Author Correction: Gestational weight gain and foetal acidosis in vaginal and caesarean deliveries: The Japan Environment and Children’s Study

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Maternal pre-pregnancy body mass index and foetal acidosis in vaginal and caesarean deliveries: The Japan Environment and Children’s Study

A high maternal body mass index (BMI) is associated with increased risks of asphyxia-related neonatal morbidity. We evaluated the association between maternal pre-pregnancy BMI and foetal acidosis while accounting for the mode of delivery. Participants from the Japan Environment and Children’s Study with singleton pregnancies after 22 weeks of gestation who gave birth during 2011–2014 were included. The participants (n = 71,799) were categorised into five groups according to the pre-pregnancy BMI: G1 (BMI < 18.5 kg/m2), G2 (18.5 to < 20.0 kg/m2), G3 (20.0 to < 23.0 kg/m2), G4 (23.0 to < 25.0 kg/m2), and G5 (≥ 25.0 kg/m2). Foetal acidosis was defined as umbilical artery pH (UmA-pH) < 7.20 or < 7.10. Multiple logistic regression analyses were used to evaluate the effect of pre-pregnancy BMI on foetal acidosis risk, accounting for the mode of delivery. In Japanese women, pre-pregnancy BMI ≥ 25.0 kg/m2 significantly increased the likelihood of foetal acidosis in newborns delivered vaginally. We found no association between pre-pregnancy BMI and foetal acidosis in newborns delivered via caesarean section. Counselling for body weight control before pregnancy and adequate management and selection of the mode of delivery in pregnant women with a high BMI who are in labour may be essential to avoid foetal acidosis.

Umbilical Coiling Index, A Predictor of Perinatal Outcome

Umbilical cord (UC) represents the “life source”, or the “entry and exit” point of humans which is the only source of energy. It is essential for the development, well-being, and survival of the nourishing baby. The characteristic of the coiling of the umbilical cord makes the cord a structure that is both flexible and strong and provides resistance to external forces which could compromise the blood flow to the foetus. UC is vulnerable to kinking, compressions, traction, and torsion, which may affect the intrauterine life and perinatal outcome due to coiling. One complete spiral of 360º of the umbilical vessels around each other is defined as Umbilical Coil. Abnormal coiling is defined as UCI less than the 10th percentile (i.e., Hypocoiled cord), UCI more than the 90th percentile (i.e., Hypercoiled cord), and the UCI between 10th and 90th percentile is Normocoiled cord. According to the literature studies, hypercoiled cords are usually associated with intrapartum foetal acidosis and asphyxia, foetal growth restriction, vascular thrombosis, and cord stenosis while the increased incidence of foetal demise, intrapartum FHR deceleration, low APGAR scores, preterm delivery, chorioamnionitis, structural and chromosomal abnormalities, and operative delivery have been associated more with hypocoiled cords. Hence, if the umbilical coiling index can be measured reliably in utero by ultrasound antenatally, then in future, it might become a promising prognostic marker for a better pregnancy and adverse foetal outcome.

Gestational weight gain and foetal acidosis in vaginal and caesarean deliveries: The Japan Environment and Children’s Study

Inappropriate gestational weight gain (GWG), either above or below the recommended values, has been associated with an increased risk of adverse obstetric outcomes. To evaluate the risks of GWG for foetal acidosis according to pre-pregnancy body mass index (BMI) and mode of delivery, we analysed women with singleton pregnancies between 2011 and 2014 in the Japan Environment and Children’s Study. Participants (n = 71,799) were categorised according to pre-pregnancy BMI. GWG was categorised into insufficient, appropriate, or excessive. Foetal acidosis was defined as umbilical artery pH (UmA-pH) < 7.20 or < 7.10. Multiple logistic regressions were performed for each BMI category to identify the risks of GWG for foetal acidosis, accounting for the mode of delivery. Excessive GWG was significantly associated with increased foetal acidosis in overweight women and in women whose pre-pregnancy BMI was 23.0–25.0 kg/m2 especially in those with vaginal deliveries. Conversely, excessive GWG was not significantly associated with increased foetal acidosis in obese women and in women whose pre-pregnancy BMI was ≥ 25.0 kg/m2.