Francesco Pomini

Cardiopulmonary bypass in pregnancy

The cardiopathic patient can sustain acute heart failure during pregnancy. In such cases, if open heart operation is necessary to save the patients life, the fetus could be seriously compromised after exposure to cardiopulmonary bypass. From 1958 to 1992, 69 reports of cardiac operations during pregnancy with the aid of cardiopulmonary bypass have been published. Maternal mortality was 2.9%. Embryofetal mortality was 20.2%. Examining only the last 40 patients, maternal and embryofetal mortality were 0.0% and 12.5%, respectively. Embryofetal mortality was 24.0% when hypothermia was used, compared with 0.0% while operating in normothermia. Maternal mortality did not change. The use of hypothermia during cardiopulmonary bypass provoked uterine contractions in several patients. Hypothermia decreases O2 exchange through the placenta. Pump flow and mean arterial pressure during cardiopulmonary bypass seem to be the most important parameters that influence fetal oxygenation. We speculate that cardiac operation is not a contraindication to pregnancy prolongation.

The duration of hypertension in the puerperium of preeclamptic women: Relationship with renal impairment and week of delivery

OBJECTIVE The purpose of the study was to determine whether the duration of hypertension in the puerperium of preeclamptic women was related to certain clinical features of disease severity. STUDY DESIGN We studied 269 singleton pregnancies divided into two groups: 159 with gestational hypertension and 110 with preeclampsia. The normalization time of blood pressure in puerperium was estimated as the interval between the delivery day and the first day when each of two to four self-measurements per day of diastolic blood pressure was observed to be < or = 80 mm Hg for at least 3 consecutive days. RESULTS Normalization time was shorter in gestational hypertension than in preeclampsia (6 +/- 5.5 [means +/- SD] vs 16 +/- 9.5, respectively, p < 0.0001). Normalization time of gestational hypertension showed a significant correlation with uric acid (r = 0.20, p < 0.025); normalization time of preeclampsia displayed significant correlations with the week of delivery (r = -0.34, p < 0.005), uric acid (r = 0.34, p < 0.025), and urea nitrogen (r = 0.29, p < 0.025), respectively. After stratification by parity, in both groups the correlations of normalization time with renal data were observed only among multiparous women, whereas in preeclampsia the link of normalization time with the week of delivery remained highly significant in both subgroups. CONCLUSIONS The differences observed between gestational hypertension and preeclampsia suggest that distinct mechanisms or a different maternal answer to the same mechanism(s), in maintaining high blood pressure in puerperium, are present in the two groups. Normalization time might reflect the recovery time of the endothelial damage in preeclampsia.

Activity and expression of 15-hydroxyprostaglandin dehydrogenase in cultured chorionic trophoblast and villous trophoblast cells and in chorionic explants at term with and without spontaneous labor.

OBJECTIVE The aim of this study was to investigate whether any changes occurred at term before and with labor in the 15-hydroxyprostaglandin dehydrogenase messenger ribonucleic acid level and in the 15-hydroxyprostaglandin dehydrogenase activity in cultured chorionic and villous trophoblast cells and in chorionic explants. STUDY DESIGN Twelve placentas (labor group [vaginal delivery], n = 6; nonlabor group [elective cesarean delivery], n = 6) were collected. Chorionic trophoblast and villous trophoblast cells and chorionic disks were obtained, cultured, and incubated with 282-nmol/L prostaglandin F(2)(alpha). Medium was collected to measure the 13,14-dihydro-15-keto metabolite of prostaglandin F(2)(alpha), and the cells and disks were snap-frozen to quantify 15-hydroxyprostaglandin dehydrogenase messenger ribonucleic acid expression by Northern blot analysis. RESULTS The formation of the 13,14-dihydro-15-keto metabolite of prostaglandin F(2)(alpha) was significantly lower in the labor group than in the nonlabor group for both sets of cultured cells and for chorionic explants. 15-Hydroxyprostaglandin dehydrogenase messenger ribonucleic acid expression was lower in the chorionic trophoblast cells and chorionic disks of the labor group than those of the nonlabor group. However, the 15-hydroxyprostaglandin dehydrogenase messenger ribonucleic acid level in the villous trophoblast cells did not differ between the labor and nonlabor groups. CONCLUSION Prostaglandin metabolic activity in the chorion is reduced significantly at the time of labor.

Pregnancy outcome in women with cardiac valve prosthesis

Twenty-one pregnancies in 16 women who conceived after cardiac valve replacement were reviewed. Oral anticoagulants were discontinued before conception or as soon as possible for subcutaneous heparin treatment (8000-14,000 IU every 8-12 h) and resumed in the second trimester until the last period of pregnancy when oral anticoagulants were replaced again by heparin. No therapeutic abortion was performed. The spontaneous abortion rate was found to be 14.3% (3/21). Preterm delivery (< or = 37 weeks) and low birth weight babies (< 2500 g) were 29.4% (5/17) and 35.3% (6/17), respectively, significantly more frequent than those of the control group (P < 0.02 and P < 0.0005). No significant statistical difference was found when the rate of spontaneous abortion [14.3% (3/21)] and the rate of fetal growth retardation [11.8% (2/17)] were compared with the control group. The majority of thromboembolic events (6/7) occurred during heparin regimen in three mothers; one of them subsequently died. No coumarin embryopathy was observed and the physical and mental development in the 16 surviving children was good. This study confirms: (1) the increased rate of preterm delivery and infants weighing < 2500 g; (2) the increased risk of maternal thrombosis related to heparin use; and (3) the good follow-up in the surviving children.

Doppler velocimetry and cytofluorimetric analysis in uterine myomas

Background: To correlate resistance indices (RI) of vessels detected by transvaginal Doppler velocimetry to the proliferative fraction (PF) calculated by flow cytometry in uterine myomas. A prospective study was carried out on patients scheduled for surgery because of symptomatic uterine myomas. A group of 26 myomas characterized by the presence of detectable vessels at Doppler analysis in the inner part of the mass were included in the study. Methods: The day before surgery patients were studied with both conventional and color Doppler ultrasonography. The volume of the myoma was recorded. The lowest value of RI obtained by Doppler analysis of the vessels within the myoma was considered for the study. Samples from myomas were processed and analyzed by flow cytometry. A PF, representing the cumulative frequency of cells in the S and G2/M phases of the cell cycle, was considered for the analysis. Results: No statistically significant correlation was observed between RI and PF (r = 0.06, p = 0.74). Regression analysis of the intratumoral RI values on the volume of the myoma showed a significant negative correlation (r = –0.46, p = 0.012). Conclusions: Preoperative Doppler evaluation of uterine myomas did not provide predictive information of the proliferative status of the neoplasm. A significant correlation was found between the volume of the myoma and RI.

An Experimental Animal Model of Intestinal Obstruction to Simulate in utero Therapy for Jejunoileal Atresia

Objective: To obtain ‘intestinal atresia-like’ conditions in the fetal lamb model to subsequently allow in utero surgical repair. Methods: Six time-dated pregnant sheep underwent general anesthesia at 75 days of gestation (term 145 ± 5 days). After maternal laparotomy and hysterotomy, the fetal abdomen was opened. Once the jejunoileal intestinal loop was identified, the mesenteric vessels were isolated, ligated, and sectioned in 2 fetuses, and in the remaining 5 fetuses the bowel loop was ligated. Two further fetuses were used as controls and underwent sole laparotomy. Of the group of 7 fetuses 2 were reoperated at 100–105 days of gestational age and underwent intestinal recanalization. Eight fetuses were delivered at term by cesarean section and the remaining 1 by spontaneous delivery. One newborn underwent neonatal entero-enteric anastomosis. Results: 4 out of 6 fetuses survived, in utero intestinal or vascular ligation having provoked an ‘intestinal atresia-like’ picture. The animal operated at birth died. The 2 control fetuses and the 2 fetuses with in utero intestinal recanalization survived until term. Conclusion: The present study shows that in utero treatment of intestinal obstruction is possible in an experimental model.

Hypothetical Role of Prostaglandins in the Onset of Preterm Labor after Fetal Surgery

Preterm labor is one of the most important factors limiting the advancement of fetal surgery programs. While prostaglandins (PGs) have long been indicated as the key factor in the initiation of labor in humans, there is significant evidence showing that the chorionic membrane acts as a powerful barrier between the decidua/myometrium and amniotic PGs during normal pregnancy. After either open or endoscopic fetal surgery the imperfect, non-hermetical closure of the chorion permits leakage of PGs from the amnionic sac, allowing them to reach the decidua and myometrium. The surgical wound in the chorionic barrier could be the major factor involved in preterm labor and delivery after human fetal surgery.