The effect of ascorbic acid during biopsy and cryopreservation on viability of bovine embryos produced in vivo.

Multiple ovulation embryo transfer (MOET) is used to make more rapid progress in animal breeding schemes. On dairy farms, where female calves are more desired, embryo sex diagnosis is often performed before embryo transfer. Fresh transfers have been favored after biopsy due to cumulative drop in pregnancy rates following cryopreservation. The aim of this study was to explore whether exposure to ascorbic acid (AC) during biopsy and freezing increases the viability of biopsied embryos after cryopreservation. Data on presumptive pregnancy and calving rates of biopsied and cryopreserved/overnight-cultured embryos were gathered. Results showed differences in presumptive pregnancy rates between the groups: 45% for both biopsied-cryopreserved groups (control and AC), 51% for biopsied-overnight-cultured embryos and 80% for intact-fresh embryos. Differences between the groups were also apparent in calving rates: 22% for biopsied-cryopreserved control embryos, 31% for biopsied-cryopreserved AC-embryos, 23% for biopsied-overnight-cultured embryos and 63% for intact-fresh embryos. It is concluded that manipulated embryos are associated with lower presumptive pregnancy and calving rates compared with intact-fresh embryos. The highest calving rates for groups of manipulated embryos were achieved in the AC-group. Therefore, addition of AC can be recommended if biopsy is combined with freezing before transfer.

Impact of in vitro fertilization of bovine oocytes with sex-sorted frozen-thawed spermatozoa on developmental kinetics, quality and sex ratio of developing embryos.

We studied whether bovine embryos developing after in vitro fertilization (IVF) with sex-sorted spermatozoa differed in developmental kinetics, quality and sex ratio from embryos produced with unsorted spermatozoa. Abattoir-derived oocytes were fertilized with X-sorted, Y-sorted or unsorted spermatozoa from a single bull. To evaluate economical use of the sex-sorted spermatozoa, washed spermatozoa from a single straw (2 million spermatozoa) were used to fertilize each batch of collected oocytes without any further isolation steps. Concentration of the unsorted spermatozoa was adjusted accordingly. Fertilizations were assessed by staining sperm asters at 10 hpi and pronuclei at 20 hpi. Embryo development and morphological quality were monitored on days 2, 7, 8 and 9 of the development (IVF = day 0). All embryos were sexed using PCR. Following fertilization, penetration and subsequent cleavage rates were compromised in the X-sorted group compared with the Y-sorted and unsorted groups (penetration: 58.0% vs. 89.8% and 90.0%, cleavage: 65.3% vs. 81.5% and 75.0%). The use of the sex-sorted spermatozoa did not, however, reduce the proportion of transferable embryos (sex-sorted 29.6% vs. unsorted 27.7%) or their quality (quality 1: sex-sorted 36.0% vs. unsorted 19.9%). The Y-sorted spermatozoa produced more transferable embryos of better quality than the X-sorted spermatozoa (days 7-8: 31.9% vs. 26.4%, quality 1: 38.9% vs. 30.6%). On average, out of 10 transferable embryos, nine were of the predicted sex in the X- and Y-sorted spermatozoa groups. These results indicate that low numbers of X- and Y-sorted spermatozoa can be used successfully for female and male embryo production in vitro.

Embryo production from superovulated Holstein-Friesian dairy heifers and cows after insemination with frozen-thawed sex-sorted X spermatozoa or unsorted semen.

The aim of this study was to evaluate embryo production in superovulated Holstein-Friesian dairy heifers and cows inseminated with either X-sorted spermatozoa (2 million/dose) or unsorted semen (15 million/dose). Experiment 1 at the research farm involved eight heifers, six cows and semen of one Holstein bull. All transferable embryos were diagnosed for sex. Experiment 2 included embryo collections on commercial dairy farms: X-sorted spermatozoa from three Holstein bulls were used for 59 collections on 28 farms and unsorted semen from 32 Holstein bulls were used for 179 collections on 79 farms. Superovulations were induced by eight declining doses of FSH (total of 12 ml for heifers and 19 ml for cows) starting on days 8-12 of the estrus cycle. Inseminations began 12h after the onset of estrus and were performed two to four times at 9-15 h intervals. Low-dose X-sorted inseminates were deposited into uterine horns and unsorted semen was placed into the uterine body. In Experiment 1, on average 70.3 and 75.0% of embryos recovered from heifers, and 48.4 and 100% of embryos recovered from cows were of transferable quality in X-sorted and unsorted groups, respectively. The proportion of transferable female embryos produced approximately doubled when insemination was with X-sorted spermatozoa compared to insemination with unsorted semen (heifers 96.4% versus 41.1%; cows 81.1% versus 39.8%). In Experiment 2, estimated 53.9 and 65.5% of embryos recovered from heifers, and 21.1 and 64.5% of embryos recovered from cows were of transferable quality in X-sorted and unsorted groups, respectively. Proportions of unfertilized oocytes were 21.1 and 10.6% for heifers and 56.0 and 14.4% for cows in X-sorted and unsorted groups, respectively. Consequently, cows inseminated with X-sorted spermatozoa produced significantly smaller proportions of transferable embryos (p<0.005) and significantly larger proportions of unfertilized oocytes (p<0.001) than those inseminated with unsorted semen. Proportions of quality 1 or degenerated embryos were similar for the two treatments in both heifers and cows. Within treatments, bulls did not significantly affect the proportions of transferable, unfertilized or degenerated oocytes/embryos. It was concluded that using low-dose X-sorted spermatozoa rather than normal-dose unsorted semen for the insemination of superovulated embryo donors can improve the proportion of transferable female embryos produced but this potential may not be achieved in commercial practice, particularly in cows, because of reduced fertilization rates when using low doses of X-sorted spermatozoa.

Respiration rates of individual bovine in vitro-produced embryos measured with a novel, non-invasive and highly sensitive microsensor system.

Oxygen consumption is a useful parameter for evaluating embryo quality, since it provides a valuable indication of overall metabolic activity. Over the years, several approaches have been used to measure the respiration rates of individual embryos, but a convincing method has not yet been reported. In this study, we introduce and have validated a novel high resolution microsensor technology to determine the respiration rates of individual embryos at different developmental stages. We have employed this technology to investigate the correlation between respiration rate and embryo morphology, diameter and sex. Following morphological evaluation, individual respiration rates of day 3 (n = 18) and day 7 (n = 60) bovine in vitro-produced embryos were determined. Of the measured embryos, 64 were lysed for sex diagnosis by PCR. Average respiration rates of day 7 embryos (1.30 +/- 0.064 nl/h) were 3.4-fold higher than day 3 embryos (0.38 +/- 0.011 nl/h). On day 7, the average respiration rate of quality 1 blastocysts was significantly higher than the respiration rates of the lower qualities. For both day 3 and day 7 embryos, respiration rates were directly influenced by embryo diameter but did not differ between sexes. These results have demonstrated that the novel microsensor technology can be used to accurately and rapidly (8 min) measure the respiration rates of individual embryos at different developmental stages. Respiration rates were only in partial agreement with embryo morphology, suggesting a slight discrepancy between these two methods in assessing embryo quality. It is likely that a combined assessment of embryo respiration and morphology would improve embryo classification and subsequent selection.

Changing incidence and outcome of infants with respiratory distress syndrome in the 1990s: a population-based survey.

AIM: To evaluate the trends in the incidence, clinical course and outcome of respiratory distress syndrome (RDS) in the newborn in the Oulu University Hospital region in northern Finland. METHODS: In the population of 58 990 infants, the incidence rates of RDS specific to gestational age and birthweight in two consecutive periods, 1990-95 and 1996-99, were calculated. Clinical course and other neonatal morbidities were reported. All surviving infants were followed up until 1 y of corrected age. RESULTS: The overall incidence of RDS did not change significantly (8.7/1000 livebirths in 1990-95 vs 7.6 in 1996-99; p = 0.15), but the gestational age-adjusted incidence decreased between the two consecutive periods (p = 0.005). The frequency of infants with gestational age below 28 wk tended to increase towards the late 1990s, while their RDS incidence remained unchanged. RDS-related neonatal mortality decreased in parallel with neonatal mortality, accounting for 15% of all neonatal deaths. The duration of oxygen therapy shortened (8.0 vs 5.5 d) and the incidence of pneumothorax decreased (9.7 vs 4.1%), whereas the rate of chronic lung disease at 36 wk of postconceptional age (16.4 vs 16.7%) and at 1 y of corrected age (9.2 vs 8.2%) remained unchanged, as did also associated neurosensory morbidity (8.8 vs 9.5%). CONCLUSION: During the 1990s, the incidence of RDS shifted towards more immature infants and the gestational-age specific incidence decreased. The course of the disease shortened and acute complications decreased. The frequency of chronic pulmonary sequelae (and associated neurosensory morbidity) at the age of 1 y did not change significantly.

Combination of cervical interleukin-6 and -8, phosphorylated insulin-like growth factor-binding protein-1 and transvaginal cervical ultrasonography in assessment of the risk of preterm birth.

OBJECTIVE: To determine the value of combinations of cervical interleukin-6 (IL-6), cervical interleukin-8 (IL-8), the phosphorylated isoform of insulin-like growth-factor binding protein-1 (IGFBP-1), and cervical ultrasonography in the prediction of preterm birth. DESIGN: Prospective follow up. SETTING: Oulu University Hospital maternity clinic from February 1997 to July 1998. POPULATION: Women with singleton pregnancies (n = 77), referred from outpatient clinics at 22-32 weeks of gestation with symptoms (uterine contractions) or signs (cervical change) of threatened preterm birth. Symptomless women (n = 78) matched for gestational age, parity and maternal age at recruitment were studied as a reference group. METHODS: A urine sample for bacterial culture was collected, and cervical swab samples for assays of interleukin-6 and -8 and phoshorylated IGFBP-1 were taken before digital cervical examination. A Pap smear for analysis of bacterial vaginosis and samples for analysis of chlamydia and streptococci were also obtained. Cervical measurements were made by transvaginal ultrasonography. The same sampling and cervical measurement were repeated twice at two-week intervals. The cutoff values of the markers were determined by receiver-operating characteristic curve analysis. MAIN OUTCOME MEASURE: Preterm birth (<37 weeks). RESULTS: The preterm birth (<37 weeks) rate for women in the study group was 16% (12/77). The cervical interleukin-6 cutoff value (61 ng/L) at first visit had a sensitivity of 73% and a specificity of 61% in predicting preterm birth, with a positive likelihood ratio (LR+ ) of 1.9 (95% CI 1.2-3.0). An ultrasonographically measured cervical index value of > 0.36 at recruitment predicted preterm birth in 25% (5/20) of the study group compared with 9% (5/54); LR+ 2.2 (95% CI 1.03-4.7). Cervical phosphorylated IGFBP-1 > 6.4 microg/L [LR+ 1.8 (95% CI 0.7-2.9)], interleukin-8 > 3739 ng/L [LR+ 1.4 (95% CI 0.9-2.4)], and ultrasonograpic cervical length < 29.3 mm [LR+ 2.7 (95% CI 0.8-9.7)] increased the risk of preterm birth. According to the logistic regression model, a combination of IL-6, and IL-8 and cervical index increased the specificity to 97%, but the sensitivity fell to 30% in detecting preterm birth. There was a significantly increased incidence of puerperal infections if phosphorylated IGFBP-1 concentrations were elevated (> 21.0 microg/L), 36% (4/11) compared with 4.6% (3/65), LR+ 6.7 (95% CI 2.7-17), the sensitivity being 67% (4/6) and the specificity 90% (63/70). Elevated phosphorylated IGFBP-1 concentrations (> 21.6 microg/L) were also associated with an increased risk of neonatal infections; LR+ 8.0 (95% CI 3.5-18). CONCLUSIONS: An increase in cervical IL-6 concentration and the ultrasonographically measured cervical index appear to be associated with preterm birth. A combination of these markers with measurement of cervical IL-8 appears to be the best predictor of preterm birth. Neither the sensitivity nor specificity of the tests used in this study are good enough to predict preterm birth for clinical decision making. Cervical phosphorylated IGFBP-1 seems to be a marker of puerperal and neonatal infectious morbidity in cases of threatened preterm delivery, suggesting early tissue degradation at the choriodecidual interface.

Ratio of proliferating cell nuclear antigen-positive nuclei to total cell number is higher in day 7 than in day 8 vitrified in vitro-produced bovine embryos.

The aim of the present study was to find a reliable functional criterion for the evaluation of the proliferation potential of bovine in vitro-produced embryos. We used immunocytochemical detection of proliferating cell nuclear antigen (PCNA) combined with propidium iodide (PI) staining and subsequent confocal laser scanning microscopy together with routine morphological evaluation under a stereomicroscope to study fresh Day 7, 8, and 9, and cryopreserved Day 7 and 8 embryos. The ratio of PCNA/PI-positive nuclei was equal in fresh Day 7 and Day 8 embryos and significantly lower in Day 9 embryos. In general, Day 7 embryos tolerated the cryopreservation treatments better than Day 8 embryos. Vitrification in normal straws was especially detrimental to Day 8 embryos. In fresh Day 7 and 8 embryos, the PCNA results were in agreement with stereomicroscopic evaluation. However, in Day 9 fresh and in Day 7 and 8 treated embryos, the missing PCNA revealed disorders that were not observed under morphological evaluation. PCNA immunocytochemistry is an effective method to obtain information about the functional state of nuclei. The ratio of PCNA-positive nuclei can provide more information and numerical data about the developmental potential of bovine embryos after cryopreservation.

Vaginal clindamycin in preventing preterm birth and peripartal infections in asymptomatic women with bacterial vaginosis: a randomized, controlled trial.

OBJECTIVE: To determine whether treatment of bacterial vaginosis (BV) in early pregnancy decreases the risk of preterm delivery and peripartum infectious morbidity. METHODS: In this multicenter, randomized, double-masked, placebo-controlled intervention trial, screening for BV was performed by vaginal Gram stain obtained from 5432 healthy women with singleton pregnancies during the first antenatal clinic visit at 10--17 weeks' gestation. Bacterial vaginosis-positive women with no past history of preterm delivery were randomized to a single course of treatment with either 2% vaginal clindamycin cream or identical placebo cream for 7 days. Repeat Gram stains were taken 1 week after treatment and at 30--36 weeks' gestation. Preterm delivery was defined as spontaneous delivery before 37 gestational weeks. Peripartum infectious morbidity was defined as postpartum endometritis, postpartum sepsis, postcesarean wound infection, or episiotomy wound infection, necessitating antimicrobial therapy. According to the power analysis, 180 patients were needed for both treatment arms to show a three-fold difference in the rates of preterm births. RESULTS: The overall prevalence of BV was 10.4%. Of all BV-positive women, 375 (66%) were randomized to the treatment arms. The primary cure rate was 66% in the clindamycin group; in the placebo group, 34% spontaneously cleared BV (odds ratio [OR] 1.9, 95% confidence interval [CI] 1.3, 2.8). The rate of preterm deliveries was 5% in the clindamycin group and 4% in the placebo group (OR 1.3, 95% CI 0.5, 3.5). The rate of peripartum infectious morbidity was 11% in the clindamycin group and 18% in the placebo group (OR 1.6, 95% CI 0.9, 2.8). Bacterial vaginosis recurred in 7% of women. The rate of preterm deliveries was 15% in this subgroup compared with 2% among women who remained BV negative (OR 9.3, 95% CI 1.6, 53.5). CONCLUSION: Vaginal clindamycin did not decrease the rate of preterm deliveries or peripartum infections, but recurrent or persistent BV increased the risk for these complications.

A randomised controlled trial of vaginal clindamycin for early pregnancy bacterial vaginosis.

OBJECTIVE: To determine whether treatment of bacterial vaginosis (BV) with vaginal clindamycin affects pregnancy outcome. MATERIALS AND METHODS: Mothers with singleton pregnancies and without previous preterm delivery in 17 health centres in Oulu from March 1996 Until March 1998, in whom BV was diagnosed by Gram stain of a vaginal swab at the first antenatal visit (at the 12th gestational week) were randomised at Oulu University Hospital to have a one-week course of vaginal clindamycin, or placebo. A follow up sample of Gram stain was taken two weeks after randomisation and at the 30th gestational weeks. Pregnancy outcome data was obtained from hospital records. Primary outcome was preterm birth, and puerperal infectious morbidity the other outcome measure. RESULTS: During the study period 1956 women were screened, of whom 143 (7.3%) were BV- positive. One hundred and one were randomised. The total preterm birth rate of BV+ women randomised was 9.9% (10/101). Preterm birth occurred in 20.7% (6/29) vs 0% (0/26) according to whether BV persisted or not (P < 0.01). The preterm birth rate was 13.7% (7/51) in the clindamycin group vs 6.0% (3/50) in the placebo group (OR 2.5, 95% CI 0.6-10). BV was cured just after treatment in 17 out of 51 (33%) of the clindamycin- treated patients vs 17 out of 50 (34%) of the placebo- treated patients (OR 1.0, 95% CI 0.4-2.2). There was a difference in puerperal infectious morbidity in patients where BV persisted (31%, 9/29) compared with those in which BV did not persist (7.7%, 1/26) (OR 5.4, 95% CI 1.04-28). Infections were seen in 4/51 (8%) of the clindamycin treated vs 10/50 (20%) of the placebo treated cases, (OR 0.3, 95% CI 0.1-1.2). CONCLUSION: The prevalence of BV was lower than expected in this low risk population, but nevertheless it increased the risk of preterm birth and puerperal infectious morbidity, the risk being highest in cases where BV persisted during pregnancy. Vaginal clindamycin treatment for BV in the first trimester of pregnancy did not appear to reduce the risk of preterm birth or puerperal infections.

Preterm delivery for maternal or fetal indications: maternal morbidity, neonatal outcome and late sequelae in infants.

OBJECTIVE: To assess maternal morbidity, and neonatal outcome and especially long term sequelae in infants born preterm due to maternal or fetal indications. DESIGN: Analysis of retrospective cohort. SETTING: Oulu University Central Hospital, Finland. POPULATION: One hundred and three women, who were between the 24th and the 33rd week of pregnancy, delivered by caesarean delivery because of maternal or fetal indications. They were matched with 103 women who had spontaneous preterm delivery at corresponding gestational weeks between 1990-1997. MAIN OUTCOME MEASURES: Maternal morbidity, reasons for caesarean delivery, neonatal mortality and morbidity rates, and later development of the infants. RESULTS: Pre-eclampsia was diagnosed in 57% of the women in the indicated group and only in one woman in the control group. All infants in the indicated group and almost a third in the control group were born by caesarean birth; the main indication was threatening fetal asphyxia. There was a significant difference in neonatal mortality rates between the groups (175 vs 78 per thousand live births in the indicated vs control infants; RR 2.3, 95% CI 1.02, 4.9) and the main cause of death was respiratory insufficiency: 64% in the indicated group and 22% in the controls; RR 2.9, 95% CI 0.8, 10. Respiratory distress syndrome occurred more often (73% vs 53%, RR 1.4, 95% CI 1.1, 1.7) and it was more severe and more complicated in infants in the indicated group, compared with those in the control group. Symptomatic chronic lung disease at one year of age was more common in infants in the indicated group than in the control group (15% vs 3%; RR 4.6, 95% CI 1.4, 15.9). CONCLUSIONS: Not only the risks of neonatal mortality and morbidity but also long term pulmonary consequences, appear to be greater in infants born preterm by indicated delivery than in preterm infants born spontaneously at corresponding weeks.

Perinatal and neonatal outcome and late pulmonary sequelae in infants born after preterm premature rupture of membranes.

OBJECTIVE: To evaluate fetal outcome and long-term impact of very early preterm premature rupture of membranes (PROM). METHODS: In a retrospective cohort study, 78 women with singleton pregnancies who delivered at the Oulu University Central Hospital between 1990 and 1996 and who had early PROM, between the 17th and 30th gestational weeks, were matched with 78 women with spontaneous preterm delivery during the same time (control group). The main outcome measures were maternal morbidity, interval from early PROM to delivery, perinatal and neonatal mortality rates and neonatal morbidity, need for primary and recurrent hospitalization and later pulmonary complications of the infants, and growth and neurologic findings at 1 year of corrected age. RESULTS: The perinatal mortality was 282 per 1000 births in the early PROM group and 256 per 1000 births in the control group. Histopathologically defined chorioamnionitis and puerperal infections were significantly more common in the early PROM group than in controls (51 versus 29%, odds ratio [OR] 2.5, 95% confidence interval [CI] 1.3, 4.9 and 38 versus 22%, OR 2.3, 95% CI 1.1, 5.1, respectively). There were no differences in neonatal infections between groups. Pulmonary hypoplasia was detected more often in the early PROM group (in nine infants) compared with the control group (no infants). The duration of rehospitalization up to 1 year of age due to respiratory problems was a mean of 5 days in the early PROM group and a mean of 1 day in the control group (P = .01; 95% CI 0.9, 6.9). Symptomatic chronic lung disease at 1 year of age was detected more often in the early PROM group than in controls (22 versus 9%; OR 2.4, 95% CI 0.9, 6.5). CONCLUSION: Early PROM seems to be a major obstetric and neonatal problem with pulmonary ramifications extending beyond the neonatal period. However, most of these infants can be saved.

The clinical significance of an absent end-diastolic velocity in the umbilical artery detected before the 34th week of pregnancy.

BACKGROUND: The aim of this study was to evaluate the clinical significance of absent or reversed (ARED) flow detected in the late second or early third trimester in the umbilical artery in high-risk pregnancies. METHODS: Eighty-three women with hypertensive disorders of pregnancy, gestational diabetes or a suspected disorder of the fetus (e.g. small-for-gestational age) were included in this retrospective study. A constant finding of ARED flow in the umbilical artery was registered with the pulsed Doppler method between the 23+/-0 and 33+/-6 gestational weeks. Perinatal mortality (PNM) rates, Apgar scores and arterial umbilical pH values, birth weights, the frequency of SGA, gestational ages at birth, NICU (=neonatal intensive care unit) days, anomalic fetuses and the mode of delivery were registered. Mann-Whitney U-test and chi-squared test were used for statistical analysis. RESULTS: The PNM in the entire group under study was 19.3% (16 infants/fetuses). The rate of structurally or chromosomally abnormal fetuses was 15.7% (13 infants/fetuses). When anomalic fetuses were excluded the PNM was 18.6%. No non-anomalic fetuses/newborns were lost in cases in which ARED was detected after the 30th week. No statistically significant difference was observed in PNM and SGA frequencies when comparing AEDV (absent end-diastolic velocity) fetuses with those who had REDV (reversed end-diastolic velocity). When anomalic fetuses were excluded the PNM rate in the AEDV group was 8.9% compared with the PNM rate of 35.7% in the REDV group; (p=0.03). CONCLUSIONS: An early ARED finding (before the 34th week) in the umbilical artery signifies a marked warning signal of fetal distress. In these cases the rates of perinatal morbidity and mortality are very high, which is a reflection of the severity of the condition. The majority of fetuses can, however, be saved.