Pregnancy and postpartum dynamics revealed by millions of lab tests

Pregnancy and delivery involve dynamic alterations in many physiological systems. However, the physiological dynamics during pregnancy and after delivery have not been systematically analyzed at high temporal resolution in a large human population. Here we present the dynamics of 76 lab tests based on a cross-sectional analysis of roughly 41 million measurements from over 300,000 pregnancies. We analyzed each test at weekly intervals from 20 weeks preconception to 80 weeks postpartum, providing detailed temporal profiles. About half of the tests take three months to a year to return to baseline during postpartum, highlighting the physiologic load of childbirth. The precision of the data revealed the effects of preconception supplements, overshoots after delivery, and intricate temporal responses to changes in blood volume and renal filtration rate. Pregnancy complications – gestational diabetes, pre-eclampsia, and postpartum hemorrhage – showed distinct dynamical changes. These results ..., Study Population
The study population consisted of individuals from the Clalit healthcare database, Israel's largest health maintenance organization (HMO). We considered all pregnancies of females aged 20 to 35 between 2003 and 2020. Information about pregnancies before 2003 is not available. We estimated the fraction of first pregnancies for the years 2010-2020 to reduce the influence of first pregnancies before 2003 which we cannot account for. For more information, see “stats.csv”.
Data Collection
Medical records were pseudonymized by hashing of personal identifiers and randomization of dates by a random number of weeks uniformly sampled between 0 and 13 weeks for each patient and adding it to all dates in the patient diagnoses, laboratory, and medication records. This randomization does not affect timing relative to delivery. 
We examined the timeframe of 60 weeks before delivery to 80 weeks after delivery for all documented labours within our study population. 0 is denoted as the w..., , # Pregnancy and postpartum dynamics revealed by millions of lab tests

[https://doi.org/10.5061/dryad.1c59zw44t](https://doi.org/10.5061/dryad.1c59zw44t)
[](https://doi.org/10.5281/zenodo.13996864)

The dataset contains summary statistics on lab tests from >300K pregnancies in Israel in the period 2003-2020 who are members of \"Clalit Healthcare\", Israel's largest HMO. It spans 110 different tests at weekly resolution.

Where BMI information was available, the measurements were grouped into three: 15-18.5, 18.5-25, and 25-30. These test results are also included in the ungrouped dataset.

In addition, the dataset contains the same information for 3 common complications: Postpartum hemorrhage (PPH), gestational diabetes mellitus (GDM), and pre-eclampsia. The dataset of these pregnancies is brought at a 4-week resolution due to a lower number of measurements.

See *Methods* for more details on dataset curation.

# Description of the data and...