International estimated fetal weight standards of the INTERGROWTH-21st Project

OBJECTIVE

Estimated fetal weight (EFW) and fetal biometry are complementary measures used to screen for fetal growth disturbances. Our aim was to provide international EFW standards to complement the INTERGROWTH-21^st Fetal Growth Standards that are available for use worldwide.

METHODS

Women with an accurate gestational-age assessment, who were enrolled in the prospective, international, multicenter, population-based Fetal Growth Longitudinal Study (FGLS) and INTERBIO-21^st Fetal Study (FS), two components of the INTERGROWTH-21^st Project, had ultrasound scans every 5 weeks from 9-14 weeks' until 40 weeks' gestation. At each visit, measurements of fetal head circumference (HC), biparietal diameter, occipitofrontal diameter, abdominal circumference (AC) and femur length (FL) were obtained blindly by dedicated research sonographers using standardized methods and identical ultrasound machines. Birth weight was measured within 12 h of delivery by dedicated research anthropometrists using standardized methods and identical electronic scales. Live babies without any congenital abnormality, who were born within 14 days of the last ultrasound scan, were selected for inclusion. As most births occurred at around 40 weeks' gestation, we constructed a bootstrap model selection and estimation procedure based on resampling of the complete dataset under an approximately uniform distribution of birth weight, thus enriching the sample size at extremes of fetal sizes, to achieve consistent estimates across the full range of fetal weight. We constructed reference centiles using second-degree fractional polynomial models.

RESULTS

Of the overall population, 2404 babies were born within 14 days of the last ultrasound scan. Mean time between the last scan and birth was 7.7 (range, 0-14) days and was uniformly distributed. Birth weight was best estimated as a function of AC and HC (without FL) as log(EFW) = 5.084820 - 54.06633 × (AC/100)³  - 95.80076 × (AC/100)³  × log(AC/100) + 3.136370 × (HC/100), where EFW is in g and AC and HC are in cm. All other measures, gestational age, symphysis-fundus height, amniotic fluid indices and interactions between biometric measures and gestational age, were not retained in the selection process because they did not improve the prediction of EFW. Applying the formula to FGLS biometric data (n = 4231) enabled gestational age-specific EFW tables to be constructed. At term, the EFW centiles matched those of the INTERGROWTH-21^st Newborn Size Standards but, at < 37 weeks' gestation, the EFW centiles were, as expected, higher than those of babies born preterm. Comparing EFW cross-sectional values with the INTERGROWTH-21^st Preterm Postnatal Growth Standards confirmed that preterm postnatal growth is a different biological process from intrauterine growth.

CONCLUSIONS

We provide an assessment of EFW, as an adjunct to routine ultrasound biometry, from 22 to 40 weeks' gestation. However, we strongly encourage clinicians to evaluate fetal growth using separate biometric measures such as HC and AC, as well as EFW, to avoid the minimalist approach of focusing on a single value. © 2016 Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

First-trimester maternal serum activin A in pre-eclampsia and fetal growth restriction

OBJECTIVE

To investigate whether the reported increase in maternal serum activin A concentration in pre-eclampsia is evident from the first trimester.

DESIGN

This was a case-control study carried out in antenatal clinics among singleton pregnancies at 10-14 weeks of gestation.

METHODS

Activin A concentration was measured in stored maternal serum samples obtained at 11-14 weeks of gestation from 131 women who subsequently developed pre-eclampsia, 77 who developed non-proteinuric pregnancy-induced hypertension, 141 with fetal growth restriction in the absence of hypertensive complications and from 494 normotensive controls.

RESULTS

Compared to the median activin A level in the control group (1.00 MoM), the median MoM in the patients who subsequently developed pre-eclampsia and pregnancy-induced hypertension (1.49 MoM and 1.32 MoM, respectively) was significantly increased (p < 0.001), and in patients with fetal growth restriction (1.02 MoM) it was not significantly different (p = 0.57). In the pre-eclampsia group (n = 131) the disease was considered to be sufficiently severe to necessitate iatrogenic delivery before 35 weeks in 25 patients, and in this group the median MoM was 1.92.

CONCLUSION

Maternal serum activin A concentration at 12 weeks of gestation in pregnancies which subsequently develop hypertensive disease is increased, whereas in those complicated by fetal growth restriction it is normal.

Knowledge and awareness of pregnant women about ultrasounsd scanning and prenatal diagnosis

OBJECTIVE

Antenatal screening and ultrasound scan has become an integral part of the antenatal care in the present time. The aim of this study is to accurately describe the background knowledge and awareness of pregnant women about ultrasound scan and prenatal diagnosis.

METHODS

It is a clinic based cross sectional study. Four hundred women, attending the antenatal clinics, were asked to fill in a pre tested structured questionnaire. Different variables of interest were collected. Statistical Program for the social sciences (SPSS) was used for the data management.

RESULTS

Over 93.5% of the women were aware that ultrasound examination is an important investigation. They believed that it should be performed at least twice during pregnancy but were not sure about the timing of the test. Most of them felt that it was to check the growth of the baby and 97% of women considered ultrasound to be safe. However, only 26% of women had any knowledge about Down's syndrome or its screening.

CONCLUSION

Pregnant women in our set-up are aware of importance of ultrasound examination during pregnancy. However, there is a need to improve public awareness of problems like Down's syndrome.

Effectiveness of early pregnancy ultrasound in diagnosing fetal abnormalities in high risk women

OBJECTIVE

To assess the efficacy of 11-14 weeks ultrasound in the diagnosis of fetal abnormalities in high risk women.

METHODS

Prospective study conducted at a teaching hospital in Karachi, Pakistan. One hundred ultrasound (mini-anomaly) scans were performed on 97 high-risk women, between 11-14 weeks of gestation.

RESULTS

The most common indication for the ultrasound scan in the study, was previous history of structural or chromosomal abnormalities (40%) followed by advanced maternal age (22%). Out of 100 ultrasounds performed, two were found to have structural abnormalities at the time of mini-anomaly scan performed at 11-14 weeks. None of the ultrasound scans found to be normal at 11-14 weeks showed an abnormality on the subsequent scans.

CONCLUSION

Ultrasound scan performed between 11-14 weeks of pregnancy is effective in diagnosing major fetal abnormalities in the high-risk population. It can complement the anomaly scan performed in the second trimester, as some of the abnormalities become evident later in pregnancy.

First trimester maternal serum free beta human chorionic gonadotrophin and pregnancy associated plasma protein A as predictors of pregnancy complications

OBJECTIVE

To examine the value of first trimester maternal serum free beta human chorionic gonadotrophin (beta hCG) and pregnancy associated plasma protein A (PAPP-A) as predictors of pregnancy complications.

DESIGN

Screening study.

SETTING

Antenatal clinics.

POPULATION

Singleton pregnancies at 10-14 weeks of gestation.

METHODS

Maternal serum free beta hCG and PAPP-A were measured at 10-14 weeks of gestation in 5,584 singleton pregnancies. In the 5,297 (94.9%) pregnancies with complete follow up free beta hCG and PAPP-A were compared between those with normal outcome and those resulting in miscarriage, spontaneous preterm delivery, pregnancy induced hypertension or fetal growth restriction and in those with pre-existing or gestational diabetes.

RESULTS

Maternal serum PAPP-A increased and beta hCG decreased with gestation. The multiple of median maternal serum PAPP-A was significantly lower in those pregnancies resulting in miscarriage, pregnancy induced hypertension, growth restriction and in those with pre-existing or gestational diabetes mellitus, but not in those complicated by spontaneous preterm delivery. The level was < 10th centile of the reference range in about 20% of the pregnancies that subsequently resulted in miscarriage or developed pregnancy induced hypertension or growth restriction, and in 27% of those that developed gestational diabetes. Maternal serum free beta hCG was < 10th centile of the reference range in about 15% of the pregnancies that subsequently resulted in miscarriage or developed pregnancy induced hypertension or growth restriction, and in 20% of those that developed gestational diabetes.

CONCLUSION

Low maternal serum PAPP-A or beta hCG at 10-14 weeks of gestation are associated with subsequent development of pregnancy complications.

The effect of grandmultiparity on pregnancy related complications: the Aga Khan University experience

BACKGROUND

Grandmultiparity has been associated with complications for both mother and the fetus.

OBJECTIVE

To evaluate if grandmultiparity is a risk factor in the presence of adequate antenatal care.

SETTING

A tertiary care teaching hospital.

METHODS

It was a retrospective study conducted in the department of Obstetrics & Gynecology at The Aga Khan University Hospital in Karachi. During this period 9253 women were delivered, out of these 143 booked grandmultiparas (GMP) served as cases. The outcome of these women was compared with 430 non-grandmultiparas (NGMP). Logistic regression model was used to adjust for potential confounders.

RESULTS

Grandmultiparas had almost three times increased risk of having postpartum hemorrhage compared to NGMP group. Similarly, there were significantly low five-minute apgars in the GMPs compared to the NGMP group. Although the neonatal intensive care admissions were three times more in the GMPs but this did not reach statistical significance due to small number of cases in both groups.

CONCLUSION

Our study indicates that grandmultiparity is a risk factor for pregnancy in this part of the world, even in the presence of reasonable antenatal care. This may be explained on the basis of the increased age of these women. Finally, we also recommend that an age-matched study needs to be undertaken in order to determine if age is an important determinant for risk factors in grandmultiparas.

Outcome of abruptio placentae in normotensive and hypertensive patients in Aga Khan University Hospital, Pakistan

The aim of our study was to compare the perinatal and maternal outcome in hypertensive women experiencing abruptio placentae with that of normotensive women. We hypothesized that hypertensive women experiencing abruptio had a less favorable outcome than the normotensive women. Ours was a retrospective cohort study, in which the outcome of 33 hypertensive women with abruptio was compared with 138 normotensive women experiencing abruptio placentae. Our results indicate that although higher number of hypertensive women with abruptio had a past history of hypertension and were more likely to have diabetes (p = 0.05) there was no difference found in the grades of abruption or in any other antenatal complications between the 2 groups. The hypertensive women were also more likely to undergo cesarean section. We did not find any difference in the neonatal outcome. Therefore, we conclude that there is no difference in the maternal and perinatal outcome between the hypertensive and normotensive women experiencing abruptio.