MCA Doppler may be a useful tool to assess the health of small fetuses in the late third trimester. Redistribution may occur in the presence of normal umbilical artery Doppler and should be suspected when the HC/AC ratio is elevated.

No abstract

Objective: To investigate complications and outcome of pregnancies with male and female fetuses. Methods: A population-based study comparing all singleton deliveries between the years 1988 and 1999 was performed. We compared pregnancies with male vs. female fetuses. Patients with a previous cesarean section (CS) were excluded from the study. Statistical analyses with the Mantel-Haenszel technique and multiple logistic regression models were performed to control for confounders. Results: During the study period there were 55,891 deliveries of male and 53,104 deliveries of female neonates. Patients carrying male fetuses had higher rates of gestational diabetes mellitus (OR = 1.1; 95% CI 1.01–1.12; p = 0.012), fetal macrosomia (OR = 2.0; 95% CI 1.8–2.1; p < 0.001), failure to progress during the first and second stages of labor (OR = 1.2; 95% CI 1.1–1.3; p < 0.001 and OR = 1.4; 95% CI 1.3–1.5; p < 0.001, respectively), cord prolapse (OR = 1.3; 95% CI 1.1–1.6; p = 0.014), nuchal cord (OR = 1.2; 95% CI 1.1–1.2; p < 0.001) and true umbilical cord knots (OR = 1.5; 95% CI 1.3–1.7; p < 0.001). Higher rates of CS were found among male compared with female neonates (8.7 vs. 7.9%; OR = 1.1; 95% CI 1.06–1.16; p < 0.001). Using three multivariate logistic regression models and controlling for birth weight and gestational age, male gender was significantly associated with non-reassuring fetal heart rate patterns (OR = 1.5; 95% CI 1.4–1.6; p < 0.001), low Apgar scores at 5 min (OR = 1.5; 95% CI 1.3–1.8; p < 0.001) and CS (OR = 1.2; 95%CI 1.2–1.3; p < 0.001). Controlling for possible confounders like gestational diabetes, cord prolapse, failed induction, nonprogressive labor, fetal macrosomia, nuchal cord and true umbilical cord knots using the Mantel-Haenszel technique did not change the significant association between male gender and CS. Conclusion: Male gender is an independent risk factor for adverse pregnancy outcome.

Nuchal cord is not associated with adverse perinatal outcome. Thus, labor induction in such cases is probably unnecessary.

Meconium ileus, intestinal obstruction in the newborn, is caused in most cases by CFTR mutations modulated by yet-unidentified modifier genes. We now show that in two unrelated consanguineous Bedouin kindreds, an autosomal-recessive phenotype of meconium ileus that is not associated with cystic fibrosis (CF) is caused by different homozygous mutations in GUCY2C, leading to a dramatic reduction or fully abrogating the enzymatic activity of the encoded guanlyl cyclase 2C. GUCY2C is a transmembrane receptor whose extracellular domain is activated by either the endogenous ligands, guanylin and related peptide uroguanylin, or by an external ligand, Escherichia coli (E. coli) heat-stable enterotoxin STa. GUCY2C is expressed in the human intestine, and the encoded protein activates the CFTR protein through local generation of cGMP. Thus, GUCY2C is a likely candidate modifier of the meconium ileus phenotype in CF. Because GUCY2C heterozygous and homozygous mutant mice are resistant to E. coli STa enterotoxin-induced diarrhea, it is plausible that GUCY2C mutations in the desert-dwelling Bedouin kindred are of selective advantage.