Variation of force applied during external cephalic version with different patients' characteristic and outcome of version.

BACKGROUND: To compare the degree of force applied during external cephalic version, between different patients' characteristic and outcomes of version. METHODS: It is a prospective observational study in a cohort of patients undergoing external cephalic version at or above 36 weeks of gestation. During external cephalic version, the operator wore a pair of pressure-sensing gloves which had ultra-thin piezo-resistive pressure sensors positioned on the palmer surface. Readings from each of the sensors were recorded in real time throughout each version attempt and analyzed by a computer program. The pressure exerted on individual sensors over time, the pressure-time integral (PTI; mmHg s), was calculated for each sensor from the start to the end of each version attempted. The degree of force applied for each attempt (PTI-A) was represented by the sum of pressure-time integrals across all sensors. PTI-A was analyzed in relation to different patients' characteristics and outcome of version. RESULTS: Ninety-two patients were recruited, 73% of whom had a successful external cephalic version. The median PTI-A of the successful attempt in women who completed version after 1 and 2 attempts were 17,180 and 17,736 mmHg s, respectively. They were significantly lower than that of the women who required 3 or more attempts for a successful version (32,351 mmHg s), as well as the highest PTI-A among all attempts received by women who finally had a failed version (31,638 mmHg s) (p <0.05, Kruskal-Wallis Test and Dunn test). Within the same subject, there was no difference in PTI-A between the successful attempt and the preceding failed attempt, suggesting that the failure may not be due to insufficient force but rather to inefficient application of the force. Uterine tone was found to be the only clinical variable that was significantly associated with the degree of applied force during a version (p < 0.05). A tenser uterus was associated with a stronger applied force. CONCLUSION: The degree of force required for a successful version is highly variable, being lowest when version can be completed within 2 attempts, but doubled when 3 or more attempts are required. Failure of version is usually not due to inadequate force but inefficient application of force. Uterine tone is significantly related to the degree of applied force, with stronger force being exerted when the uterus is tense.

Cord blood thyroid-stimulating hormone level and risk of acidosis at birth.

OBJECTIVE: Cord blood thyroid-stimulating hormone level is elevated in neonates who had undergone more perinatal stresses. The present study aimed to evaluate the cord blood acid-base status in neonates with elevated thyroid-stimulating hormone level. STUDY DESIGN: The study population consisted of 2366 singleton, term pregnancies. Subjects were categorized by their cord blood thyroid-stimulating hormone level into four quartiles, and cord blood acid-base parameters were compared among the four groups. The correlations between cord acid-base parameters and thyroid-stimulating hormone level were also studied. RESULTS: Cord blood pH was significantly lower in the highest (arterial, 7.27+/-0.08; venous, 7.32+/-0.07) and second highest thyroid-stimulating hormone quartile groups (arterial, 7.29+/-0.07; venous, 7.34+/-0.06) compared to the lowest quartile group (arterial, 7.30+/-0.06; venous, 7.35+/-0.05). Incidences of cord arterial pH < or =7.20 were 4.7%, 6.8%, 10.9%, and 17.3% in lowest to the highest thyroid-stimulating hormone quartile groups, respectively. There was a significant negative correlation between cord blood thyroid-stimulating hormone level and cord arterial and venous pH (r=-0.26, P<0.001). When stratified according to the mode of delivery, the negative correlations remained significant in neonates delivered vaginally and by intrapartum emergency cesarean section but not in neonates delivered by elective cesarean section. CONCLUSION: Incidence of cord blood acidosis is significantly higher in neonates with elevated thyroid-stimulating hormone level. This findings support the postulation that stress-induced elevation of cord blood thyroid-stimulating hormone level may be mediated through intrapartum fetal hypoxia.

When to induce labor for post-term? A study of induction at 41 weeks versus 42 weeks.

OBJECTIVE: To evaluate the pregnancy outcomes of two policies of timing of induction of labor for post-term pregnancies. STUDY DESIGN: It is a retrospective study in a University obstetric unit from 1997 to 2002. Five thousand eight hundred and ninety-two singleton, cephalic pregnancies with gestational age at delivery at or more than 41 completed weeks were studied. They were divided into two groups. Group A included women who delivered from January 1997 to February 1999 when the policy of the department was to induce labor for post-maturity at 42 weeks of gestation. Group B included those delivered between March 1999 and December 2002 when the timing of induction for post-term was advanced to 41 weeks. The intrapartum characteristics, delivery and perinatal outcomes were analyzed by Student's t-test and Chi-square test for continuous and categorical variables, respectively. RESULTS: Two thousand one hundred and seventy-six women were studied in Group A and 3716 in Group B. Twenty-nine percent of these pregnancies in Group A required induction of labor whereas 20.3% were for post-term. In Group B, 58% of pregnancies had labor induction and 55% for post-maturity. For the pregnancies undergoing induction of labor for post-term, both the duration of labor (P<0.001) and the need of intrapartum epidural analgesia were increased (OR 1.3, 95% CI: 1.0-1.6) in Group B. However, there was no significant difference in the mode of delivery, apgar scores and stillbirths between the two study periods. CONCLUSION: Compared to routine induction at 42 weeks, induction at 41 weeks is associated with a significantly higher risk of use of medical interventions and associated complications, with no observable benefits.

Sexual dysfunction after a first trimester induced abortion in a Chinese population.

OBJECTIVE: To evaluate the short-term effect of a first trimester induced abortion on sexuality in a Chinese population. STUDY DESIGN: This is a cross-sectional study. One hundred and four women attending the post-abortion clinic 3-4 months after a first trimester induced abortion were recruited. They completed a self-administered questionnaire anonymously. The associations of various factors with sexual behavior after abortion were analyzed by the Chi-square test. RESULTS: More than 30% of the women reported a reduction in both frequency of vaginal intercourse and sexual desire. Their partners also had a reduction in sexual desire. The reduction of vaginal intercourse is more significant among young, unmarried women and those not having sterilization (P=0.01). In addition, the prevalence of reduction in sexual desire and enjoyment among those women who had repeated abortion was significantly higher (P<0.01). CONCLUSION: The sexuality of both women and their partners are affected after abortion. It may be due to both psychological trauma and the worry of another unwanted pregnancy. Proper counseling may relieve their anxiety and improve sexual lives.

Effect of prostaglandin E2 for cervical priming on fetal hemodynamics.

OBJECTIVE: To assess the effect of the prostaglandin E2 (PGE2) on fetal vascular blood flow during cervical priming. STUDY DESIGN: In a prospective, observational study, 32 pregnant women > or =37 weeks of gestation requiring PGE2 for induction of labor were recruited. The resistance indices (RIs) of umbilical artery, middle cerebral artery, renal artery and ductus venosum were measured before, 2 and 4 hours after insertion of a PGE2 vaginal pessary. RESULTS: There were no significant changes in RIs of various fetal vessels during cervical priming with PGE2. CONCLUSION: There was no significant change in fetal hemodynamics after vaginal prostaglandin administration. This finding provides further evidence to support the safety of prostaglandin for normal fetuses.

Reference charts of gestation-specific tissue Doppler imaging indices of systolic and diastolic functions in the normal fetal heart.

BACKGROUND: Assessment of fetal cardiac function is difficult because of limited accessibility. Tissue Doppler imaging (TDI) is a promising technique in assessing diastolic function in adults. There has been sparseness concerning the use of TDI in assessing fetal cardiac function. The aim of this study was to construct reference charts of TDI indices of systolic and diastolic functions of the normal fetal heart. METHODS: Ventricular myocardial velocities at the left ventricular (LV) wall, right ventricular (RV) wall, and interventricular septum (IVS) were assessed by TDI in 302 subjects. RESULTS: From 19 to 37 weeks of gestation, peak myocardial velocities during early diastole (Em) increased from 3.3 to 7.2, 3.9 to 8.3, and 3.2 to 5.0 m/s at the LV wall, RV wall, and IVS, respectively. Peak myocardial velocities during atrial contraction (Am) also increased throughout gestation, but the magnitude of increase was smaller (6.3 to 7.9, 7.7 to 10.6, and 5.5 to 5.9 m/s for the LV wall, RV wall, and IVS, respectively). As a consequence, the Em/Am ratio increased from 0.51 to 0.61 at midtrimester to 0.76 to 0.91 at term. Similar to Em, peak myocardial velocities during systole (Sm) also increased by almost 2 times from 18 to 37 weeks of gestation (3.8 to 6.0, 4.2 to 7.6, and 3.3 to 5.6 for the LV wall, RV wall, and IVS, respectively). Reference charts of gestation-specific Em, Am, Em/Am ratio, Sm, and E/Em were constructed accordingly. CONCLUSIONS: In midtrimester, fetal diastolic function is predominantly contributed by atrial contraction. As gestation advances, ventricular relaxation becomes increasingly mature. Reference charts for TDI indices were constructed, these will allow identification of fetuses with an abnormal diastolic function.

Sexual behavior and activity in Chinese pregnant women.

OBJECTIVE: To evaluate sexual activities, attitudes, and complications related to intercourse among Chinese pregnant women and to study their source of the information. METHODS: This was a prospective cross-sectional study. Two hundred and ninety-eight Chinese pregnant women were recruited. Pregnant women completed a self-administered questionnaire anonymously. Their sexual experience and sexuality were analyzed and compared among trimesters. Multiple logistic regression was used to assess the association of various factors with a number of outcomes concerning the sexuality in pregnancy. RESULTS: Ninety-three percent of the pregnant women reported an overall reduction in their sexual activities during pregnancy. Among these activities, vaginal intercourse significantly decreased in the third trimester. Besides gestation, advanced maternal age and nulliparity were independent factors associated with the reduction of vaginal intercourse (P < 0.001). Moreover, over 60% of the women, as well as more than 40% of their partners, had reduction in sexual desire and enjoyment during pregnancy. Over 80% of the women and their partners worried about the adverse effects of sexual activity on the fetus. However, less than 12% of them experienced complications after coitus during pregnancy. Among them, only 9.4% discussed sexuality with their doctors and half of them raised up this topic by themselves. CONCLUSION: Chinese pregnant women had less sexual activities and desire during pregnancy. Culture, inadequate knowledge, and excessive anxiety are likely the important factors for the marked reduction in sexuality in Chinese couples. Medical staffs should take a proactive role in providing more information to relieve their anxiety.

Maternal experience of pain during external cephalic version at term.

BACKGROUND: This study was designed to investigate maternal pain perception during external cephalic version (ECV). METHODS: This prospective study included 97 pregnant women with singleton breech presentation at or above 36 weeks of gestation undergoing ECV. No analgesia or anesthesia were used during ECV. The women were asked to rate the degree of pain on a 10-cm visual analog scale after ECV. RESULTS: Ninety-eight ECVs were performed and the overall success rate was 66%. The median pain score was 5.7 (interquartile range 2.7-6.8). The visual analog pain score was significantly lower among those with a successful ECV than those with a failed procedure (median score 4.6 vs. 6.8, p < 0.001). Similarly, those procedures rated as easy by the operator were associated with a significantly lower pain score (3.4 vs. 6.4, p < 0.001). However, the pain score was not found to be related to the operator, parity or placental site. Among the five subjects with a pain score of 8.5 and beyond, the ECV procedure was still successful in four (80%). CONCLUSION: ECV performed without analgesia was associated with a moderate degree of pain that was well tolerated by the majority of patients because of its short duration.

Fetal hemodynamic changes after amniotomy.

BACKGROUND: The aim of the study was to assess fetal vascular blood flow after amniotomy. METHODS: This was a prospective observational study. Thirty-five women with singleton pregnancy beyond 36 weeks of gestation, who underwent amniotomy, were recruited. The pulsatility indices of the fetal middle cerebral artery (MCA), the renal artery, and the ductus venosum were measured before and 30 min following amniotomy. The changes in pulsatility index were compared by means of Wilcoxon signed rank test. RESULTS: There was a significant reduction in pulsatility indices of the MCA (median reduction: 0.23; interquantile range (IQR): -0.04, 0.4) and the renal artery (median reduction: 0.12; IQR: -0.12, 0.54) after amniotomy. However, there was no obvious change in the ductus venosum (median reduction: 0.00; IQR: -0.06, 0.1). CONCLUSIONS: Amniotomy is associated with significant reduction in the impedance of the fetal MCA and the renal artery. The former may be a result of fetal stress response and the latter could be related to the release of vasoactive substances after amniotomy.

Prediction of successful vaginal delivery in women undergoing external cephalic version at term for breech presentation.

OBJECTIVE: The aim of this study is to evaluate the clinical and sonographic predictors of ultimate successful vaginal delivery in women undergoing external cephalic version. STUDY DESIGN: The study population consisted of women with external cephalic version performed at or after 36 weeks of gestation. They were randomized into group A or B, each consisted of half of the total study population. Logistic regression was performed on group A to identify the significant independent variables in predicting successful cephalic vaginal delivery, which were used to construct a prediction model. The derived regression model was then tested in group B to assess its accuracy. RESULTS: The study included 407 pregnancies. Maternal weight (kg) at the time of version, maternal height (cm), multiparity, engagement of fetal presenting part, and fetal head palpable were significant independent variables of successful version and vaginal delivery (regression coefficients are: -0.084, 0.085, 1.752, -1.271, and 0.725, respectively). A prediction model was constructed based on these independent variables. The weighted average of the overall accuracy in predicting success or failure of version and vaginal delivery was 70.9%. The regression model was then applied to study group B. Using 0.50 as the cutoff value, the sensitivity, specificity, positive, and negative predictive values were 75.4, 58.8, 73.7, and 61.0%, respectively. CONCLUSION: A regression model constructed based on clinical variables failed to provide an accurate predictive tool of successful external cephalic version and vaginal delivery. However, in women who are equivocal about external cephalic version, a high prediction of success would be encouraging.

External cephalic version induced fetal cerebral and umbilical blood flow changes are related to the amount of pressure exerted.

OBJECTIVE: To correlate the applied pressure during external cephalic version with the changes in fetal middle cerebral arterial and umbilical arterial flow before and after the procedure. DESIGN: A prospective observational study over a two-year period. SETTING: External cephalic version was performed in a university hospital. POPULATION: Sixty-nine women with singleton breech-presenting pregnancy at or above 36 weeks of gestation undergoing external cephalic version. METHODS: During external cephalic version, the operator wore a pair of pressure-sensing gloves which had thin piezo-resistive sensors positioned on the palmar surface. During each version procedure, real-time pressure readings were recorded from all sensors, and then analysed with a computer program. The amount of pressure applied over time was presented by pressure-time integral. The pulsatility indices of both fetal middle cerebral artery and umbilical artery before and after external cephalic version were measured. The changes of pulsatility indices of both middle cerebral artery and umbilical artery were presented as a ratio of the post-external cephalic version pulsatility indices to pre-external cephalic version pulsatility indices, denoted by middle cerebral artery pulsatility index ratio and umbilical artery pulsatility index ratio, respectively. The statistical correlation between pressure-time integral and middle cerebral artery pulsatility index ratio and umbilical artery pulsatility index ratio are analysed using Pearson's correlation test. MAIN OUTCOME MEASURES: Changes in pulsatility indices of fetal middle cerebral and umbilical arteries and fetal heart rate after external cephalic version. RESULTS: The overall success rate of external cephalic version was 77%. There was a significant negative correlation between pressure-time integral and both middle cerebral artery pulsatility index ratio (P= 0.001) and umbilical artery pulsatility index ratio (P= 0.012). When women were categorised according to placental site, pressure-time integral was negatively correlated with middle cerebral artery pulsatility index ratio only when the placenta was posteriorly located (P= 0.003), and with umbilical artery pulsatility index ratio only when the placenta was laterally located (P= 0.03). CONCLUSIONS: The greater the force applied during external cephalic version, the greater the reduction in pulsatility indices of middle cerebral artery and umbilical artery, indicating an increase in blood flow through these arteries. The increase in cerebral blood flow after external cephalic version is more prominent when the placenta is lying posteriorly, while the increase in umbilical flow is more prominent when the placenta is lying laterally. These findings suggest that the vascular changes probably represent a direct effect of force exerted on the fetal head and the placenta.

Cord blood acid-base status at delivery after successful external cephalic version.

BACKGROUND: This study was designed to evaluate whether cord blood acidosis is more likely in infants born after successful external cephalic version. METHODS: This retrospective cohort study included 89 singleton deliveries with successful version performed over a 2-year period. Their cord blood acid-base parameters were compared to 89 pregnancies with spontaneous cephalic presentation (control group). RESULTS: There was no significant difference between the version and control groups in birthweight and Apgar scores. There was no difference between the version and control groups in cord arterial pH (7.26 vs. 7.26), arterial pCO(2) (7.04 vs. 7.09 kPa), arterial pO(2) (2.34 vs. 2.59 kPa), arterial base excess (-5.59 vs. -5.64 mmol/L), venous pH (7.32 vs. 7.33), venous pCO(2) (5.73 vs. 5.63 kPa), venous pO(2) (3.86 vs. 3.84 kPa), or venous base excess (-5.03 vs. -5.12 mmol/L). There was also no significant difference in the number of fetuses with cord arterial pH <7.20 between the two groups. CONCLUSION: Neonates delivered after successful external cephalic version are not more likely to be born with acidosis. Our study provides further support for the safety of external cephalic version for term breech pregnancies.

Quantification of contact surface pressure exerted during external cephalic version.

BACKGROUND: The amount of force exerted on the uterus and fetus during external cephalic version (ECV) may be associated with fetal effects or complications. We have designed an instrument to quantify the contact pressure exerted during the performance of ECV, as an indirect measurement of the applied force. METHODS: We have designed a pair of custom-made gloves. Each glove contains 16 piezo-resistive sensors positioned on the palmer surface of the fingers, thenar and hypothenar areas. Pressure readings were recorded simultaneously from all sensors every 0.22 s during each version procedure. Each recording was analyzed with a computer program written according to specified algorithms to ascertain the number of attempts in a version operation, and the duration and pressure changes of each attempt during the operation. RESULTS: Ten subjects having a singleton breech presentation at term underwent an operation of ECV. The number of attempts of version in each operation ranged from one to four. The median pressure-time integral and the duration of an attempt were 19,227 mmHg s (range 5089-42,597 mmHg s) and 42.5 s (range 11.9-80.3 s), respectively. The median pressure-time integral of a whole version operation was 38,110 mmHg s (range 5089-107,511 mmHg s). Subjects with a failed version operation received a higher pressure-time integral (p < 0.05). The number of attempts of each operation was accurately identified by the program. CONCLUSIONS: Measurement of force applied during ECV can be quantified indirectly in terms of contact surface pressure. The indirect measurement of the applied force may further improve the safety of this procedure by preventing excessive use of force by the operator.

Pitfalls in diagnosis of interstitial pregnancy.

BACKGROUND: To determine the incidence and reasons for misdiagnosis in interstitial ectopic pregnancy. METHODS: We conducted a retrospective study from 1990 to 2001. Women with interstitial pregnancy were identified and their case records retrieved and reviewed. Reasons for delay in diagnosis and associated morbidity were recorded. RESULTS: Thirty-six women were diagnosed as having interstitial pregnancy during the study period. Initial diagnosis was incorrect in 15 cases (41.7%). In 14 cases, the interstitial pregnancies were mistaken as intrauterine pregnancy. These misdiagnoses resulted in six inappropriate surgical procedures (evacuation of uterus) being performed and led to rupture of interstitial pregnancy in eight women. In two women, the interstitial pregnancy was mistaken as normal intrauterine pregnancy while the uterus itself was thought to be a cervical fibroid. In both cases, the interstitial pregnancies ruptured at 18-20 weeks of gestation. CONCLUSION: Despite advances in sonographic skills and equipment and the availability of beta-human chorionic gonadotropin (hCG) monitoring, misdiagnosis of interstitial pregnancy still occurs frequently. Clinicians should be aware of the limitations of various investigations and maintain a high index of suspicion.

Large choledochal cyst present through 2 pregnancies. A case report.

BACKGROUND: Choledochal cyst is rarely diagnosed during pregnancy, and it is very difficult to make a diagnosis of it clinically or radiologically. CASE: A woman was diagnosed as having an ovarian cyst and gallbladder mucocele on ultrasonography in both her first and second pregnancies. She was asymptomatic, and conservative management was adopted. Three days after delivery of her second child, the patient had a sudden onset of right upper quadrant pain associated with deranged liver function. Emergency laparotomy revealed a type I choledochal cyst with evidence of infection. Excision of the cyst, cholecystectomy and bilateral hepatojejunostomy in the Roux-en-Y fashion were performed. CONCLUSION: A choledochal cyst in pregnancy is difficult to diagnose and poses a threat to mother and fetus.

High incidence of obstetric interventions after successful external cephalic version.

OBJECTIVE: To investigate the delivery outcome after successful external cephalic version (ECV). DESIGN: Case-control study. SETTING: University teaching hospital. POPULATION: The study group consisted of 279 consecutive singleton deliveries at term over a six-year period, all of which had had successful ECV performed. The control group included 28,447 singleton term deliveries during the same six-year period. METHODS: Between group differences were compared with the Mann-Whitney U test or Student's t test where appropriate. Odds ratio and 95% confidence interval (CI) were calculated for categorical variables. Main outcome measures Incidence of and indications for obstetric interventions. RESULTS: The risk of instrumental delivery and emergency caesarean section was higher in the ECV group (14.3% vs 12.8%; OR 1.4; 95% CI 1.0-2.0, and 23.3% vs 9.4%; OR 3.1; 95% CI 2.3-4.1, respectively). The higher caesarean rate was due to an increase in all major indications, namely, suspected fetal distress, failure to progress in labour and failed induction. The higher incidence of instrumental delivery was mainly due to an increase in prolonged second stage. The odds ratio for operative delivery remained significant after controlling for potential confounding variables. There were also significantly greater frequencies of labour induction (24.0% vs 13.4%; OR 2.0; 95% CI 1.5-2.7) and use of epidural analgesia (20.4% vs 12.4%; OR 1.8; 95% CI 1.4-2.4) by women in the ECV group. The higher induction rate is mainly due to induction for post term, abnormal cardiotocography (CTG) and antepartum haemorrhage (APH) of unknown origin. CONCLUSION: The incidence of operative delivery and other obstetric interventions are higher in pregnancies after successful ECV. Women undergoing ECV should be informed about this higher risk of interventions.