A revisit of the fetal foot length and fetal measurements in early pregnancy sonography.

OBJECTIVES: To present the fetal measurements in relation to the foot length at 10-16 weeks gestation on antenatal ultrasound. MATERIALS AND METHODS: We reviewed the fetal measurements in 47 scans performed at 10-16 weeks gestation in women attending routine antenatal care. The fetal measurements and measurement ratios were examined in relation to the foot length. RESULTS: The fetal biparietal diameter, head circumference, abdominal circumference, femur length and foot length increase linearly with the gestational age at 10-16 weeks gestation. The correlation between fetal foot length and fetal biparietal diameter, head circumference, abdominal circumference and femur length are better than with the crown rump length. The femur length to foot length ratio and the femur length to abdominal circumference ratios increase with the gestational age in an inverse relationship throughout the same period. CONCLUSION: Fetal foot length is an accurate estimate of the gestational age in early pregnancy. Compared with crown rump length, the correlation between foot length and other fetal measurements is better. The fetal measurements ratios are gestational age dependent between 10-16 weeks. Gestational age specific ratio should be used in this period.

Pregnancy complicated by morbidly adherent placenta in a patient with bilateral ovarian agenesis: a case report.

The author presents a case of in vitro fertilization pregnancy complicated by morbidly adherent placenta in a patient with congenital bilateral ovarian agenesis. A 31-year-old woman with congenital bilateral ovarian agenesis who had undergone two previous dilatation and curettage procedures conceived following in vitro fertilization with a donor egg. Spontaneous labor occurred at 38 weeks and 5 days' gestation. The labor was augmented in the active phase and resulted in instrumental vaginal delivery. The third stage was complicated by hemorrhage and retained placenta. Morbidly adherent placenta was diagnosed on attempt at manual removal of the placenta, and the adherent part of the placenta was left in situ. This was removed uneventfully at 5 weeks following childbirth when there was no blood flow observed between the placenta and the myometrium on Doppler ultrasound examination. In conclusion, successful parturition is possible in patients with congenital bilateral ovarian agenesis. When morbidly adherent placenta is managed conservatively, the placenta may be safely removed if there is no vascularity between the placenta and the myometrium.

Placenta accreta in the first trimester of pregnancy: sonographic findings.

In a case of histologically confirmed placenta increta, decidual protrusion into the myometrium was observed sonographically at 6 weeks' gestation, corresponding to placental protrusion from a disrupted placental-uterine wall interface seen in the later part of the first and second trimester. It is hypothesized that the histologic finding of decidual scarcity in placenta accreta is not a cause but rather an end result of the recruitment of trophoblasts across the decidual-placental interface in a maternal attempt at healing and/or repair in the presence of uterine injury, disease, or malformation that accounts for the associated factors and course of the condition.

Antenatal topographical assessment of placenta accreta with ultrasound.

The major risk of placenta accreta is severe haemorrhage when the placenta is separated at delivery. A case series of placenta accreta with antenatal sonographic topographical assessment of myometrial involvement is presented. The extent of myometrial involvement and the vascularity could be assessed by the observation of the extent of placental-uterine wall interface disruption and the vessels crossing the interface disruption sites. Such assessment results in strategic planning of management of the placenta at delivery with favourable pregnancy outcomes.

Evaluation of sonographic diagnostic criteria for placenta accreta.

PURPOSE: To compare the diagnostic value of reported sonographic criteria for placenta accreta and to develop a composite score system for antenatal evaluation. METHOD: Sixty-six women at risk for placenta accreta were examined for 9 cases of placenta accreta that were confirmed at delivery. The performance of previously reported gray-scale and Doppler sonographic criteria for the diagnosis of placenta accreta was analyzed individually. A composite score system was developed by combining selected sensitive or specific sonographic criteria, and its performance was evaluated. RESULTS: The criteria of obliteration of retroplacental clear space, a myometrial thickness of <1 mm, presence of vessels bridging placenta and uterine margin, disruption of the placental-uterine wall interface, and vessels crossing the sites of interface disruption showed a statistically significant association with placenta accreta. The disruption of the placental-uterine wall interface and the presence of vessels crossing these sites were the only 2 individual criteria that could distinguish placenta accreta from non-accreta, which could also be achieved by our composite score system using a cutoff value of 40, with a sensitivity of 89% and specificity of 98%. CONCLUSION: The diagnostic performance of the sonographic diagnostic criteria used in the diagnosis of placenta accreta varies, and a composite score system improves the overall accuracy.

The maternal outcome in placenta accreta: the significance of antenatal diagnosis and non-separation of placenta at delivery.

AIM: To evaluate the effects of antenatal diagnosis and subsequent placental non-separation at delivery on the maternal outcome in confirmed cases of placenta accreta. METHOD: The perinatal database and medical records for women who delivered in the period 2000-6 in a teaching hospital in New Zealand with a diagnosis of placenta accreta or postpartum haemorrhage or hysterectomy were reviewed. In confirmed placenta accreta cases, the amount of blood loss and blood transfused at delivery and subsequent emergency hysterectomy were analysed in respect to the presence/absence of antenatal diagnosis and the management at delivery. RESULTS: 16 women had placenta accreta confirmed (15 histologically and 1 visually). Antenatal diagnosis was made in 7 women, elective Caesarean delivery planned in all, hysterectomy to follow in 5 (4 elective, 1 emergency preterm), and elective placental separation in 2 women. When an antenatal diagnosis was not made (n=9), attempted placental separation led to emergency hysterectomy for all (p=0.001). Antenatal diagnosis and placental non-separation resulted in less mean blood loss (1.4 L vs 3.6 L, p=0.003; 1.0 L vs 3.4 L, p<0.001) and mean units of blood transfused (1.2 vs 5.1, p=0.005) in the latter. CONCLUSION: In placenta accreta, antenatal diagnosis and avoidance of placental separation may result in better maternal outcome.

Comparison and integration of first trimester fetal nuchal translucency and second trimester maternal serum screening for fetal Down syndrome.

BACKGROUND: It is uncertain whether first trimester nuchal translucency (NT) is more effective than the well-established second trimester serum screening for fetal Down syndrome or whether their combination works best. We report data from a large multicentre non-interventional trial in which all subjects underwent both first and second trimester screening. METHODS: All women who attended the obstetric clinic before 15 weeks' gestation were recruited. An ultrasound examination was performed at 10 to 14 weeks to measure the NT. The nuchal measurements were not acted upon unless the fetus showed gross features of hydrops fetalis. All women had serum alpha-fetoprotein (AFP) and human chorionic gonadotrophin (hCG) assay at 15 to 20 weeks. The Down syndrome risk assigned by serum screening was disclosed and amniocentesis was offered if this assigned risk was >or=1:250 or if the women were 35 years and older. The efficacy of different combinations of screening markers was compared. RESULTS: Between January 1997 and August 2000, 17 590 women were recruited (19% >or=35 years old). After excluding subjects who miscarried, defaulted the serum test and other reasons, 16 237 pregnancies were analysed. Of these, 35 pregnancies were affected by Down syndrome (2.2 cases per 1000 pregnancies). At a false-positive rate of 5%, the detection rate of Down syndrome by NT alone, NT and age, serum hCG, AFP and age, and NT, hCG, AFP and age were 61%, 69%, 73% and 86%, respectively. CONCLUSION: Integration of NT and second trimester serum AFP and hCG assay yielded the best screening efficacy for Down syndrome.

The effect of ethnic origin on nuchal translucency at 10-14 weeks of gestation.

INTRODUCTION: Fetal nuchal translucency (NT) increases with gestation and is affected by fetal posture and fetal gender. A recent report suggested that there might also be ethnic differences. We investigated the effect of ethnic origin on NT in an Asian population. METHODS: NT was measured at 10-14 weeks. The measurements were converted into multiples of the median (MoM) for gestational day. The risk of Down syndrome was calculated by combining NT and maternal age. Cases affected by chromosomal and major structural abnormalities were excluded. NT measurements of different ethnic groups were compared. RESULTS: Between January 1997 and October 2001, 16 981 pregnancies with known ethnic origin and normal fetal outcome were analysed. Median NT MoM (95% CI) of the Filipinos was 1.07 (1.04-1.11). This was significantly higher than that of the Chinese, 1.01 (1.01-1.02); other Asians (Indians, Pakistanis and Nepalese), 0.96 (0.94-0.99), and Caucasians, 0.98 (0.93-1.06) (p<0.05, respectively; Mann-Whitney U-test). An NT risk cut-off of 1:180 would classify 5% of the Chinese, 4.6% of the Caucasians, 5.6% of the Filipinos and 4.2% of the other Asians as screen-positive. There were no statistically significant differences between these screen-positive rates (p>0.05, Chi-square test). CONCLUSIONS: Although there were statistically significant differences in NT measurements between different ethnic groups, it was clinically insignificant, as reflected by similar screen-positive rates.