The New Hampshire Perinatal Program: twenty years of perinatal outreach education.

OBJECTIVE: To describe 20 years of regional outreach education by the New Hampshire Perinatal Program, its interaction with all 26 community hospitals in the state with maternity services and an additional four in adjoining Vermont. STUDY DESIGN: This paper describes educational initiatives responsive to the needs of perinatal physicians and nurses. The core of the program is the transport conference held annually at each referring hospital in which maternal-fetal and infant referrals are discussed. There are additional community hospital-based programs, programs at convenient locations in the region and medical center conferences and skills programs. RESULTS: The program annually awards 10,000 continuing medical education credits (CME) and nursing contact hours. Evaluation and feedback from all participants is encouraged. New Hampshire has one of the lowest perinatal mortality rates in the county, which reflects in part the accomplishments of the program. CONCLUSION: Perinatal outreach education is a shared responsibility of providers in both the academic center and community hospitals and is necessary to ensure optimal care for mothers and infants.

Effect of episiotomy on the frequency of vaginal outlet lacerations.

The effect of midline episiotomy on the incidence and severity of vaginal outlet lacerations in spontaneous vaginal deliveries was studied in a retrospective manner by pairing women with and without episiotomy on the basis of age, parity and infant birth weight. When we controlled these three parameters, the patient with an episiotomy had fewer or less severe lacerations 33% of the time. However, when the episiotomy itself was counted as a laceration in the analysis, the number of patients benefitting from the procedure was reduced to 6%, with the nonepisiotomy patient having fewer lacerations than the episiotomy patient 78% of the time. The results suggest that for purposes of reducing outlet lacerations, the episiotomy should be used less often in spontaneous vaginal deliveries.

Spontaneous abortion among insulin-dependent diabetic women.

A prospective study was undertaken to evaluate the frequency of spontaneous abortion in clinically apparent pregnancies among insulin-dependent diabetic women evaluated prior to pregnancy. The study was done in 132 pregnancies occurring in 91 diabetic women. The spontaneous abortion rate was 30%; 70% of the pregnancies progressed beyond 20 weeks. The abortion rates for Classes B, C, D, and F through RT were 0%, 25%, 44%, and 22%, respectively. Initial serum levels of the beta-subunit of human chorionic gonadotropin above 6000 mIU were usually associated with favorable outcome while levels below 6000 mIU were not predictive of outcome. Data from this study suggest that the risk of spontaneous abortion among insulin-dependent diabetic women may be substantially higher than for the general population. Higher abortion rates were generally associated with more advanced White classification of diabetes. Age at diagnosis was the only factor which showed a significant contribution to the risk of abortion.

Effect of vasoactive intestinal polypeptide on uterine blood flow in pregnant ewes.

Vasoactive intestinal polypeptide has been localized in the uterine vasculature, uterine smooth muscle and the placenta of several species. Vasoactive intestinal polypeptide is a potent uterine vasodilator in nonpregnant sheep and also abolishes spontaneous uterine contractile activity, but the effects of this polypeptide on the uterine vasculature of the pregnant animal is currently unknown. The present experiments were performed in seven late-term pregnant sheep which were chronically catheterized to evaluate the uterine vascular effects of vasoactive intestinal polypeptide. An intra-arterial catheter was placed in a branch of the main uterine artery to allow administration of vasoactive intestinal polypeptide directly into the uterine vasculature. Uterine blood flow was continuously monitored via an electromagnetic flow transducer on both main uterine arteries. Vasoactive intestinal polypeptide infused at the rate of 1 to 30 micrograms/min produced dose-related reductions in uterine blood flow (33% +/- 9% at 30 micrograms/min). This decrease was due to a reduction in systemic arterial blood pressure, since calculated resistance in the uterine vasculature that received the vasoactive intestinal polypeptide did not change significantly. In addition, the contralateral uterine vasculature that did not receive direct intra-arterial infusions of vasoactive intestinal polypeptide showed identical changes. These data suggest that vasoactive intestinal polypeptide produces peripheral vasodilation at doses which have very little uterine effect locally. These data can be interpreted to mean either that high local endogenous production of vasoactive intestinal polypeptide prevents exogenously administered vasoactive intestinal polypeptide from exerting its vascular effects, or that vasoactive intestinal polypeptide is a very weak uterine vasodilator in pregnant ewes. The clarification of these possibilities will require further experimentation.

Effect of bisenoic prostaglandins on the uterine vasculature of the nonpregnant sheep.

The effects of the bisenoic prostaglandins on the uterine vasculature and uterine contractile activity have been evaluated in an unanesthetized chronically catheterized nonpregnant sheep preparation. Changes in uterine blood flow were monitored with electromagnetic flow probes while uterine contractile activity and tone were determined via an intra-uterine balloon connected to a pressure transducer. Prostaglandins A2, D2, E2, and prostacyclin (PGI2) were all found to be vasodilators. PGD2 and PGI2 were much more potent than PGA2 and PGE2 in dilating the uterine vasculature. The prostacyclin breakdown product 6-keto PGF1 alpha, PGF2 alpha, thromboxane B2, and the endoperoxide analogues U44069 and U46619 produced vasoconstriction of the uterine vasculature. Prostaglandins A2, D2 and F2 alpha increased while PGI2 decreased uterine contractile activity. PGF2 alpha also increased uterine tone suggesting that a portion of its vasoconstrictor activity may be due to mechanical compression of the uterine vasculature.

Effect of prostaglandin E2 on cervical compliance in pregnant ewes.

Cervical compliance increases dramatically at parturition in sheep independent of uterine activity. Recently, in vitro production of prostaglandin E2 (PGE2) by the cervix has been shown to increase at parturition. This study investigated the effects of PGE2 on cervical compliance and uterine blood flow in pregnant ewes. Eight animals were chronically instrumented with pressure balloons within the cervical os and amniotic cavity, an electromagnetic flow probe on a uterine artery, and catheters in the maternal cervical os, femoral artery, femoral, uterine, and cervical veins, and fetal hindlimb vein. PGE2 (10 mg) was administered in a water-soluble gel into the cervical os every 4 hours times three doses at least 5 days after surgical preparation (124 to 142 days' gestation). In all eight ewes, cervical compliance increased within 8 to 12 posttreatment hours to levels comparable to that seen at spontaneous parturition. Five of the ewes did not progress into labor; compliance in these ewes returned to baseline 24 to 72 hours after the peak. Uterine blood flow was measured in five ewes during the PGE2 treatment and demonstrated no significant alterations. Maternal cardiovascular and fetal respiratory parameters were monitored throughout the experiment and remained stable. The present data suggest that PGE2 may be an important regulatory of the biochemical and physical changes which occur in the cervix at parturition.

Effects of vasoactive polypeptides on the uterine vasculature.

Estrogen-induced increases in uterine blood flow appear to require de novo protein or polypeptide synthesis. In the present experiments a chronically catheterized nonpregnant sheep preparation was used to determine the uterine vascular effects of vasoactive intestinal polypeptide (VIP), neurotensin, and substance P. These effects were compared to those of bradykinin and the most potent vasodilator prostaglandin, prostacyclin. An intra-arterial catheter was placed in a branch of the main uterine artery to allow administration of the compounds directly into the uterine vasculature. Uterine blood flow was continuously monitored via an electromagnetic flow transducer on the maine uterine arteries. VIP, bradykinin, and prostacyclin were equally potent as vasodilators of the uterine vasculature, while neurotensin and substance P were totally devoid of vasoactivity. Unlike estradiol, bradykinin and VIP produced significant changes in systemic arterial pressure and heart rate, suggesting that these compounds may not have responsible for mediating the uterine vascular response observed after estrogen. However, VIP was a potent uterine vasodilator and was able to totally ablate uterine contractile activity, suggesting that this endogenously occurring polypeptide may be important in regulating uterine hemodynamics and contractile activity.

Comparison of human and sheep chorion laeve permeability to glucose, beta-hydroxybutyrate, and glycerol.

Significant permeability of in vitro human chorion laeve to glucose, glycerol, and beta-hydroxybutyrate (betaOH butyrate) and in vitro sheep chorion leave to glycerol and betaOH butyrate was measured. Diffusion across these tissues of glycerol and betaOH butyrate corresponded to the relative molecular size, charge, and lipid solubility of these compounds. The simple diffusion of glucose across human chorion leave was somewhat reduced by metabolic conversion of this compound during the transfer process. Demonstration of in vitro human placental tissue permeability to ketoacids and glycerol suggests that these compounds cross to the fetus when elevated in the maternal diabetic state.

Relationship of fetal and placental weight in human beings: fetal/placental weight ratios at various gestational ages and birth weight distributions.

Two thousand consecutive deliveries occurring over an 11-month period were studied for fetal and placental (F/P) weight characteristics. Infant and placental weight pairs were analyzed according to their gestational ages and growth categories (AGA, SGA, LGA). Graphs were constructed to depict normal placental weight gain and F/P ratio changes over a wide range of gestational ages (23 to 43 weeks). Mean placental weights and F/P ratios continued to increase through 42 weeks' gestation in the AGA and LGA groups, though placental weight showed no change in the SGA group after 36 weeks. F/P ratio continued to increase in the SGA group and was indistinguishable from that of the other two groups. Fetal and placental weight were linearly related in the total sample as well as in the individual growth categories. However, when F/P ratio was plotted against placental weight, the infants were segregated into three completely distinct curves, depending upon their growth characteristics. A wide range of placental weight and f/p ratios existed within all three infant birth weight groups. When one-minute Apgar scores were considered, infants with F/P ratios of greater than 10.00 had significantly higher risks of an Apgar score of less than 6.

Changes in cervical compliance at parturition independent of uterine activity.

A new animal model has been developed to measure intrinsic changes of cerivcal compliance during spontaneous parturition or exposure to hormonal manipulation. Intermittent measurements of cervical compliance and continous measurements of uterine and cervical pressure were made during the last month of gestation of nine pregnant ewes. Cervical compliance increased abruptly and dramatically during spontanous and dexamethasone-induced parturition. Maternal progesterone supplementation at parturition inhibited uterine contractions but not the increase in cervical compliance, demonstrating the independence of the two events. The cervix was found to contract rhythmically and vigorously with a gradual decrease in activity as parturition approached.