Difference in Z scores of placental weight and fetal/placental weight ratio by mode of delivery

Trimester-Specific Association of Maternal Exposure to Fine Particulate Matter and its Components With Birth and Placental Weight in Japan

OBJECTIVE

We investigated which trimester of exposure to PM2.5 and its components was associated with birth and placental weight, and the fetoplacental weight ratio.

METHODS

The study included 63,990 women who delivered singleton term births within 23 Tokyo wards between 2013 and 2015. Each day, we collected fine particles on a filter, and analyzed their chemical constituents, including carbons and ions. Trimester-specific exposure to each pollutant was estimated based on the average daily concentrations.

RESULTS

Over the third trimester, sulfate exposure tended to be inversely associated with birth weight, and decreased placental weight (difference for highest vs lowest quintile groups = -6.7 g, 95% confidence interval = -12.5 to -0.9). For fetoplacental weight ratio, there was no relationship.

CONCLUSIONS

Sulfate exposure over the third trimester may reduce birth weight, particularly placental weight.

Low placental growth factor levels and high soluble endoglin levels at 26-31 weeks of gestation precede light placenta with and without relatively heavy infant, respectively: A retrospective cohort study

AIM

Our aim was to examine whether serum levels of placental growth factor (PlGF) and soluble endoglin (sEng) at 19-25 and 26-31 weeks of gestation were associated with the occurrence of the 9-block categorization of placenta weight (PW) and fetal/placenta ratio (F/P ratio).

METHODS

We performed a retrospective cohort study in 1391 women with singleton pregnancy. Serum levels of PlGF and sEng were measured by enzyme immunosorbent assay. A light placenta was defined as PW ZS < -1.28 SD. Based on the PW (light, normal, and heavy) and F/P ratio (relatively heavy, balanced growth, and relatively small), 9-block categorization were performed. Multivariable logistic regression analyses were performed.

RESULTS

Low PlGF at 26-31 weeks was an independent risk factor for the birth of infants belonging to Block A (light placenta and relatively heavy infant), after adjusting for prepregnancy body mass index and serum levels of sEng. High sEng at 26-31 weeks was an independent risk factor for the birth of infants belonging to Block D (light placenta and balanced growth of infant), after adjusting for past history of either preeclampsia or gestational hypertension, high pulsatility index of uterine artery flow velocity waveforms in the second trimester, and serum level of PlGF.

CONCLUSIONS

Low PlGF levels at 26-31 weeks of gestation may precede a light placenta and relatively heavy infant (Block A), and high sEng levels at 26-31 weeks of gestation may precede a light placenta and balanced growth of infant (Block D).