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Objective: To examine the contribution of singleton, cephalic, term (37 weeks or later) nulliparous cesarean rates to overall cesarean incidence in a single institution during a 35-year period., Methods: Cesarean rates were examined for 1974, 1984, 1994, 1999, 2005, and 2008, applying a 10-group classification system. Groups 1 (spontaneously laboring, term nulliparous women) and 2 (prelabor cesarean and induced term nulliparous women) were combined as a composite variable-the term, singleton, cephalic nulliparous woman., Results: Overall and term, singleton, cephalic nulliparous cesarean rates correlated throughout the 35-year period (r=0.93, P<.001). Between 1974 and 2008, overall cesarean rates increased from 5% to 19.1% and from 4.4% to 15.8% among term, singleton, cephalic nulliparous women. Term, singleton, cephalic nulliparous inductions increased from 19.7% to 32.7% (P<.001) and the intrapartum cesarean rate in term, singleton, cephalic nulliparous inductions rose from 4.1% to 27.3%. The cesarean rate in group 1 increased from 2.3% to 7.2%., Conclusion: The increase in term, singleton, cephalic nulliparous cesarean rates correlated with the increase in overall cesarean rates throughout 35 years in an institution with standard management of labor. This relationship was due to an increase in both the incidence and rate of cesarean delivery within term, singleton, cephalic nulliparous inductions. Examination of the different term, singleton, cephalic nullipara components (spontaneous labor, induction, or prelabor cesarean) can help to identify major variations in practice between institutions., Level of Evidence: III.

Objective: Our aim was to estimate the obstetric outcome of second delivery in women with normal glucose tolerance whose first fetus was macrosomic (fetal weight >/= 4,500 g)., Methods: Primiparas delivering a macrosomic infant during the years 1997-2000 were identified from a hospital computer database, and the obstetric outcome of a second delivery was analyzed up until June 2003. A control group (birth weight 3,000-3,500 g) served for comparison., Results: Among 13,020 first pregnancies, 301 (2.3%) were macrosomic. A similar proportion in the macrosomic group, 156 of 301 (52%), and control group, 171 of 300 (57%), returned for second delivery (P = .252). Compared with controls, first macrosomic deliveries were characterized by higher rates of operative delivery, anal sphincter injury, and shoulder dystocia. At second delivery, 32% of neonates in the macrosomic group and 0.3% in the control group weighed 4,500 g or more (P < .001). More prelabor cesareans were performed in the macrosomic group compared with controls (27 of 156, 17.3%, compared with 8 of 171, 4.7%; P < .001). Among 104 women in the macrosomic group who labored after first vaginal delivery, 99% (103 of 104) delivered vaginally again compared with 44% (11 of 25) who labored after primiparous cesarean delivery (P < .001), which compares with 97% (146 of 150) and 77% (10 of 13), respectively, in the control group., Conclusion: Despite a one-third recurrence of macrosomia, first vaginal delivery of a macrosomic infant was associated with a high incidence of second vaginal delivery. Conversely, primiparous macrosomic cesarean delivery conveyed a high risk (56%) for repeat intrapartum cesarean whether macrosomia recurred or not., Level of Evidence: II-2.

Objective: To examine the obstetric and perinatal outcome of pregnancies with singleton breech presentation at term when selection for vaginal delivery was based on clear prelabor and intrapartum criteria., Methods: The outcomes of all pregnancies with a breech presentation after 37 weeks of gestation were retrospectively reviewed from January 1997 to June 2000. Criteria for prelabor cesarean or trial of vaginal breech delivery included type of breech, estimated fetal weight (more than 3,800 g), maternal preference, and gestation more than 41 weeks. An intrapartum protocol excluded induction and oxytocin augmentation of labor, combined with a low threshold for cesarean delivery for dystocic labor; an experienced obstetrician was in attendance during labor and delivery., Results: Of 641 women, 343 (54%) underwent prelabor cesarean, and 298 (46%) had a trial of vaginal delivery, of whom 146 (49%) delivered vaginally. Significantly fewer nulliparas (58 of 158, 37%) than multiparas (88 of 140, 63%; P <.001) achieved vaginal delivery after trial of labor. Significantly more infants weighing more than 3,800 g were selected for prelabor (87 of 343, 25%) and intrapartum (31 of 152, 20%) cesarean than delivered vaginally (15 of 146, 10%). Two neonates (0.7%) had Apgar scores of less than 7 at 5 minutes; both were neurologically normal at 6 weeks. There were no nonanomalous perinatal deaths and no cases of significant trauma or neurological dysfunction; 3 infants delivered vaginally died due to lethal anomalies., Conclusion: Safe vaginal breech delivery at term can be achieved with strict selection criteria, adherence to a careful intrapartum protocol, and with an experienced obstetrician in attendance. Our protocol effectively selects larger infants for cesarean delivery., Level of Evidence: II-2

Objective: To evaluate the influence of intrapartum persistent occiput posterior position of the fetal head on delivery outcome and anal sphincter injury, with reference to the association with epidural analgesia., Methods: We conducted a prospective observational study of 246 women with persistent occiput posterior position in labor during a 2-year period, compared with 13,543 contemporaneous vaginal deliveries with occiput anterior position., Results: The incidence of persistent occiput posterior position was significantly greater among primiparas (2.4%) than multiparas (1.3%; P <.001; 95% confidence interval 1.4, 2.4) and was associated with significantly higher incidences of prolonged pregnancy, induction of labor, oxytocin augmentation of labor, epidural use, and prolonged labor. Only 29% of primiparas and 55% of multiparas with persistent occiput posterior position achieved spontaneous vaginal delivery, and the malposition was associated with 12% of all cesarean deliveries performed because of dystocia. Persistent occiput posterior position was also associated with a sevenfold higher incidence of anal sphincter disruption. Despite a high overall incidence of use of epidural analgesia (47% versus 3%), the institutional incidence of persistent occiput posterior position was lower than that reported 25 years ago., Conclusion: Persistent occiput posterior position contributed disproportionately to cesarean and instrumental delivery, with fewer than half of the occiput posterior labors ending in spontaneous delivery and the position accounting for 12% of all cesarean deliveries for dystocia. Persistent occiput posterior position leads to a sevenfold increase in the incidence of anal sphincter injury. Use of epidural analgesia was not related to the malposition.

Objective: To document maternal central hemodynamics during the preclinical and clinical phases of nonproteinuric gestational hypertension and preeclampsia., Methods: We conducted a longitudinal study of 400 primigravidas who were monitored throughout pregnancy using Doppler echocardiography. Multinomial logistic regression was used to identify variables associated with risk of hypertension., Results: Gestational hypertension developed in 24 women and preeclampsia developed in 20. Compared with normotensive controls, women who had preeclampsia had significantly elevated cardiac outputs before clinical diagnosis, but total peripheral resistance was not significantly different during this latent phase. During the clinical phase of preeclampsia, there was a marked reduction in cardiac output and increase in peripheral resistance. All women who had gestational hypertension had significantly elevated cardiac outputs before and during the clinical course of the condition., Conclusion: Our data support the concept of a hyperdynamic disease model for preeclampsia, with a subsequent hemodynamic crossover to low cardiac output and high resistance circulation coinciding with the onset of the clinical syndrome. Women with gestational hypertension had no such hemodynamic crossover and maintained hyperdynamic circulation throughout pregnancy.

Objective: To identify the obstetric factors relating to anal sphincter injury at first vaginal delivery by prospective cohort study of primiparous women., Methods: We compared the results of a bowel function questionnaire and anal vector manometry before and 6 weeks after delivery in 184 primiparous women. Postpartum, pudendal nerve conduction latency was measured in all women, and anal endosonography was performed in 81 with altered fecal continence or abnormal physiology., Results: Sixteen (9%) women, none of whom had altered fecal continence, were delivered by cesarean. After vaginal delivery, 42 of 168 (25%) women had impairment of fecal continence and 76 of 168 (45%) women had abnormal anal physiology. Instrumental vaginal delivery was associated with an 8.1-fold (95% confidence interval [CI] 2.7, 24.0; P < .001) risk of anal sphincter injury and a 7.2-fold (95% CI 2.8, 18.6; P < .001) risk of symptoms. Duration of the second stage of labor beyond 60 minutes led to a 1.7-fold (95% CI 1.14, 2.48; P;< .01) risk of anal sphincter injury and a 1.6-fold (95% CI 1.03, 2.6, P = .01) risk of symptoms. Epidural analgesia, used in 58% of vaginal deliveries, prolonged the second stage of labor (P = .004; odds ratio [OR] 7.7; 95% CI 4.0, 14.7) and was associated with increased risk of sphincter injury (P = .02; OR 2.1; 95% CI 1.1, 4.0) and of symptoms (P = .02; OR 2.0; 95% CI 1.1, 3.7)., Conclusion: Instrumental delivery and a second stage of labor prolonged by epidural analgesia are the obstetric factors that pose the greatest risk of injury to the anal sphincter mechanism in primiparous vaginal delivery.

Objective: To examine the outcome of trial second labor after a first cesarean performed because of cephalopelvic disproportion, defined according to strict diagnostic criteria., Methods: Obstetric details of nulliparous women delivering at 37 or more weeks' gestation by cesarean for cephalopelvic disproportion, between 1975 and 1990, were recorded prospectively. The diagnostic criteria for cephalopelvic disproportion were cervical dilation arrested after 5 cm, unresponsive to oxytocin augmentation, after active dilatation of 2 cm or more in 2 hours. Fetal malpresentations and malpositions were excluded. The outcome of next delivery in our hospital by each woman enrolled was then examined., Results: Eighty-four of 42,793 women met the criteria for disproportion, and 40 with cephalic presentations delivered their next baby in our hospital. All 40 underwent a trial of labor and 27 (68%) delivered vaginally, comprising seven (47%) women with larger second and 20 (80%) with smaller second babies. Of 15 women previously delivered by cesarean at full dilatation, 11 (73%) delivered vaginally with no serious maternal or neonatal morbidity., Conclusion: The strictly defined diagnosis of nulliparous cephalopelvic disproportion should not constitute an automatic "recurrent" indication for elective cesarean delivery, because 68% of patients in our series had successful vaginal deliveries in their next pregnancies. This rate is similar to those reported after all nulliparous cesareans for dystocia.

Objective: Cesarean delivery has been thought to prevent all obstetric anal sphincter damage. The objective of this study was to determine the relationship between the timing of cesarean during primiparous delivery and injury to the anal sphincter mechanism., Methods: A prospective observational study was conducted, using a continence questionnaire and anorectal physiology assessment before and six weeks after primiparous delivery. A cohort of 234 women were recruited from the antenatal clinics at the National Maternity Hospital, Dublin. Thirty-four women delivered subsequently by cesarean, and 200 women by spontaneous vaginal delivery., Results: Thirty-four women underwent cesarean delivery without attempted vaginal delivery: eight prior to labor and 26 during labor, 17 in early labor (cervical dilatation less than 8 cm) and 9 in late labor (dilatation greater than 8 cm). No woman delivered by cesarean had altered fecal continence postpartum. Anorectal physiology was unaltered in women delivered by elective cesarean or cesarean in early labor. Pudendal nerve terminal motor latency was prolonged, anal squeeze pressure increment reduced, but vector symmetry index was unchanged in women delivered by cesarean delivery late in labor, indicating neurologic injury to the anal sphincter mechanism., Conclusion: Cesarean delivery performed in late labor, even in the absence of attempted vaginal delivery, does not protect the anal sphincter mechanism.

Three cases of trisomy 18 are described, each with evidence of diminished fetoplacental function, specifically reduced 24-hour maternal urinary estrogen. All three infants died within three months and showed gross and microscopic evidence of hypoplasia of the fetal adrenal cortical zone. This abnormality is consistent with and helps explain the increased incidence of obstetric intervention and prolonged pregnancy in this syndrome.

Seventeen patients treated with clomiphene citrate were examined using real-time ultrasound timing 28 ovulatory cycles to determine the pattern of follicular development under clomiphene stimulation. The rate of growth was faster, but the follicular diameter range at ovulation was similar to that during spontaneous cycles. This information was used to time midcycle human chorionic gonadotropin (hCG) administration in over 97 cycles in 21 patients responsive to clomiphene who had not conceived. When hCG was given when the mean follicular diameter reached 18 mm, 92% of these cycles were ovulatory. Fourteen patients (67%) conceived within 6 ovulatory treatment cycles. Five of 7 patients (71%) who did not conceive were found to have endometriosis at laparoscopy. Midcycle cervical scores were significantly lower in clomiphene-treated as compared with spontaneous ovulatory cycles, and additional treatment with ethinyl estradiol did not effect a significant improvement. Timing of midcycle hCG using ultrasound is an effective method of inducing ovulation in patients in whom an estrogenic follicular response without ovulation is obtained with clomiphene treatment.

Serial ultrasound examinations were performed every three to five days to monitor 200 singleton pregnancies with gestations of 42 weeks or longer. Scanning was used to measure the deepest amniotic fluid pool and to grade placental echogenic changes. Oligohydramnios, defined as an amniotic fluid pool less than 30 mm, was detected in 33 patients (17%) and was an indication for intervention. Grade III placenta was found in 53 patients (27%), and no grade could be assigned in 13 (7%). Intrauterine growth retardation and meconium-stained or absent amniotic fluid at amniotomy occurred significantly more often in association with oligohydramnios than with grade III placenta, which was found before spontaneous labor in only 24% of cases. Ultrasound placental grading appears to offer little useful additional information to amniotic fluid quantitation in satisfactory monitoring of prolonged pregnancies.

Serial follicular growth was studied using real-time ultrasound scanning in 26 anovulatory patients in 55 cycles stimulated with exogenous human pituitary gonadotropin (hPG) and human chorionic gonadotropin (hCG). Dosage was monitored with urinary total estrogen estimations. The ultrasound findings were not made known to the attending physician. Forty-four cycles (80%) were ovulatory, and conception occurred in 13. The mean follicular diameter of 17 to 25 mm at ovulation corresponded with the range observed in spontaneous cycles, although the rate of follicular growth was faster with hPG. On the day the ovulatory dose of hCG was given, as determined by the first urinary estrogen value greater than 50 microgram/24 hours, estrogen excretion was similar whether single or multiple follicles of potential ovulatory size were present, but mean follicular diameters were significantly smaller when there was more than 1 follicle. During the last 4 days before ovulation, the mean diameters in conceptual cycles increased from 14.2 mm to 19.7 mm, values similar to those observed in spontaneous cycles, but different growth patterns occurred in some nonconceptual cycles. Ovarian hyperstimulation was identified by ultrasound scan in 4 of 5 cycles before urinary estrogen excretion exceeded the normal range. Although ultrasound scan does not supplant estrogen monitoring, it can assist in the early detection of hyperstimulation, in the more accurate timing of the ovulatory dose of hCG, and in the withholding of hCG when 3 or more ovulations are possible. It is recommended that ultrasound examination be performed in all patients before the ovulation-inducing dose of hCG is given to provide information on the number of follicles that are likely to ovulate and thus avoid conception of more than twins.

A sterile gel containing prostaglandin (PG) E2 (2 mg PGE2 10 ml gel) was instilled vaginally in 65 primigravidas with unripe cervixes to accelerate ripening before planned surgical induction of labor. The patients treated with the gel were compared with 30 similar untreated controls. In the PGE2-treated group a significant improvement on cervical score was achieved before labor began, and 47% began to labor "spontaneously" without further treatment. Both the duration of subsequent labor and the incidence of cesarean section were significantly lower in the PGE2-treated group. There were no unwanted fetal or maternal effects. Pretreatment with intravaginal PGE2 gel reduces the risk of failed induction and provides the mother with an experience similar to spontaneous labor without harming the fetus.

Thirty anovulatory patients, previously unresponsive to clomiphene citrate in standard dosage, were treated with a new incremental method of clomiphene therapy. Clomiphene was given continuously with dosage increments every 5 days, up to a maximum dose of 3750 mg, and ovarian response was monitored with urinary estrogen estimation and with ultrasound. Twenty-one patients (70%) ovulated on this regimen and 8 (27%) conceived; 6 patients who ovulated but did not conceive had other infertility factors. Clomiphene response was associated with a progressive rise in follicle-stimulating hormone, luteinizing hormone, and estrogen excretion; these parameters were unchanged in nonresponders. Side effects of treatment were minimal and only 1 case of hyperstimulation occurred. Preliminary testing with estrogen-amplified gonadotropin-releasing hormone did not differentiate responders from nonresponders. Incremental clomiphene treatment appears to be a less complicated alternative for patients who would otherwise require exogenous gonadotropin therapy.