Customised fetal growth assessment

Indicated vs universal third-trimester ultrasound examination in low-risk pregnancies: a pre-post-intervention study

BACKGROUND

In low-risk pregnancies, a third-trimester ultrasound examination is indicated if fundal height measurement and gestational age discrepancy are observed. Despite potential improvement in the detection of ultrasound abnormality, prior trials to date on universal third-trimester ultrasound examination in low-risk pregnancies, compared with indicated ultrasound examination, have not demonstrated improvement in neonatal or maternal adverse outcomes.

OBJECTIVE

The primary objective was to determine if universal third-trimester ultrasound examination in low-risk pregnancies could attenuate composite neonatal adverse outcomes. The secondary objectives were to compare changes in composite maternal adverse outcomes and detection of abnormalities of fetal growth (fetal growth restriction or large for gestational age) or amniotic fluid (oligohydramnios or polyhydramnios).

STUDY DESIGN

Our pre-post intervention study at 9 locations included low-risk pregnancies, those without indication for ultrasound examination in the third trimester. Compared with indicated ultrasound in the preimplementation period, in the postimplementation period, all patients were scheduled for ultrasound examination at 36.0-37.6 weeks. In both periods, clinicians intervened on the basis of abnormalities identified. Composite neonatal adverse outcomes included any of: Apgar score ≤5 at 5 minutes, cord pH <7.00, birth trauma (bone fracture or brachial plexus palsy), intubation for >24 hours, hypoxic-ischemic encephalopathy, seizure, sepsis (bacteremia proven with blood culture), meconium aspiration syndrome, intraventricular hemorrhage grade III or IV, periventricular leukomalacia, necrotizing enterocolitis, stillbirth after 36 weeks, or neonatal death within 28 days of birth. Composite maternal adverse outcomes included any of the following: chorioamnionitis, wound infection, estimated blood loss >1000 mL, blood transfusion, deep venous thrombus or pulmonary embolism, admission to intensive care unit, or death. Using Bayesian statistics, we calculated a sample size of 600 individuals in each arm to detect >75% probability of any reduction in primary outcome (80% power; 50% hypothesized risk reduction).

RESULTS

During the preintervention phase, 747 individuals were identified during the initial ultrasound examination, and among them, 568 (76.0%) met the inclusion criteria at 36.0-37.6 weeks; during the postintervention period, the corresponding numbers were 770 and 661 (85.8%). The rate of identified abnormalities of fetal growth or amniotic fluid increased from between the pre-post intervention period (7.1% vs 22.2%; P<.0001; number needed to diagnose, 7; 95% confidence interval, 5-9). The primary outcome occurred in 15 of 568 (2.6%) individuals in the preintervention and 12 of 661 (1.8%) in the postintervention group (83% probability of risk reduction; posterior relative risk, 0.69 [95% credible interval, 0.34-1.42]). The composite maternal adverse outcomes occurred in 8.6% in the preintervention and 6.5% in the postintervention group (90% probability of risk; posterior relative risk, 0.74 [95% credible interval, 0.49-1.15]). The number needed to treat to reduce composite neonatal adverse outcomes was 121 (95% confidence interval, 40-200). In addition, the number to reduce composite maternal adverse outcomes was 46 (95% confidence interval, 19-74), whereas the number to prevent cesarean delivery was 18 (95% confidence interval, 9-31).

CONCLUSION

Among low-risk pregnancies, compared with routine care with indicated ultrasound examination, implementation of a universal third-trimester ultrasound examination at 36.0-37.6 weeks attenuated composite neonatal and maternal adverse outcomes.

Fetal Growth Restriction: ACOG Practice Bulletin, Number 227

Fetal growth restriction, also known as intrauterine growth restriction, is a common complication of pregnancy that has been associated with a variety of adverse perinatal outcomes. There is a lack of consensus regarding terminology, etiology, and diagnostic criteria for fetal growth restriction, with uncertainty surrounding the optimal management and timing of delivery for the growth-restricted fetus. An additional challenge is the difficulty in differentiating between the fetus that is constitutionally small and fulfilling its growth potential and the small fetus that is not fulfilling its growth potential because of an underlying pathologic condition. The purpose of this document is to review the topic of fetal growth restriction with a focus on terminology, etiology, diagnostic and surveillance tools, and guidance for management and timing of delivery.

Routine ultrasound in late pregnancy (after 24 weeks' gestation)

BACKGROUND

Diagnostic ultrasound is used selectively in late pregnancy where there are specific clinical indications. However, the value of routine late pregnancy ultrasound screening in unselected populations is controversial. The rationale for such screening would be the detection of clinical conditions which place the fetus or mother at high risk, which would not necessarily have been detected by other means such as clinical examination, and for which subsequent management would improve perinatal outcome.

OBJECTIVES

To assess the effects on obstetric practice and pregnancy outcome of routine late pregnancy ultrasound, defined as greater than 24 weeks' gestation, in women with either unselected or low-risk pregnancies.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 May 2015) and reference lists of retrieved studies.

SELECTION CRITERIA

All acceptably controlled trials of routine ultrasound in late pregnancy (defined as after 24 weeks).

DATA COLLECTION AND ANALYSIS

Three review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy.

MAIN RESULTS

Thirteen trials recruiting 34,980 women were included in the systematic review. Risk of bias was low for allocation concealment and selective reporting, unclear for random sequence generation and incomplete outcome data and high for blinding of both outcome assessment and participants and personnel. There was no difference in antenatal, obstetric and neonatal outcome or morbidity in screened versus control groups. Routine late pregnancy ultrasound was not associated with improvements in overall perinatal mortality. There is little information on long-term substantive outcomes such as neurodevelopment. There is a lack of data on maternal psychological effects.Overall, the evidence for the primary outcomes of perinatal mortality, preterm birth less than 37 weeks, induction of labour and caesarean section were assessed to be of moderate or high quality with GRADE software. There was no association between ultrasound in late pregnancy and perinatal mortality (risk ratio (RR) 1.01, 95% confidence interval (CI) 0.67 to 1.54; participants = 30,675; studies = eight; I² = 29%), preterm birth less than 37 weeks (RR 0.96, 95% CI 0.85 to 1.08; participants = 17,151; studies = two; I² = 0%), induction of labour (RR 0.93, 95% CI 0.81 to 1.07; participants = 22,663; studies = six; I² = 78%), or caesarean section (RR 1.03, 95% CI 0.92 to 1.15; participants = 27,461; studies = six; I² = 54%). Three additional primary outcomes chosen for the 'Summary of findings' table were preterm birth less than 34 weeks, maternal psychological effects and neurodevelopment at age two. Because none of the included studies reported these outcomes, they were not assessed for quality with GRADE software.

AUTHORS' CONCLUSIONS

Based on existing evidence, routine late pregnancy ultrasound in low-risk or unselected populations does not confer benefit on mother or baby. There was no difference in the primary outcomes of perinatal mortality, preterm birth less than 37 weeks, caesarean section rates, and induction of labour rates if ultrasound in late pregnancy was performed routinely versus not performed routinely. Meanwhile, data were lacking for the other primary outcomes: preterm birth less than 34 weeks, maternal psychological effects, and neurodevelopment at age two, reflecting a paucity of research covering these outcomes. These outcomes may warrant future research.

Routine ultrasound in late pregnancy (after 24 weeks' gestation)

BACKGROUND

Diagnostic ultrasound is used selectively in late pregnancy where there are specific clinical indications. However, the value of routine late pregnancy ultrasound screening in unselected populations is controversial. The rationale for such screening would be the detection of clinical conditions which place the fetus or mother at high risk, which would not necessarily have been detected by other means such as clinical examination, and for which subsequent management would improve perinatal outcome.

OBJECTIVES

To assess the effects on obstetric practice and pregnancy outcome of routine late pregnancy ultrasound, defined as greater than 24 weeks' gestation, in women with either unselected or low-risk pregnancies.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (February 2008).

SELECTION CRITERIA

All acceptably controlled trials of routine ultrasound in late pregnancy (defined as after 24 weeks).

DATA COLLECTION AND ANALYSIS

All three review authors were involved in assessing trial quality and data extraction.

MAIN RESULTS

Eight trials recruiting 27,024 women were included. The quality of trials overall was satisfactory. There was no difference in antenatal, obstetric and neonatal intervention or morbidity in screened versus control groups. There was a slightly higher caesarean section rate in the screened group, but this difference did not reach statistical significance. Routine late pregnancy ultrasound was not associated with improvements in overall perinatal mortality. Placental grading as an adjunct to third trimester examination scan was associated with a significant reduction in the stillbirth rate in the one trial that assessed it. There is little information on long-term substantive outcomes such as neurodevelopment. There is a lack of data on maternal psychological effects.

AUTHORS' CONCLUSIONS

Based on existing evidence, routine late pregnancy ultrasound in low-risk or unselected populations does not confer benefit on mother or baby. It may be associated with a small increase in caesarean section rates. There is a lack of data about the potential psychological effects of routine ultrasound in late pregnancy, and limited data about its effects on both short- and long-term neonatal and childhood outcome. Placental grading in the third trimester may be valuable, but whether reported results are reproducible remains to be seen, and future research of late pregnancy ultrasound should include evaluation of placental textural assessment.

Revising the primigravid partogram: does it make any difference?

OBJECTIVE

To investigate the distribution of the rate of cervical dilatation of primigravid labour and its deviation from the standard partogram.

DESIGN

Retrospective observational study.

SETTING

South African district hospital serving an indigent rural population.

POPULATION

Expectant management of labour of healthy nulliparous women in active labour, at term, with a singleton pregnancy and cephalic presentation.

METHODS

Audit of 1,595 partograms of spontaneous primigravid labour. The standard partogram's alert line was replaced by a customised alert line based on the lowest 10th centile of the rate of cervical dilatation of the study population and an alert line representing the 10% slowest labours. The action line was placed parallel and 4 h to the right of the alert lines.

MAIN OUTCOME MEASURE

The distribution of labours left to and on the respective alert lines, and right to the action lines.

RESULTS

The lowest 90th centile of the customised alert line yielded a rate of cervical dilatation of 0.860 cm/h. Three quarters of labours evolved left to the revised alert line as opposed to 56.1% left of the standard alert line [Odds ratio (OR) 0.49, 95% confidence interval (CI) 0.42-0.56]. The mean rate of cervical dilatation of the 10% slowest labours was 0.535 +/- 0.076 cm/h (P < 0.0001), and 95.7% of labours evolved left to the corresponding alert line (OR 8.40, 95% CI 6.44-11.0).

CONCLUSION

The alert line representing the mean of the 10% slowest labours leads to an unrealistic distribution of labour on the partogram. A revised alert line based on the lowest 10th centile of the local population is more representative and should perhaps be used in the management of labour.

WITHDRAWN: Routine ultrasound in late pregnancy (after 24 weeks' gestation)

BACKGROUND

Diagnostic ultrasound is used selectively in late pregnancy where there are specific clinical indications. However, the value of routine late pregnancy ultrasound screening in unselected populations is controversial. The rationale for such screening would be the detection of clinical conditions which place the fetus or mother at high risk, which would not necessarily have been detected by other means such as clinical examination, and for which subsequent management would improve perinatal outcome.

OBJECTIVES

To assess the effects on obstetric practice and pregnancy outcome of routine late pregnancy ultrasound, defined as greater than 24 weeks gestation, in women with either unselected or low risk pregnancies.

SEARCH STRATEGY

The Cochrane Pregnancy and Childbirth Group Specialised Register of Controlled Trials and the Cochrane Controlled Trials Register were searched.

SELECTION CRITERIA

All acceptably controlled trials of routine ultrasound in late pregnancy (defined as after 24 weeks).

DATA COLLECTION AND ANALYSIS

The principal reviewer assessed trial quality and extracted data, under supervision of the co-reviewer.

MAIN RESULTS

Seven trials recruiting 25,036 women were included. The quality of trials overall was satisfactory. There was no difference in antenatal, obstetric and neonatal intervention or morbidity in screened versus control groups. Routine late pregnancy ultrasound was not associated with improvements in overall perinatal mortality. Placental grading as an adjunct to third trimester examination scan was associated with a significant reduction in the stillbirth rate in the one trial that assessed it. There is a lack of data with regard to long term substantive outcomes such as neurodevelopment. There is a lack of data on maternal psychological effects.

AUTHORS' CONCLUSIONS

Based on existing evidence, routine late pregnancy ultrasound in low risk or unselected populations does not confer benefit on mother or baby. There is a lack of data about the potential psychological effects of routine ultrasound in late pregnancy, and the effects on both short and long term neonatal and childhood outcome. Placental grading in the third trimester may be valuable, but whether reported results are reproducible remains to be seen, and future research of late pregnancy ultrasound should include evaluation of placental textural assessment.

Endocrine profile of children with intrauterine growth retardation

BACKGROUND

Intrauterine growth retardation (IUGR) is a major cause of short stature in childhood. Most but not all children experience catch-up growth by 2 years of age.

METHODS

We investigated the endocrine profile (thyroid function, prolactin, cortisol, C-peptide and insulin-like growth factor-I [IGF-IJ levels) of 57 children with IUGR, aged 2-10 years, and compared it with 30 controls whose birth weight was appropriate-for-gestational-age.

RESULTS

The hormonal profile for both groups was similar for thyroid hormones, prolactin, C-peptide and IGF-I. Cortisol levels were significantly lower in the IUGR group compared to controls (p <0,05). When the IUGR group was divided into 'catch-up' growth and 'non-catch-up' subgroups, the latter had significantly lower IGF-I levels (p <0.001).

CONCLUSIONS

Lower cortisol levels in children born with IUGR may reflect impaired function of the hypothalamic-pituitary-adrenal axis associated with this condition. The significantly lower IGF-I levels of the 'non-catch-up' subgroup may be involved in their failure to grow.

The effect of intrauterine growth restriction on the development and health of children

The neurodevelopmental and cognitive outcome of long-term Intrauterine Growth Restriction (IUGR) has been followed up from pregnancy to school age at the Tel Aviv Child Development Centre.

Six-year follow-up of children with intrauterine growth retardation: long-term, prospective study

This prospective study was designed to characterize the neurodevelopmental and cognitive difficulties specific to children with intrauterine growth retardation and to detect early clinical predictors of these difficulties. Eighty-one children with intrauterine growth retardation were monitored up to 6 to 7 years of age using biometric parameters, perinatal risk questionnaires, and detailed neurodevelopmental and cognitive assessments. Forty-one children served as age-matched, appropriate for gestational age controls. A significant difference in growth parameters (P < .001), neurodevelopmental score (P < .05), and IQ (P < .05) was found between the children with intrauterine growth retardation and controls. A specific profile of difficulties in coordination, lateralization, spatial and graphomotor skills, and abundance of associated movements is typical of the children with intrauterine growth retardation and hints at possible later learning disabilities. The clinical parameters best predicting neurodevelopmental outcome were the neonatal risk score (P < .05) and the weight and height at 6 years of age (P < .05). The children with intrauterine growth retardation with neonatal complications had lower neurodevelopmental scores than the controls but no difference in IQ. Intrauterine growth retardation children diagnosed prenatally had the same neurodevelopmental and IQ scores as those diagnosed at birth, probably due to the careful perinatal and obstetric care provided. Children with intrauterine growth retardation demonstrate a specific profile of neurodevelopmental disabilities at preschool age. Early diagnosis and intervention could probably reduce these difficulties to a minimum.

Fetal growth charts for Aboriginal fetuses

The study aimed to determine whether fetal growth parameters in Aboriginal pregnancies are such that separate fetal growth charts are necessary for their appropriate care. We designed a prospective study of a cohort of Aboriginal women presenting for antenatal care before 20 weeks gestation (ultrasound proven) and a reference cohort of Caucasian women. Four remote North Queensland communities served by the Far North Regional Obstetric and Gynaecological Service (FROGS) and the antenatal clinic at Cairns Base Hospital took part in the survey One hundred and four Aboriginal and 101 Caucasian women with no known medical factors affecting fetal growth or gestation were recruited, and 96 Aboriginal and 96 Caucasian women completed the study Measurements took the form of longitudinal percentile charts of fetal biparietal diameter, abdominal circumference and femur length. Ultrasound measurements of fetal biparietal diameter, abdominal circumference and femur length were obtained 3 to 5 times during Aboriginal and Caucasian pregnancies, where the gestation was established by ultrasound before 20 weeks gestation, and no known medical conditions which affect fetal growth were present in the mother. There were no statistical or clinically important differences in biparietal diameter, femur length and abdominal circumference of Aboriginal and Caucasian fetuses. We concluded that there is no reason to use separate fetal growth charts when examining Aboriginal fetal growth.

Customised gravidogram and fetal growth chart in a South African population

OBJECTIVE

To investigate whether gravidograms and fetal growth curves should be customized, i.e. tailor made for a specific ethnic group.

METHODS

A cross-sectional study of 800 pregnant Xhosa women attending antenatal care in the Eastern Cape Province (South Africa). The data measured was used to compare the correlation between the symphysis-fundus height measurement (SFHM) and the sonographic estimate of gestational age (SEGA), as well as the intra-uterine fetal growth curve with existing gravidograms and fetal growth charts.

RESULTS

There was a good correlation between the SFHM and the SEGA: r = 0.91 (P < 0.0001). The correlation between the SFHM and the sonographic estimate of fetal weight (SEFW) yielded a correlation coefficient (r) of 0.40 (P < 0.0001). The correlation between the SEFW and SEGA resulted in a r = 0.97 (P < 0.0001). The customized gravidogram and fetal growth chart followed the general trend seen in their Caucasian equivalents.

CONCLUSION

The comparison of our customized gravidogram and intra-uterine fetal growth curve with similar charts established in Caucasians does not show any significant difference.