Design: Systematic review and meta-analysis of observational studies
Population: 10 studies, 2,118,215 pregnancies; 8,325 exposed within 6 months before conception
Primary outcome: Miscarriage, anomalies, preterm birth and other maternal-perinatal outcomes
Effect: No clearly detectable increase in any outcome; pre-eclampsia OR 0.87 (0.78-0.98)

A meta-analysis in Med (published 29 September 2026) pooled ten observational studies covering 2,118,215 pregnancies, 8,325 of them exposed to a GLP-1 receptor agonist in the six months before a positive pregnancy test.

Pooled estimates showed no clearly detectable rise in miscarriage or intrauterine death, congenital anomalies, preterm birth, hypertensive disorders, gestational diabetes, abnormal fetal growth or excess weight gain. Pre-eclampsia was slightly less common with exposure (OR 0.87, 95% CI 0.78-0.98), but that estimate came from only two datasets. Results did not differ by indication - diabetes or weight loss.

The question is pressing because weight-loss prescribing has put these drugs in front of large numbers of women who may conceive, sometimes because weight loss restored ovulation. The authors are explicit that their data do not establish safety: heterogeneity was substantial, confounding by indication is likely, and the exposed numbers per outcome are modest.

Practically, this is reassurance for a woman who conceived while on treatment, not a licence to continue. Standard advice remains to stop GLP-1 receptor agonists before planned conception, allowing for the washout periods in each product's label.

Discuss contraception when starting a GLP-1 receptor agonist - weight loss can restore ovulation
Stop the drug once pregnancy is recognised, and before planned conception as the label advises
Reassure a woman who conceived on treatment that pooled data show no clear rise in adverse outcomes
Do not cite the lower pre-eclampsia estimate as a benefit - it rests on two datasets

Why it matters

Weight-loss prescribing has made unplanned exposure common, and this is the largest pooled answer so far for counselling.

The statistics, in plain English

The pre-eclampsia odds ratio of 0.87 (0.78-0.98) just excludes 1.0, but with only two datasets behind it one unusual study could move it. For the other outcomes the intervals crossed 1.0: no detectable difference, which is not the same as no difference.