Estimation of gestational age from fundal height: a solution for resource-poor settings

Many women in resource-poor settings lack access to reliable gestational age assessment because they do not know their last menstrual period; there is no ultrasound (US) and methods of newborn gestational age dating are not practised by birth attendants. A bespoke multiple-measures model was developed to predict the expected date of delivery determined by US. The results are compared with both a linear and a nonlinear model. Prospectively collected early US and serial symphysis-pubis fundal height (SFH) data were used in the models. The data were collected from Karen and Burmese women attending antenatal care on the Thai–Burmese border. The multiple-measures model performed best, resulting in a range of accuracy depending on the number of SFH measures recorded per mother (for example six SFH measurements resulted in a prediction accuracy of ±2 weeks). SFH remains the proxy for gestational age in much of the resource-poor world. While more accurate measures should be encouraged, we demonstrate that a formula that incorporates at least three SFH measures from an individual mother and the slopes between them provide a significant increase in the accuracy of prediction compared with the linear and nonlinear formulae also using multiple SFH measures

Ultrasound Evidence of Early Fetal Growth Restriction after Maternal Malaria Infection

BACKGROUND: Intermittent preventive treatment (IPT), the main strategy to prevent malaria and reduce anaemia and low birthweight, focuses on the second half of pregnancy. However, intrauterine growth restriction may occur earlier in pregnancy. The aim of this study was to measure the effects of malaria in the first half of pregnancy by comparing the fetal biparietal diameter (BPD) of infected and uninfected women whose pregnancies had been accurately dated by crown rump length (CRL) before 14 weeks of gestation. METHODOLOGY/PRINCIPAL FINDINGS: In 3,779 women living on the Thai-Myanmar border who delivered a normal singleton live born baby between 2001-10 and who had gestational age estimated by CRL measurement <14 weeks, the observed and expected BPD z-scores (<24 weeks) in pregnancies that were (n = 336) and were not (n = 3,443) complicated by malaria between the two scans were compared. The mean (standard deviation) fetal BPD z-scores in women with Plasmodium (P) falciparum and/or P.vivax malaria infections were significantly lower than in non-infected pregnancies; -0.57 (1.13) versus -0.10 (1.17), p<0.001. Even a single or an asymptomatic malaria episode resulted in a significantly lower z-score. Fetal female sex (p<0.001) and low body mass index (p = 0.01) were also independently associated with a smaller BPD in multivariate analysis. CONCLUSIONS/SIGNIFICANCE: Despite early treatment in all positive women, one or more (a)symptomatic P.falciparum or P.vivax malaria infections in the first half of pregnancy result in a smaller than expected mid-trimester fetal head diameter. Strategies to prevent malaria in pregnancy should include early pregnancy

Estimation of gestational age from fundal height: a solution for resource poor settings

Short Title: Estimation of gestational age from SFH 2 SUMMARY Many women in resource poor settings lack access to reliable gestational age assessment because they do not know their last menstrual period (LMP), there is no ultrasound and methods of newborn gestational age dating are not practiced by birth attendants. A bespoke multiple-measures model was developed to predict the expected date of delivery (EDD) determined by ultrasound. The results are compared with both a linear and a non-linear model. Prospectively collected early ultrasound and serial symphysis-pubis fundal height (SFH) data were used in the models. The data were collected from Karen and Burmese women attending antenatal care on the Thai-Burmese border. The multiple-measures model performed best resulting in a range of accuracy depending on the number of SFH measures recorded per mother (for example 6 SFH measurements resulted in a prediction accuracy of ± 2 weeks). SFH remains the proxy for gestational age in much of the resource poor world. While more accurate measures should be encouraged we demonstrate that a formula that incorporates at least three SFH measures from an individual mother and the slopes between them provides a significant increase in the accuracy of prediction compared with linear and non-linear formulae also using multiple SFH measures

Fetal biparietal diameter measurements in Burmese and Karen pregnant women with and without malaria.

<p>The x-axis shows the gestational age (GA) in weeks, based on first trimester dated pregnancies on the Thai-Burmese border from 2001 to 2010. The y-axis depicts the fetal biparietal diameter measurement (BPD) in centimeters. The fetal BPD in pregnant women with malaria (red diamonds, n = 336) and in women without malaria (<b>+</b>, n = 3,443) between 16 and 24 GA weeks were superimposed on the 2.5^th, 50^th and 97.5^th centiles of a reference equation for this population <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0031411#pone.0031411-Rijken4" target="_blank">[29]</a>. Note that the majority of fetal BPD measurements in malaria infected women lie below the 50^th centile in both the main figure (16 to 24 GA weeks) and in the inset (17 to 20 GA weeks, where 90% (302/336) of the measurements in malaria infected women were obtained).</p

Selection of pregnant women.

<p>Selection of pregnant women.</p

Species, episodes and severity of malaria and mean BPD z-score of women infected between the first and second scan.

<p>Median [min-max], or mean (SD). BPD biparietal diameter; hyper = hyperparasitaemia (≥4% red blood cells infected), n.a. not applicable, P plasmodium.</p>#<p>Missing data n = 2.</p

Demographics of the refugee and migrant women from Thai Burmese border, 2001–2010.

<p>Median [IQR], or as indicated.</p><p>BMI body mass index, Hct Haematocrit at first consultation, MUAC middle upper arm circumference, NOC number of consultations.</p>+<p>between the 1^st and 2^nd scans.</p><p>*Weight gain from the first to the second scan; available from 301 in malaria and 2,677 in no malaria group.</p>#<p>Available from 292 in malaria and 2,626 in no malaria group.</p>$<p>Available from 314 in malaria and 3,044 in no malaria group.</p