Fetal bradycardia and acidosis during maternal parenteral iron: Case reports and literature review.

Iron deficiency anemia is an important problem among pregnant women, and intravenous (IV) iron infusions have been increasingly used. Whether fetal monitoring is required during infusion has been debated, with a recent guideline by Hematologists recommending against such. We report two cases of fetal bradycardia after iron isomaltoside (IIM), in women with otherwise good maternal and fetal health. Both developed dyspnea with desaturation minutes from infusion, followed by persistent fetal bradycardia. Both underwent category 1 CS, with cord arterial pH of 7.08 and 6.94 respectively. Upon literature review, only three case reports on fetal bradycardia in IV iron were identified. For older IV iron formulations, a case was reported after IV dextran test dose, while two cases after ferric gluconate were reported. For the new formulation IIM, only one case was reported so far, but in a woman with Crohn's disease and intrauterine growth restriction. IV iron in pregnancy carries risk of anaphylactic or hypersensitivity reactions, even with the newest formulations and in women with good maternal and fetal health. While rarely reported so far, fetal bradycardia is a possible consequence, commonly preceded by respiratory symptoms. Fetal monitoring should therefore be considered during infusion.

Nomogram for fetal limb bones in Chinese ethnicity.

OBJECTIVE: To construct fetal limb bone nomograms in the Chinese ethnic population. METHODS: This was a prospective cross-sectional study on singleton pregnancies between 12 and 37 weeks of gestation. Femur, tibia, fibula, humerus, ulna, radius, and foot length were measured in a standardized manner by one of the three sonographers. Each fetus's measurements were only included once and those who developed maternal or fetal complications were excluded. Fractional polynomial regression model was used to obtain the 3rd, 10th, 50th, 90th, and 97th centiles for each of the limb measurement. Z-score for the 50th centile of each fetal limb measurement was then compared with published nomograms derived from other populations. RESULTS: Of the 843 scans performed, 775 were included in analysis after excluding conditions such as pre-eclampsia, chromosomal abnormalities, single umbilical artery and skeletal dysplasia. Comparison with other populations showed that Chinese had shorter fetal limb bone lengths than the Caucasian and Afro-Caribbean populations. CONCLUSION: This study established nomograms for all the fetal limb bones in the Chinese ethnic population, which showed lengths comparatively shorter than Caucasian and Afro-Caribbean nomograms. This would reduce the false alarm of short fetal limb bone lengths and its consequent anxiety and intervention.