins are uncommon but are at high risk (reportedly 50%) for perinatal death, commonly from cord accidents. Until recently the diagnosis of monoamniotic twinning was seldom made before delivery, but modern ultrasound technology permits diagnosis during prenatal care, creating a management dilemma. This is a report of the experience with monoamniotic twins of 20 or more weeks' gestation at the University of Iowa Hospitals from 1961-1989. Twenty monoamniotic twin pregnancies were compared with 40 monochorionic, diamniotic controls regarding antepartum and intrapartum complications. Overall, monoamniotic twins were delivered earlier, were more likely to die in utero, and had lower birth weights than diamniotic twins. When only live-born twins were considered, however, there were no differences in gestational age at delivery, birth weight, or 5-minute Apgar scores. No fetal death occurred after 32 weeks, suggesting that prophylactic preterm delivery may not be indicated in all cases. Labor and vaginal delivery were not associated with an increased risk of fetal death.

Randomized, double-masked comparison of oxytocin dosage in induction and augmentation of labor.

OBJECTIVE: To test the hypothesis that high-dose oxytocin, when used in a masked fashion, would result in shorter labors and less need for cesarean delivery. METHODS: We conducted randomized, double-masked trials of high-dose compared with low-dose oxytocin for augmentation and induction of labor. Patients were randomly assigned to receive oxytocin by either a low-dose protocol (1.5 mU/minute initially, increased by 1.5 mU/minute every 30 minutes) or a high-dose protocol (4.5 mU/minute initially, increased by 4.5 mU/minute every 30 minutes). Oxytocin solutions were prepared by a central pharmacy and infusion volumes (mL/hour) were identical, thus ensuring double masking. RESULTS: A total of 1307 patients were randomized (induction, 816; augmentation, 491). In the group receiving oxytocin for induction, high-dose oxytocin was associated with a significant shortening of labor (oxytocin to complete dilatation: 9.7+/-0.3 compared with 7.8+/-0.2 hours, P<.001; oxytocin to delivery: 10.5+/-0.3 compared with 8.5+/-0.3 hours, P<.001). The cesarean delivery rate with low-dose oxytocin was 15.0%, compared with 11.3% with high-dose oxytocin (P = .17). For nulliparous women undergoing induction, cesarean delivery rates were as follows: Total 17.3% (low dose) compared with 11.7% (high dose), P = .15; cephalopelvic disproportion 11.9% (low dose) compared with 5.9% (high dose), P = .06. When used for augmentation, high-dose oxytocin again was associated with a significant shortening of labor without a significant difference in cesarean birth rates. No differences in neonatal outcomes were noted between the groups for either augmentation or induction. CONCLUSION: When used in a double-masked fashion, high-dose oxytocin is associated with significantly shorter labors without any demonstrable adverse fetal or neonatal effects.

Fundal height as a predictor of preterm twin delivery.

OBJECTIVE: To determine whether fundal height might predict early delivery in twin pregnancies; that is, whether larger fundal heights predispose to earlier delivery. METHODS: From the charts of 336 well-dated twin pregnancies, we generated a series of fundal height curves. RESULTS: Within our population of twin pregnancies, the mean fundal height at any given gestational age did not differ between pregnancies delivered before 34 weeks and those delivered at or after 34 weeks. A single fundal height measurement above the 90th percentile before 34 weeks yielded a sensitivity of 23% and a specificity of 79% for delivery before 34 weeks, with a positive predictive value of 38% and a negative predictive value of 64%. CONCLUSION: Factors other than uterine overdistention (as measured by fundal height) must be implicated in preterm twin delivery.

Human placental lactogen: a predictor of perinatal outcome?

Serial human placental lactogen (hPL) determinations were performed on 806 women with normal and abnormal pregnancies late in the pregnancy. These results were not reported to the clinicians involved. For the study population as a whole, low hPL levels did not effectively predict those adverse perinatal outcome variables evaluated. Further analysis revealed that this was true both for the normal and abnormal pregnancy groups. Our data do not support the routine use of antepartum hPL screening, as advocated by others, as a means of improving perinatal outcome. In certain at-risk patients, there was an association between low hPL values and the presence of 1 or more of the adverse outcome variables. However, these patients had been recognized clinically as having fetuses in jeopardy.

Preinduction cervical ripening with prostaglandin E2 intracervical gel.

A double-blind, placebo-controlled, dose-ranging study was undertaken to evaluate the efficacy of two doses of intracervical prostaglandin E2 gel in patients with unfavorable Bishop scores. Mean change in Bishop score, success of softening, time to labor, and time to delivery were all significantly different in the two treatment groups as compared with the placebo group. Twenty-three of 30 treated patients had uterine contractions lasting greater than four hours and eight patients delivered during the observation period. Moreover, one case of uterine hyperactivity and five cases of severe fetal heart rate decelerations were noted in the treatment groups. Although efficacious for cervical ripening, caution is warranted when using this technique in patients at risk for placental insufficiency.

Liver transplant after massive spontaneous hepatic rupture in pregnancy complicated by preeclampsia.

BACKGROUND: Spontaneous hepatic rupture associated with preeclampsia is a rare but life-threatening situation. Several different surgical treatments have been described, depending on the severity of the rupture. Liver transplantation has become the mainstay for patients with end-stage liver disease. Transplantation in the setting of liver trauma or massive parenchymal disruption is not well defined. To our knowledge, this treatment has not been reported for spontaneous hepatic rupture in pregnancy. CASE: Massive, spontaneous hepatic rupture occurred in a patient at 36 weeks' gestation as a result of severe preeclampsia. Conventional surgical therapies were unsuccessful in controlling the massive hemorrhage. As a life-saving measure, the patient underwent total hepatectomy with the creation of an end-to-side portcaval shunt, thereby rendering the patient anhepatic. The patient was listed as urgently needing a liver for transplantation through the United Network for Organ Sharing. A suitable donor liver was located approximately 8 hours after the emergency hepatectomy. The patient underwent orthotopic liver transplantation after being maintained in an anhepatic state for almost 13 hours. The patient was discharged on postoperative day 41, suffering only from some ischemic lower extremity neuropathy secondary to hypovolemic hypotension occurring during the hepatectomy procedure. CONCLUSION: In the reported case, spontaneous hepatic rupture resulted in a massive hemorrhage that could not be controlled by previously reported techniques and required total hepatectomy followed by liver transplantation.

Risk of repetition of a severe perineal laceration.

OBJECTIVE: To compare the outcome of subsequent delivery in women with a history of a third- or fourth-degree laceration with outcomes in women without such a history. METHODS: This retrospective study used a perinatal database and chart review from 1978 to 1995. Only women whose first delivery was at our institution at more than 36 weeks' gestation, vaginal singleton, vertex presentation, and birth weight greater than 2500 g, with a subsequent delivery were included. The women were grouped by presence or absence of a third- or fourth-degree (severe) perineal laceration in their first delivery. The subsequent delivery was analyzed for maternal age, weight, birth weight, gestational age, method of delivery, use of episiotomy, and occurrence of a severe laceration. Comparison of data was by Fisher exact and t tests. RESULTS: Four thousand fifteen women met our starting criteria. In their first delivery, the average birth weight, use of instrumentation, and episiotomy rate were significantly higher in those women sustaining a severe laceration. When compared with women without a history of severe perineal laceration, women with such a history were at more than twice the risk for another in their subsequent delivery. The women at highest risk (21.4%) were those sustaining a laceration in their first delivery who underwent instrumental vaginal delivery with episiotomy in their subsequent delivery. When episiotomy or instrumental delivery was performed in the second vaginal birth, 52 (11.6%) of 449 women with a history of a severe perineal laceration sustained another, compared with 98 (6.5%) of 1509 without such a history (P < .001, odds ratio 1.9, 95% confidence interval 1.3, 2.7). CONCLUSION: Women delivering their second baby, and in whom episiotomy or instrumentation is used, are at increased risk of severe perineal laceration compared with women delivery spontaneously.

hPL: physiologic and pathophysiologic observations.

Serum human placental lactogen (hPL) levels were studied in 806 women in late pregnancy. The hPL levels were positively correlated with birth weight but were unrelated to maternal age, parity, socioeconomic status, or the sex of the newborn. The hPL levels peaked at 37 weeks' gestation and then declined moderately. An individual's hPL levels in late pregnancy are quite constant week to week. Patients with severe chronic hypertension have low hPL values; those carrying twins have high values.

Histologic chorioamnionitis, microbial infection, and prematurity.

The purpose of this study was to relate histologic chorioamnionitis to the isolation of microorganisms from the freshly separated chorioamnion in women who had early preterm delivery (before 35 weeks' gestation) following spontaneous labor. Histologic chorioamnionitis was identified in 51 of 95 study subjects. It was more common in the second trimester (72%) than from 27-34 weeks' gestation (33%) (P less than .001). Culture specimens were obtained for aerobic and anaerobic bacteria, yeasts, mycoplasmas, and Chlamydia. Microorganisms were recovered from 38 subjects; all culture reports were negative in 36. A statistically significant association was demonstrated between histologic chorioamnionitis and positive culture results. If any microorganism was recovered, 68% of the subjects had histologic chorioamnionitis, versus 39% if all cultures were negative. Of cases of histologic chorioamnionitis in the third trimester, 92% were associated with positive cultures, compared with 54% in the second trimester. Our results suggest that histologic chorioamnionitis is not synonymous with infection, especially in the second trimester.

Reactions of residency directors to primary care requirements in obstetrics and gynecology training.

OBJECTIVE: To determine the opinions of obstetrics and gynecology residency program directors regarding the Residency Review Committee mandate, requires 6 months of primary care training in obstetrics and gynecology. METHODS: A ten-question survey was mailed to the 272 accredited obstetrics and gynecology programs in the United States and Puerto Rico. Program directors were asked about the adequacy of 6 months of primary care training, whether educational deficiencies in obstetrics and gynecology will develop as a result of the mandate, and whether residency programs should be lengthened to encompass primary care. RESULTS: The response rate for the survey was 92.3% (251/272). University-affiliated, community, and military-based programs were surveyed and all geographic areas of the country were represented. Of program directors responding, 53.4% agreed with the mandate, 43.0% disagreed, and 3.6% declined to answer this question or both agreed and disagreed. Fifty-one percent considered 6 months of primary care training to be adequate, and 60.2% of program directors thought that educational deficiencies would develop in obstetrics and gynecology training programs. Whereas 66.1% responded that extension of obstetrics and gynecology training programs beyond 4 years was unnecessary, 32.7% thought program length should be increased. CONCLUSION: The results of this survey demonstrate that a substantial proportion of U.S. residency directors do not agree with the Residency Review Committee mandate for primary care training and think that deficiencies in obstetrics and gynecology training will develop as a result of these changes.

Frequency, distribution, and theoretical mechanisms of hematologic and weight discordance in monochorionic twins.

OBJECTIVE: The purpose of this study was to determine the frequency, distribution, and most likely etiology of hematologic and weight discordance in pathologically proven monochorionic twins, and to use this information to reevaluate the neonatally derived definition of the twin-twin transfusion syndrome. METHODS: We reviewed our experience with 97 pathologically proven monochorionic twin pregnancies. The frequency and distribution of weight and hemoglobin-hematocrit (hb-hct) discordance were determined for all twin pairs. Factors that may have contributed to the discordance were identified, and theoretical mechanisms were proposed. RESULTS: All combinations of weight and hb-hct discordance were observed. Thirty-four twin pairs (35%) were discordant for weight. In half of these (17 of 34), the hb and hct were concordant. In 18% (six of 34), the smaller twin had the higher hb-hct, and in 32% (11 of 34), the smaller twin had the lower hb-hct. Twenty-three of 63 size-concordant pairs (36%) were discordant for hb-hct. Ten infants were infected at birth, eight had malformations, and 25 likely suffered an acute transfusion event. CONCLUSIONS: Any combination of weight and hb-hct discordance can occur in monochorionic twins. Acute and chronic twin-twin transfusion, uteroplacental insufficiency, infection, malformations, or other factors may have accounted for the discordance observed. Thorough antenatal evaluation with invasive testing and marker studies (to identify a physiologically unbalanced placental anastomosis) may be necessary to establish an accurate diagnosis. We conclude that weight and/or hb-hct discordance is relatively common in monochorionic twins and in itself is not sufficient to diagnose twin-twin transfusion.

Management of premature rupture of membranes at term.

Although prelabor rupture of membranes at term is common, in most cases, the spontaneous onset of labor relieves the obstetrician of the need for making management decisions. The standard practice in the United States has been to induce labor with intravenous oxytocin in that minority of patients who fail to labor spontaneously. Controlled trials suggest that this practice is associated with higher rates of both chorioamnionitis and the need for cesarean delivery than is expectancy. Expectancy, however, has not been demonstrated to be safer for the perinate.

Urinary urea nitrogen ratios: further observations.

The urea nitrogen/total nitrogen (UN/TN) and urea nitrogen/creatinine nitrogen (UN/CN) ratios in urine were compared as indicators of recent protein intake in pregnant women. The UN/CN ratio more accurately predicted recent dietary protein levels. The effects of other factors, including diabetes mellitus, on the UN/CN ratio were investigated. The UN/CN ratio is a simple and effective means of determining recent protein intake in the pregnant woman.

Dietary protein and human pregnancy performance.

Low birth weight is an important predictor of neonatal mortality and morbidity. Women of low socioeconomic classes give birth to disproportionate numbers of low-birth-weight infants and eat poorer diets than those of higher classes. Although maternal weight gain in pregnancy is positively associated with birth weight, and although animal studies demonstrate the important effects of protein restricti-n on reproductive performance, the significance or lack thereof of diet in general and of protein intake in particular in pregnant women in generally well-nourished populations has not been established. The conflicting data on human pregnancy performance and diet are critically reviewed.

Urinary nitrogen excretion as related to dietary protein in pregnant women.

The amount of urea in the urine acutely decreases when dietary protein is restricted. This change in urinary urea nitrogen can be represented satisfactorily by the urea nitrogen/total nitrogen (UN/TN) ratio or the UN/creatinine nitrogen (UN/CN) ratio. These determinations are apparently effective tools for simply and objectively describing the recent protein intake of pregnant women.

Interval evaluation of the cervix for predicting pregnancy outcome and diagnosing cervical incompetence.

The purpose of this study was to relate cervical compliance in the nonpregnant state to previous obstetric outcome in women with histories of early deliveries and to the length of gestation in subsequent pregnancies. One hundred eighty-four women with histories of spontaneous second-trimester abortions or early preterm deliveries had cervical evaluations in the interval state. Hysterography, catheter traction and dilator passage tests were utilized to generate a cervical compliance score, which was related to the weeks' gestation and clinical presentation in early delivery and to the length of gestation in subsequent pregnancies. Women with high scores (less cervical resistance) delivered their index pregnancies earlier in gestation than did women with low scores and were more likely to have presented with clinical cervical incompetence. In subsequent pregnancies, only 9% of pregnancies entering the second trimester in women with low scores delivered at < 30 weeks' gestation as compared with 24% in those with high scores. The evaluation of cervical compliance in the nonpregnant state is predictive of subsequent pregnancy outcome and therefore is a useful adjunct to the clinical history in diagnosing cervical incompetence.

Comparison of amniotic fluid optical density, L/S ratio and creatinine concentration in predicting fetal pulmonary maturity.

The optical density of amniotic fluid at 650 nm (OD650) has been proposed as a rapid means of assessing fetal pulmonary maturity. Two hundred eighty-two amniotic fluid samples were analyzed for OD650, L/S ratio and creatinine concentration, and those values were related to the infants' pulmonary outcome. Among those infants delivered within 72 hours of amniocentesis, pulmonary maturity was predicted accurately in 98.3% by the OD650, 97.7% by the L/S ratio and 97.6% by the creatinine concentration. All three tests were unreliable in predicting pulmonary complications when the tests revealed pulmonary immaturity. OD650 values were found to vary inversely with centrifugation speed, reaffirming the need for standardized processing techniques to achieve reliable results. Marked discrepancies occurred between the diagnoses given by three neonatologists asked to retrospectively evaluate the likely etiology of pulmonary problems in nine infants suspected of having respiratory distress syndrome.

Reported sexual behavior in late pregnancy. Selected associations.

The time intervals prior to delivery both for the last reported sexual intercourse and for the last reported orgasm were considered in terms of several variables in 413 puerperas. Although there were no significant differences in the reported time of last intercourse in terms of any of the demographic factors studied, orgasm in the absence of intercourse (reported events within seven days of delivery) was relatively more common and intercourse in the absence of orgasm relatively less common in study subjects with more years of formal education (p less than 0.01). Reported sexual behavior did not differ in respect to the length of gestation at delivery, selected pregnancy complications or the immediate condition of the newborn.

Chorionic mycoplasmas and prematurity.

In this study, recovery of Ureaplasma urealyticum and Mycoplasma hominis from the freshly exposed chorion following delivery was related to labor length but not to the interval between membrane rupture and delivery, to birth weight or to gestational age.

Radiologic appearance of the upper cervical canal in women with a history of premature delivery.

The aim of this study was to compare the radiologic appearance of the upper cervical canal at hysterography between a group of women with a history of premature delivery and a control group. A standardized technique was used that corrects for the magnification inherent in taking measurements directly from the x-ray films. Some women with a history of premature delivery had abnormally wide upper cervical canals in the nonpregnant state. Premature labor might not have been an acute pregnancy-specific event in those women but might have been a reflection of an underlying abnormality.