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

Abstract

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.

Effect of gestational weight gain on placental weight: A single tertiary referral center study of Japanese women

“…Recently, some studies validated the appropriate gestational weight gain for different pre-pregnancy BMI categories based on the risk of adverse obstetric outcomes in Japan. 14,15,17,18 In the present study, we referred to pre-pregnancy BMI categories and recommended weight gain during pregnancy based on these studies (Table 2), because both participants of previous studies and those of the present study comprised only Japanese individuals, and we used validated placental weight accounting for gestational age and sex of newborns using a Japanese sample. 16 Overweight and obesity are often the consequence of an accumulation of unhealthy lifestyles.…”

“…The participants were categorized into five groups according to their BMI before pregnancy: group 1 (G1), <18.5 kg/m 2 ; group 2 (G2), 18.5 to <20.0 kg/m 2 ; group 3 (G3), 20.0 to <23.0 kg/m 2 ; group 4 (G4), 23.0 to <25.0 kg/m 2 ; and group 5 (G5), > 25.0 kg/m 2 . 14,17,18 Gestational weight gain was calculated by subtracting the weight before pregnancy (kg) from the weight immediately before delivery (kg). Thus, for the subsequent analysis of pre-pregnancy BMI on the z-score of placental weight, gestational weight gain was categorized into "insufficient," "appropriate," or "excessive," based on the pre-pregnancy BMI according to criteria described by previous Japanese epidemiological study (Table 1).…”

“…Thus, for the subsequent analysis of pre-pregnancy BMI on the z-score of placental weight, gestational weight gain was categorized into "insufficient," "appropriate," or "excessive," based on the pre-pregnancy BMI according to criteria described by previous Japanese epidemiological study (Table 1). 14,15,17,18 Outcomes Birthweight and placental weight were measured by a midwife soon after delivery. The z-scores of birth weight were calculated using the "New Japanese Neonatal Anthropometric Charts".…”

Effect of gestational weight gain on preeclampsia among underweight women: A single tertiary referral center study in Japanese women

“…In addition to prepregnancy BMI, several studies have examined the correlation between gestational weight gain and obstetric outcomes in the recent years. Excessive gestational weight gain is associated with an increased risk of cesarean section, complicated deliveries, fetal acidosis, birth of large‐for‐gestational‐age infants, and postpartum depression 11–13 …”

“…Excessive gestational weight gain is associated with an increased risk of cesarean section, complicated deliveries, fetal acidosis, birth of large-for-gestational-age infants, and postpartum depression. [11][12][13] Women from Asian countries generally have a lower BMI than those from Western countries. 14 Compared to a high prepregnancy BMI, being underweight at the time of pregnancy has also been reported to be associated with preterm birth and fetal growth restriction.…”