For most women, a pregnancy ends with a baby and a postnatal check. A study published on Oct. 6 in BMJ Medicine argues that the pregnancy itself may leave a record worth reading for years afterward. Researchers who followed 1.4 million women in England found that complications in the latest pregnancy, and also in earlier ones, were linked to higher rates of high blood pressure, type 2 diabetes, heart disease and chronic kidney disease.

The paper is observational and its authors say it cannot show that complications cause later disease. What it does offer is a broad, careful map of who is at higher risk.

What the Study Did

The team, from the MuM-PreDiCT research consortium and including researchers at King's College London and the University of Birmingham, used the UK's Clinical Practice Research Datalink, a database of primary care records, linked to hospital data. It included 1,432,795 women aged 15 to 49 who were pregnant between 2000 and 2022.

They examined 10 complications: gestational hypertension, pre-eclampsia, gestational diabetes, miscarriage, stillbirth, placental abruption, preterm birth, small and large babies for gestational age, and postnatal depression. They tracked four outcomes from about six months after the latest pregnancy: cardiovascular disease, type 2 diabetes, hypertension and chronic kidney disease. Median follow-up was about four years.

The Familiar Links, Confirmed

The established associations held up, and they were large. Pre-eclampsia in the latest pregnancy was linked to a hazard ratio of 4.46 for later hypertension, and gestational hypertension to 3.85. A hazard ratio compares how quickly new cases appear in two groups, so a figure above four means a much faster rate than in women without the complication.

Gestational diabetes was associated with a sevenfold rate of type 2 diabetes (hazard ratio 6.99), plus raised rates of hypertension and cardiovascular disease, but not of kidney disease. Gestational hypertension and pre-eclampsia roughly doubled the rate of chronic kidney disease.

The Less Familiar Findings

The more interesting results involve complications that rarely feature in heart-risk conversations. Postnatal depression after the latest pregnancy was linked to a 35% to 56% higher rate of all four conditions. The hazard ratio was 1.56 for cardiovascular disease, 1.41 for type 2 diabetes, 1.36 for hypertension and 1.35 for kidney disease.

Other results were more modest. Stillbirth in the latest pregnancy was associated with type 2 diabetes (hazard ratio 1.67) and kidney disease (1.79). Placental abruption, when the placenta detaches early, was linked to kidney disease (1.67) and diabetes (1.38), associations the authors say have not been reported before. A baby born large for gestational age was tied to type 2 diabetes even without gestational diabetes (1.25 after excluding it).

One result ran the other way: women whose latest baby was small for gestational age had a lower rate of type 2 diabetes (0.77), though a higher rate of hypertension in earlier pregnancies.

Earlier Pregnancies Still Count

Most previous studies looked only at the latest pregnancy. This one asked about earlier ones too, and the signal persisted. A previous pre-eclampsia was linked to a hazard ratio of 2.85 for hypertension, and previous gestational diabetes to 6.18 for type 2 diabetes. That suggests the risk is not simply a short-term effect of one pregnancy.

The authors say their findings support recording a full reproductive history, not just the most recent pregnancy, when assessing a woman's cardiometabolic risk.

Relative Risk Is Not Absolute Risk

Hazard ratios sound dramatic, so context helps. Across the whole group, during about four years of follow-up, 3.5% developed hypertension, 1.5% type 2 diabetes, 1.1% cardiovascular disease and 0.4% chronic kidney disease. The absolute risks for most women remain small in the short term, and the study follows women in their 30s on average.

There are other caveats. A complication, the authors write, is better seen as a marker of underlying susceptibility than a cause, and hazard ratios should not be added across complications. Women with complications also see doctors more often, so more of their blood pressure and glucose problems may simply be found, a bias the authors say they cannot rule out. Ethnicity was missing for more than 20% of women, and diet and exercise were not recorded.

What Might Change

The authors point to practical gains. Postnatal depression and placental abruption are not part of widely used UK risk calculators such as QRISK3 and QDiabetes, and including them might improve early identification. They also see the postpartum period as a chance for blood pressure and glucose checks, lifestyle support and mental health care.

That fits a wider shift toward looking at who benefits from which test. Blogerroom's report on heart calcium scans found extra testing helped only some patients, and a wearable device that uncovered a hidden cause of high blood pressure showed how routine checks can miss drivers of the same condition. My view: a pregnancy history is cheap to collect, and this study makes a reasonable case for asking.

The study was funded by the Medical Research Council, the National Institute for Health and Care Research, the British Heart Foundation Data Science Centre and the HDR UK-Turing Wellcome PhD Programme. Anyone who has had a complicated pregnancy can mention it to their GP at routine check-ups. This article is general information, not medical advice.