Aflibercept in diabetic macular edema: evaluating efficacy as a primary and secondary therapeutic option

The recent results of Protocol T have illustrated the efficacy of aflibercept in the treatment of diabetic macular edema. It also demonstrated that in patients with poor vision (<6/12), aflibercept offers anatomical and visual advantages over ranibizumab and bevacizumab in the first 12 months of treament. At 2 years, the difference between the three drugs decreased with patients with a better baseline VA (69-78) showing a statistically insignificant advantage for ranibizumab compared with aflibercept.These results were achieved using a pro-re nata (PRN) protocol, which was not previously studied in large phase 3 trials, VIVID and VISTA, that chose to compare the 2.0 mg dose in a monthly and bimonthly regimen. In this review article, we analyzed earlier studies such as DAVINCI and VIVID and VISTA to determine which treatment strategy offers the best results; monthly, bimonthly, or PRN. We also studied the different doses for aflibercept used in DAVINCI to determine which is more effective the 0.5 mg dose or the 2.0 mg dose. In addition, we analyzed the recent data from protocol T with regards to visual and anatomic outcomes to try to determine whether these results concur with previous studies. Finally, we discuss the role of aflibercept as a potential alternative to any diabetic macular edema regimen regardless what the primary drug used is.

Identification of nucleated red blood cells in maternal circulation: a second step in screening for fetal aneuploidies and pregnancy complications

BACKGROUND

Identification of fetal nucleated red blood cells (NRBCs) in maternal circulation can facilitate non-invasive prenatal diagnosis, but technical difficulties still exist. An increase in the number of circulating NRBCs, however, could indicate fetal aneuploidies or pregnancy complications.

MATERIALS AND METHODS

The number of NRBCs was determined from 20 mL peripheral blood in 351 women in the second trimester of pregnancy after isolation by magnetic cell sorting (MACS) with anti-CD71 antibody and identification with May-Grunwald/Giemsa staining.

RESULTS

An average of eight NRBCs (range 1-12) were identified among 282 women with chromosomally normal fetuses. In cases known to carry aneuploid fetuses the mean number was 35 (range 7-113), but when the fetus had trisomy 21 (n = 17) an average of 71 NRBCs were identified. Among 26 carriers of beta-thalassemia, 42 NRBCs (range 22-158) were isolated. In pregnancies with abnormal Doppler findings in both uterine arteries (n = 20), 15 NRBCs (range 2-75) were isolated.

CONCLUSION

Determining the number of NRBCs in maternal circulation could represent an additional screening step for fetal aneuploidies, as long as the anemic status of the mother is taken into consideration. However, more cases with abnormal Doppler results must be investigated before this test is used for in the prediction of pregnancy complications.

Cervical length at 22-24 weeks of gestation: comparison of transvaginal and transperineal-translabial ultrasonography

OBJECTIVES

To investigate the feasibility of measuring cervical length by transperineal or translabial sonography and compare the measurements obtained by this approach with those obtained transvaginally.

METHODS

In 500 women measurement of cervical length by translabial-transperineal sonography was attempted immediately before transvaginal scanning at 22-24 (median 23) weeks of gestation. In the first phase of the study, considered to be the learning period, 200 patients were examined and their results reviewed, before carrying out the second phase in which 300 patients were examined. A comparison was made of the patient acceptability of both techniques.

RESULTS

Cervical length was successfully measured transvaginally in all cases. In the first phase of the study cervical length was measured by translabial-transperineal sonography in 84% of the 200 patients but there was poor agreement with measurements obtained transvaginally and the 95% tolerance interval for paired observations was -11.0 mm to 16.1 mm. After audit of results it became apparent that the translabially-transperineally derived images were inadequate in more than half of the cases but in those with adequate paired measurements there was a very good agreement between the two and the 95% tolerance interval for paired observations was -5.8 mm to 5.2 mm. In the second phase of the study special attention was paid towards recording measurements of cervical length only in cases where both the internal and external os were adequately visualized. Successful measurements by translabial-transperineal sonography were obtained in 78% of cases and the 95% tolerance interval for paired observations was -5.8 mm to 6.1 mm. The degree of patient acceptability of the two methods was similar.

CONCLUSIONS

The findings of this study suggest that at 22-24 weeks of gestation the cervix can be visualized adequately by translabial-transperineal sonography in about 80% of patients and the measurements of cervical length obtained by this approach are very similar to those obtained by transvaginal sonography.

Osteogenesis imperfecta and other skeletal dysplasias presenting with increased nuchal translucency in the first trimester

We present two case reports of osteogenesis imperfecta associated with increased nuchal translucency in the first trimester. We also review the literature of first trimester diagnosis of skeletal dysplasias and their association with increased nuchal translucency.

Early prediction of severe twin-to-twin transfusion syndrome

This extended series of 303 monochorionic twin pregnancies examined at 10-14 weeks gestation explores the possible association of increased fetal nuchal translucency thickness (NT) in the early prediction of severe twin-to-twin transfusion syndrome (TTS). Of 303 pregnancies, there were 16 in which at least one fetus was structurally or chromosomally abnormal and in the remaining 287 ongoing pregnancies there were 43 (15%) which developed severe TTS. The median fetal NT was 1.0 multiples of the median (MOM) and NT was >95th centile in 47 (8.2%) fetuses and in at least one fetus in 37 (12.9%) pregnancies. The prevalence of increased NT in the pregnancies that developed TTS [17.4% (n = 15) of fetuses and 28% (n = 12) of pregnancies] was significantly higher than in the non-TTS group [6.6% (n = 32) and 10.2% (n = 25) respectively; Z: = -3.4, P: < 0.001 and Z: = 3.2, P: < 0.001 respectively], likelihood ratio of increased fetal NT for prediction of TTS = 3.5 [95% confidence interval (CI) 1.9-6.2]. In 153 of the pregnancies, an ultrasound examination was also performed at 15-17 weeks gestation and intertwin membrane folding was seen in 49 (32%) cases; 21 of these (43%) subsequently developed TTS compared to two (1.9%) of the 104 pregnancies without membrane folding (Z: = 6.6, P: < 0.001), likelihood ratio of membrane folding for prediction of TTS = 4.2 (95% CI 3.0-6.0).

First trimester diagnosis of monoamniotic twin pregnancies

This study reports the ultrasound findings and pregnancy outcome for a series of monoamniotic twin pregnancies diagnosed at 11-14 weeks' gestation. Of 315 monochorionic twin pregnancies examined, there were 12 (3.8%) monoamniotic, including four sets of conjoined twins (1.3%). The parents opted for termination of pregnancy in all cases of conjoined twins. In four other cases, there was discordancy for major structural fetal abnormality (kyphoscoliosis, anencephaly, body stalk defect, diaphragmatic hernia), and the cotwin was structurally normal. In the four cases in which both twins were structurally normal, ultrasound examination demonstrated normal nuchal translucency thickness in all cases but cord entanglement was demonstrated from the first trimester. Two cases were managed expectantly; one resulted in livebirth of both twins at 31 weeks' gestation and the second in intrauterine death of both fetuses at 21 weeks. Two pregnancies were treated with Sulindac; one resulted in a single intrauterine death at 30 weeks and delivery of a normal cotwin, the other, in intrauterine death of both fetuses at 31 weeks'. Monoamniotic twin pregnancies are associated with a high risk of fetal abnormalities and perinatal death and the mortality rate is higher than previously reported from series with recruitment later in gestation.

Increased nuchal translucency in trisomy 13 fetuses at 10-14 weeks of gestation

In a multicenter screening study for trisomy 21 involving ultrasonographic measurement of fetal nuchal translucency thickness (NT) at 10-14 weeks of gestation, 100,311 singleton pregnancies with a live fetus were examined. There were 46 cases of trisomy 13, and in 33 (72%) of these, the NT was above the 95th centile. The estimated risk for trisomy 21, based on maternal age-related risk for this chromosomal abnormality and fetal NT, was above 1 in 300 in 37 (80.1%) of the trisomy 13 fetuses. The fetal crown-rump length was significantly reduced, but the fetal heart rate was increased, being above the 95th centile in 64% of cases. Additionally, 24% of trisomy 13 fetuses had holoprosencephaly and 10% had exomphalos. This study has demonstrated that at 10-14 weeks of gestation, about 80% of fetuses with trisomy 13 can be identified in a screening program for trisomy 21, based on a combination of maternal age and fetal NT.

UK multicentre project on assessment of risk of trisomy 21 by maternal age and fetal nuchal-translucency thickness at 10-14 weeks of gestation. Fetal Medicine Foundation First Trimester Screening Group

BACKGROUND

Prenatal diagnosis of trisomy 21 currently relies on assessment of risk followed by invasive testing in the 5% of pregnancies at the highest estimated risk. Selection of the high-risk group by a combination of maternal age and second-trimester maternal serum biochemistry gives a detection rate of about 60%. We investigated assessment of risk by a combination of maternal age and fetal nuchal-translucency thickness, measured by ultrasonography at 10-14 weeks of gestation.

METHODS

The risk of trisomy 21 was estimated for 96127 women of median age 31 years (range 14-49) with singleton pregnancies. Ultrasonography was done by 306 appropriately trained sonographers in 22 centres. Risk of trisomy 21 was calculated from the maternal age and gestational-age-related prevalence, multiplied by a likelihood ratio depending on the deviation from normal in nuchal-translucency thickness for crown-rump length. The distribution of risks was investigated and the sensitivity of a cut-off risk of 1 in 300 was calculated. Phenotype was assessed by fetal karyotyping or clinical examination of liveborn infants.

FINDINGS

The estimated trisomy-21 risk, from maternal age and fetal nuchal-translucency thickness, was 1 in 300 or higher in 7907 (8.3%) of 95476 normal pregnancies, 268 (82-2%) of 326 with trisomy 21, and 253 (77.9%) of 325 with other chromosomal defects. The 5% of the study population with the highest estimated risk included 77% of trisomy-21 cases.

INTERPRETATION

Selection of the high-risk group for invasive testing by this method allows the detection of about 80% of affected pregnancies. However, even this method of risk assessment requires about 30 invasive tests for identification of one affected fetus.

Diagnosis of the Meckel-Gruber syndrome at eleven to fourteen weeks' gestation

OBJECTIVE

Our purpose was to examine the feasibility of diagnosing the Meckel-Gruber syndrome at 11 to 14 weeks' gestation, both in high-risk pregnancies and during routine ultrasonographic screening for fetal chromosomal abnormalities.

STUDY DESIGN

The high-risk population consisted of 9 pregnancies in 7 women with previous pregnancies affected by the Meckel-Gruber syndrome. At 11 to 14 weeks' gestation, systematic ultrasonographic examinations of the fetal skull, brain, kidneys, bladder, hands, and feet were undertaken in each case. The low-risk population consisted of 21,477 self-referred pregnancies undergoing first-trimester ultrasonographic screening for chromosomal defects at 11 to 14 weeks' gestation.

RESULTS

The triad of fetal occipital encephalocele, bilateral polycystic kidneys, and postaxial polydactyly was detected by transabdominal ultrasonography and confirmed by transvaginal scanning in 4 of the 9 pregnancies in the high-risk group. The parents were counseled of the likely recurrence of the Meckel-Gruber syndrome, and all elected to terminate the pregnancy by transcervical evacuation at 12 to 13 weeks. In the low-risk population the only case of Meckel-Gruber syndrome was identified at 13 weeks; in the remaining screened pregnancies there were no other cases of termination of pregnancy or neonatal death with the diagnosis of Meckel-Gruber syndrome.

CONCLUSION

This report demonstrates that the Meckel-Gruber syndrome can be confidently detected at the 11- to 14-week scan in both high- and low-risk populations.

Prevalence of fetal facial cleft at different stages of pregnancy

During a 7-year period (1988-94), we diagnosed 102 fetuses with trisomy 18, and 54 with trisomy 13; in 6.9% of the trisomy 18 and in 40.7% of the trisomy 13 fetuses, there was a facial cleft. On the basis of (1) these frequencies of facial cleft in trisomic fetuses; (2) the reported prevalence of facial cleft in mid-trimester fetuses; and (3) estimates of the prevalence of trisomies 18 and 13 at 20 weeks of gestation in a population with the maternal age distribution of all deliveries in England and Wales, it was calculated that 6.5% of fetuses with a facial cleft would have trisomy 18 or 13. This estimated frequency of trisomies was significantly lower than the 26% observed in 111 fetuses with a facial cleft that were referred to our unit for fetal karyotyping. These findings suggest that the patients with a facial cleft examined in a referral center are preselected in favor of those with multiple abnormalities, and therefore a higher frequency of associated chromosomal defects. In the future, with improving quality of ultrasound equipment and standards of scanning, it is likely that more cases of isolated facial cleft will be identified and, consequently, the observed frequency of chromosomal defects should decrease.

Fetal exomphalos and chromosomal defects: relationship to maternal age and gestation

In an ultrasound screening study involving 15,726 viable, singleton pregnancies at 11-14 weeks of gestation, exomphalos was diagnosed in 0.11% of the cases and, in those with exomphalos, the frequency of trisomy 18, trisomy 13 or triploidy was 61%. The corresponding frequencies of exomphalos of fetuses with these chromosomal defects were 22.5%, 9.1% and 12.5%, respectively. The median maternal age of the screened population was 33 (range 15-48) years, which is higher than in all pregnancies in England and Wales. Expected prevalences of trisomy 18, trisomy 13 and triploidy in the total population were derived on the basis of the age distribution of all deliveries in England and Wales and maternal and gestational age-specific risks for these chromosomal defects. From these numbers and the observed frequencies of exomphalos in association with the various chromosomal defects, it was estimated that the prevalence of exomphalos in a population with the maternal age distribution of all deliveries in England and Wales was 7.4 per 10,000 at 12 weeks of gestation, and this decreased to 3.5 at 20 weeks and 2.9 in live births. The estimated frequency of chromosomal defects in fetuses with exomphalos decreased from 39.4% at 12 weeks of gestation to 27.5% at 20 weeks and 14.4% in live births. The prevalence of chromosomal defects in 153 fetuses with exomphalos referred to our center at 16-26 (median 20) weeks of gestation was not significantly different from that predicted in an unselected population. However, the reported frequency of chromosomal defects in a total of 299 neonates with exomphalos (9.3%) was significantly lower than expected in an unselected population. This study demonstrates that the prevalence of a fetal abnormality and the frequency of associated chromosomal defects depends on the maternal age and gestational age distributions of the populations examined.

Hyperprolactinemia and impotence

One hundred impotent men and 15 sexually active male volunteers served as the source for this study. Serum prolactin was estimated in all cases using radioimmunoassay technique. Cases with hyperprolactinemia were treated with bromocriptine for 3 months. Hyperprolactinemia was detected in three patients only (3%), with no findings of pituitary tumors. Treatment with bromocriptine markedly reduced the level of serum prolactin together with improvement of sexual libido and potency. The mere presence of 3 cases only with hyperprolactinemia among 100 impotent subjects suggested that hyperprolactinemia is not one of the main causes of impotence.